Model Engine Maker

Supporting => Vehicles & Models => Topic started by: jadge on May 31, 2015, 10:51:52 AM

Title: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on May 31, 2015, 10:51:52 AM
As promised in my introductory thread here are some sample pictures of progress on my traction engines. Here are the two engines, and assorted parts in progress. I am building the engines according to what interests me at the time, rather than in a logical order. I started with the gears, because I like gears:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Engines1.JPG)

And from the other side, showing the differential. The bevel gears are true bevel gears, rather than the normal approximations, made on my CNC mill:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Engines2.JPG)

I've made the pistons and piston rods, but instead of the normal aluminium pistons in this scale I chose to design and make hollow cast iron pistons; the two halves screw together. The stiffening ribs were designed using a FEA software package. The pistons are oversize and will be ground to final size once the liners are made and fitted:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Pistons_and_Piston_Rods.JPG)

I have recently finished the brake shafts and nuts. This was an interesting exercise as I have never cut a square thread before. It worked out better than I thought it might:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Brake_Shafts.JPG)

Here are the serial taps I made to cut the square thread in the bronze brake shaft nuts:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Square_Thread_Taps.JPG)

I've also been busy making the studs and nuts for the engines, mostly " and 5/16" BSF, I still have some 2BA studs to go, and assorted bolts:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Nuts_and_Studs.JPG)

I am currently making the gear change mechanism. This has been redesigned as the drawings are a fantasy. Having 3D printed the parts to make sure it worked as intended I am now converting the parts to metal. Once finished I'll have a go at the water pump. This has been completely redesigned, as I think the original one, as drawn, has a ram that is way larger than needed. I have also taken the opportunity to redesign the internals to incorporate proper winged valves, as per full size. Here's a section of the 3D CAD model:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Water_Pump_Assembly.JPG)

My morning tug pilot duty has been cancelled due to wind and rain, so I've got the rest of the day in the workshop!

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Dave Otto on May 31, 2015, 04:38:09 PM
Very nice work!

It appears that you keep your toys in the kitchen? you must be single :lolb:

Dave
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: b.lindsey on May 31, 2015, 04:53:07 PM
Wow, that is some heavy iron Andrew. But well done from the looks of them too!!

Bill
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: peatoluser on May 31, 2015, 04:59:13 PM
very impressive work indeed!
very professional looking shop made taps as well. what size are they and how did you go about making them?
thanks for taking the time to post the pictures

peter
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on May 31, 2015, 10:24:32 PM
Dave: Any resemblance to a kitchen is purely accidental. It is actually the assembly hall, casting storage area, and potential workshop - spot the coil winder, dead weight pressure tester and Pultra lathe on the table. I just happen to cook in the same area. And yes, I am single, the last girlfriend left in a huff muttering about lifestyle issues.

Bill: Indeed they are big, the engines will weight over a 1000 lbs each when finished. But they are an antidote to the electronics I do in the day job where the components are getting so small I can't see them. One sneeze and that's the entire packet of resistors gone for good.

Peter: The brake shaft square thread is " OD and 8 tpi. I'll dig out some pictures and post an outline of how I made them tomorrow. I see that you are in Liverpool; I was there in the late 70s doing my first degree at the university.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: steamer on June 01, 2015, 03:05:18 AM
That's beautiful work Andrew!   I l really like that pump! :ThumbsUp:

Dave
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on June 01, 2015, 11:45:05 AM
Dave: Thanks for the compliment. I had quite a lot of help over on TractionTalk from somebody who designed pumps commercially. He mentioned a whole load of parameters I hadn't thought of and challenged me to show that the pump wouldn't cavitate on the suction stroke. It took a while but I managed enough theory to convince myself that it wouldn't cavitate. He also suggested glass filled PTFE for the wing valves rather than the bronze I was intending to use. I will be interested to see how the glass filled PTFE behaves when being machined, as pure PTFE is a bit of a pig when trying to hold exact sizes.

Peter: As promised here is an outline of making the taps. The taps are made from silver steel (aka drill rod). Cutting the basic threads, turning the shank and forming the drive square are all straightforward. The taps are serial, ie, taps 1 and 2 do not cut to the full depth. I took values of 41%, 81% and 100% of full depth for each tap from Machinery's Handbook.

For cutting the flutes I used 1/8" radius cutter  on the horizontal mill, the depth of cut being determined from a CAD sketch, adjusted until it looked about right. Note the home made extension to the dividing head tailstock to avoid cutting into same:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Fluting_Taps_MEM.JPG)

The taps were hardened in the electric furnace, quenched in brine and then tempered at 215C. I ground a relief on the tapered portion of the taps as it gave me an opportunity to try out the drill and tap grinding accessory I bought last year, although it would have been just as easy to use a needle file before hardening:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Grinding_Tap_Relief_MEM.JPG)

I made the two nuts as one to start with, to ease holding. In this picture the threads have been counterbored with a " slot drill to shroud the sharp edges where the thread starts:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Square_Threads_MEM.JPG)

I made a couple of boo-boos when making the taps. First, I failed to notice that the size of the small end of the taps should vary as well as the depth of thread. If I'd done that the taps might have required less effort when cutting the thread. Second, I failed to harden the first tap properly, so it twisted slightly when being used.

Nevertheless it was an interesting exercise, and it's another tick in the been there tried that boxes.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jo on June 01, 2015, 12:09:40 PM
Dave: Any resemblance to a kitchen is purely accidental. It is actually the assembly hall, casting storage area, and potential workshop - spot the coil winder, dead weight pressure tester and Pultra lathe on the table. I just happen to cook in the same area.

:lolb: Sounds like my dining room table.. I just happen to eat off it.

Jo
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: pgp001 on June 01, 2015, 01:08:18 PM
I bet your kitchen assembly hall floorboards are groaning a bit  ;D

Phil
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: peatoluser on June 01, 2015, 04:11:19 PM
Andrew,
thanks for the photos/explanation of tap making. specially the depth ratios. filed away for future use

peter

(apologies, for some reason I called you Dave! - (i blame the beer!)
post properly amended
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: fumopuc on June 01, 2015, 06:59:08 PM
Hi Andrew, you are showing us some impressive work.
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Don1966 on June 02, 2015, 12:56:18 AM
Nice setup you have Andrew and very impressive work on those traction engines.

Don
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on June 02, 2015, 10:24:26 PM
Thanks for the compliments. I'm always amazed at the speed with which other people knock out great looking work. It seems to take me ages to achieve anything; although I do keep having diversions into the engineering behind the design.  :D

Phil: The assembly hall is nothing compared to the weight of the machines in the workshop! Unusually the floors in my bungalow are concrete, so there shouldn't be a problem. The downside is that the central heating pipes are buried in the floor, so if I have a leak............. :(

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: pgp001 on June 02, 2015, 11:19:26 PM
Andrew

I am following your build with interest as I have a set of drawings and castings waiting under the bench for a the 1" version of the same engine.

Burrell's are in my blood so to speak, we used to own a full size engine called "Dalesman" a 6HP DCC 1912 road loco a few years ago.
At the same time we also had a 10HP Fowler road loco "Titan", but the Burrell was always my favourite on the road.

A friend of mine has 99% finished the restoration of a 6HP SCC Burrell which should be out this season.

Phil
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on June 03, 2015, 10:15:54 PM
Phil: You're way ahead of me as you have owned and operated full size. I can always dream, although I have a covenant on my property banning the operation of traction engines.  >:(

A lottery win, that's what I need, not only a traction engine but a P51D Mustang too. A Spitfire would be good, but even a lottery win may not be enough for one!

I wasn't intending to do a build diary as such, but if people are interested I am happy to detail the design and machining of some of the more interesting parts.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on June 05, 2015, 11:45:07 AM
Ooopsie, looks like I was in the wrong place, and I've been downgraded to a supporting role.  :'(

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jo on June 05, 2015, 11:46:38 AM
Same as my BB1  ;)

Jo
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on October 09, 2015, 11:06:13 AM
I have been struggling with the gear change mechanism over the past few months. What should have been a set of simple parts to make turned out to be anything but; let alone trying to get the mechanism to actually work.

As an antidote I've returned to gears, which I find fascinating. Almost all the gears on the engines are already made; the only ones left are on the governor. I've just spent a happy couple of evenings modelling the mitre bevel gears in 3D CAD. The LSM drawings are close on OD and face angle, but not quite right, and give no other details apart from 18 teeth and 18DP. Here is the assembly of the two gears to check meshing and spacing, as there are almost no dimensions on the drawing for the governor casting:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Governor_Bevel_Gear_Assembly.JPG)

For scale the OD is just over 1" and the involute tooth form is for a 25 tooth equivalent spur gear, as per Tregold's approximation. It should be possible to machine these on the CNC mill, roughing with a 1.5mm ballnose cutter and a final pass with a 1/32" ballnose cutter to clean out the small end roots. Some quick CAM programming shows it should take 22 hours to machine at the maximum speed of my CNC mill, ie, 5000rpm. So I'm considering buying a high speed spindle to bolt along side. It means I lose the ability to use tool tables, but I can cope with that for a setup like this where there are only two tools.

I've also added a 3D PDF of the assembly. By clicking on the PDF you should be able to zoom, pan and rotate the gears.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jasonb on October 09, 2015, 11:48:01 AM
A timely post Andrew as I soon have a set to cut for my Tidman engine governor at 2:1 and about 2.5" dia for the larger wheel. I'll be following along even though I will have to opt for parallel depth method.

Nicely drawn too, did you cut-extrude one gear and then place that in a circular pattern?
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on October 10, 2015, 10:47:12 AM
The base gear was drawn by constructing planes and axes representing the pitch cone angle and the face angle, plus lines representing the addendum and dedendum. Some while ago I found a DOS utility on the internet that generates DXF outlines of 20PA 1DP gears from 10 to 200 teeth. An appropriate DXF is imported and all bar one tooth is deleted. That is then imported as a sketch onto the plane representing the back face. It is not exact as the back face is curved in reality, but the differences are small. In an ideal world the sketch is then lofted with a point at the origin and the resultant tooth then circularly patterned. Needless to say Geomagic is not that simple, I cannot get the loft to a point to work. So I use a 2 thou square instead. The circular pattern function seems to have a wobbly if there is overlap of the repeated shape (?), so the square at the origin is actually 7 thou above the origin. The errors caused by this are small, may be a thou or two at most, and are reduced by a factor of 18 when the model is scaled for 18DP. Here is the 1DP gear with the construction geometries:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Governor_Bevel_Gear_1DP.JPG)

I looked at using the parallel depth method for the design of these gears some while ago, but it all got very messy and either gave fractional DPs, or gears that weren't going to fit without a major re-design.

By playing with the CAM software I've got the machining time down a bit, but there is really no alternative to having a high speed spindle.  :) When I made my 6DP bevel gears in cast iron I was running the 4mm cutter at 4000rpm, so for the small cutters I need here running at 5000rpm is definitely pedestrian.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jasonb on October 10, 2015, 01:16:14 PM
Thanks Andrew, I'll have a better study of the drawing later.

I suppose you could print them out and get some lost wax brass castings done. My diff gears are cast but they do run a lot slower than a governor, suppose it depends on how much belt work you are ever liekly to do. MAybe even get them printed in metal?
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on October 10, 2015, 08:41:33 PM
A strange thing happened today; I actually made some parts without having to scrap them and do it again properly.  :)

I tackled the worm and worm wheel adjuster for the governor. The drawings are somewhat lacking in detail, so I mostly ignored them. Rather than muck about cutting an Acme thread worm I chose to use a V-thread; in this case 7/16" UNC. For some unknown reason I already had a threading insert for 14 tpi UN series, which helps. Here are the two worms and worm wheels:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Governor_Worm.JPG)

By my normal standards these are teeny weeny. The worm wheel was cut using a spiral flute tap as a hob. Last time I tried this was 40+ years ago, while I was at school. It worked then and it worked now:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Hobbing_Worm_Wheel.JPG)

Just the governor bevel gears to go now, and that will be all the gears for the engines finished.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on November 01, 2015, 08:46:37 PM
Interspersed with weeding and digging the vegetable patches it has been a nutty time in the workshop this weekend. I've made all the 3/8" BSP nuts, and a few other parts, needed for the water pumps and boiler feed valves:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_BSP_Nuts.JPG)

The embryo nuts were made on the Britan. First operation was to face off, chamfer, drill thru, bore out to minor diameter of the thread and part off. Second operation, using a backstop, was face to length and chamfer the second end. All pretty straightforward stuff, apart from drilling the brass; in the end I stoned the edges off the drill. Given that it's a left hand stub drill I don't suppose I'll be using it for anything else.  :) It is, however, the first time I've used a boring bar on the Britan:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Britan_Boring.JPG)

I could have threaded the nuts with a BSP tap on the Britan, but wouldn't be able to thread the complete depth of the nut due to the tap lead. By screwcutting on the centre lathe I can get within one thread pitch of the bottom. It was also an excuse to buy a new toolholder for the size 11 inserts, as the size 16 inserts I normally use are too big:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Screwcutting_BSP.JPG)

After a bit of faffing about with a couple of trial nuts I got the screwcutting down to less than 3 minutes per nut at a conservative 260rpm.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jasonb on November 01, 2015, 08:55:01 PM
Look good Andrew, did you cut the thread in one pass or several?

I see you have an article on the Britan in the latest MEW, will have a read of that in teh week.

J

Not flying this weekend or were you fogged in? It has been very clear hear both days.
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on November 02, 2015, 11:26:48 AM
Jason: The threads were cut in several passes. Four passes at 20 thou total cut each, plus a pass and spring pass at 15 thou total cut. That got me to the arbitrary reading of 105 on the cross slide dial. A quick check with the external 'gauge' and a final cut at a reading of 102, plus one or two spring passes at the same setting. Quicker to do than write about. That's the beauty of a high speed threading unit, no faffing about with thread dial indicators, and an automatic trip at the end so you can run the tool to within a thou or so of the shoulder. The spring passes produced rather odd swarf. For most cuts the brass comes off as a fine spray, as one would expect. However, for the spring passes it comes off as a thin crinkly ribbon. Never seen brass behave like that before. If anyone is curious I can post a picture.

No flying this weekend, but I'm tug pilot next Saturday. Both weekend days were a bit misty and Sunday went completely pear-shaped. It started a bit misty but then got a lot worse. It fooled the gliding club as on the webcam mid-morning the gliders and winch were out and ready, but you couldn't see more than a 100 yards.

I finally got around to writing the article on the Britan, sent it off, and got an email back from Neil saying it had been expedited into the forthcoming issue.  :o

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jasonb on November 02, 2015, 11:45:11 AM
I think I have had similar swarf, when taking a wide cut and feeding slowly

(http://img.photobucket.com/albums/v156/jasonballamy/Engineering/Cameron%20Steam%20Pump/IMAG3359_zpsbcfc585e.jpg)

I also find the **GT tips will produce curly brass swarf which may be due to their higher top rake than the usual shallow rake on a HSS tool
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on November 02, 2015, 08:06:34 PM
Jason: That's the swarf type! I've only ever seen it during screwcutting with shallow depths of cut. Having just looked at some of the swarf under a magnifying glass it is of a V form. I screwcut by plunging straight in so the tool is cutting on both flanks. Thus the swarf seems to mirror the shape of the tool. It is as if each small piece of swarf cannot escape and so attaches to the next piece to produce a long curl. Certainly the crinkly swarf is not thrown off in the energetic shower that brass normally produces.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on December 08, 2015, 12:38:47 PM
I am making slow, but generally positive, progress on the water pumps. The wing valves are made, as are the gunmetal valve bodies that screw into the main casting. Here are one set of wing valves, plus a set installed in the valve body:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Wing_Valves.JPG)

The wing valves are made from glass filled PTFE. It's the first time I've used this material. It's waaaay nicer than virgin PTFE, which is 'orrible stuff for holding tolerances. With the glass filled PTFE it is easy to hold a few tenths.

After a false start I've also made the blanks for three rams. Material is 303 stainless steel and with a bit of fiddling on setup, and a lot of sparkout passes, I got the 10" blank parallel to within a tenth or two:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Grinding_Water_Pump_Rams_MEM.JPG)

Next job is to hacksaw the ram blanks to length and finish the machining. The plan this time is to not let the hacksaw slip and damage the surface.  :facepalm:

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on January 09, 2016, 09:09:54 PM
Hi Andrew,   I hope the hacksaw didn't slip!     Your water pump looks different to mine.  I'm using ball valves as per Filby drgs.
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on January 10, 2016, 11:18:26 AM
Terry: Fortunately the hacksaw didn't slip second time around!

My water pump looks different because I have completely re-designed it. There were persistent rumours on the forums that the pump as drawn was over-sized. Having run through the calculations for steam, and hence water, consumption it certainly seems to be. The ram is now 17mm (convenient as I have a 17mm reamer) rather than the original 7/8". While redesigning the ram I took the opportunity to alter the internals to use wing valves as per full size. I also changed some of the internal passages to ensure that there were no choke points in the flow. Here's a picture of the parts for one pump of the three I am making:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Water_Pump_Parts.JPG)

Three pumps? That's because I'm making one for a friend who is building the same engine. Apart from the main casting the only parts in the picture I didn't make are the M4 nuts, although I did buy a length of hex steel just in case! It will probably get used when I make the nuts/bolts for the wheel hubs. Speaking of which it's a nice day for a change so I'm now off to angle grind and weld parts for the wheels.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on January 10, 2016, 01:45:16 PM
beautiful work
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: zeeprogrammer on January 10, 2016, 01:56:34 PM
Nice family shot and excellent work.

Just caught up on this thread. Wish I'd been more active earlier.
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on January 10, 2016, 05:41:56 PM
It might be best if those of a sensitive disposition look away now! The wheel welding isn't pretty, although in my defence it's the first time I've done any serious arc welding. However, I don't think it's going to fall apart, and I hope that once I've used the angle grinder to remove the spatter, and odd lump, plus a good dollop of U-Pol it'll look alright:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Front_Wheel_-_Welding_MEM.JPG)

The wheel jig seemed to work fine and kept everything more or less in line. Not perfect by any means, but probably better than the originals!

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on January 18, 2016, 10:42:44 AM
Hi Andrew,   I wonder if you have made the expansion link yet, and if so is the lsm drawing ok?  I know that the conrod drawing is a joke  and wanted assurance from a tech expert before I cut metal.               Cheers              Terry
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on January 31, 2016, 08:02:27 PM
Terry: I'm embarrassed to say that I've only just seen your post regarding the expansion link. :embarassed:  I made an expansion link and die block in gauge plate to the LSM drawings, but that was for somebody on the TT forum. He had a professionally built engine, but it was rather worn and he was replacing parts as required. Once I get on to the motion work I plan to re-design the valve gear, but that is quite a way in the future. Some people say that the LSM valve gear design leaves something to be desired, but others who have engines built to the drawings say they run fine. Take your pick!

This afternoon after wielding a hot arc welder I have finished welding all four front wheel rims and T-rings:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Front_Wheel_Rims_MEM.JPG)

I'm getting better at arc welding. Once I've finished all the wheels I'll be good enough to start again and make the wheels to a proper standard. The next welding job is to turn 32 quadrants into the T-rings for the rear wheels.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on February 26, 2016, 08:57:38 PM
Elsewhere on this forum I mentioned that I'll try and post about a few more parts already made for my traction engines. For those that want more detail I run a build diary on TractionTalk under sobriquet 'oly2brf5'. On the same forum I am running a theory thread, although it has been in obeyance for a while due to work pressures. On the Model Engineer forum I am also involved in a thread on the theory and design calculations for steam injectors, although again it is temporary obeyance.

Now on to parts - in this post bevel gears, because I like gears. My traction engines have a differential based on two bevel gears and three bevel pinions. Traditionally there are two ways to cut approximations to bevel gears using standard equipment.

The first method uses an involute gear cutter, takes three passes and results in a tapered tooth form. The first pass is on the axis, followed by two offset passes that widen the space between teeth at the outer edge of the gear. I have made bevel gears using this method in the long distance past. However, there are two problems, the first concerning the involute cutter. It has the correct curvature for the involute form at the outer edge of the teeth, but since it has to pass through the narrower gap at the inner end it is narrower than a standard cutter of the same DP. These cutters are normally stamped 'BEVEL'. However, they do not seem to be available now - when I made the bevel gears all those years ago I had the facilities of the Royal Aircraft Establishment main workshop at Farnborough behind me.  :ThumbsUp: The second issue is the curvature of the teeth at the inner edge is not correct, and needs adjusting with a file or similar.

The second method treats the teeth as being constant depth, and can be cut in three passes with a standard involute cutter. However, in this method the gears are designed using the DP at the inner edge, not the outer edge as is standard. This means that it is very difficult to design gears to fit into an existing design while retaining an integer value for the DP.

Now, if I could design the bevel gears in 3D CAD I wondered if it would be possible to make proper straight tooth bevel gears using a 4-axis CNC mill? The answer was yes! The design process was quite long winded. It's one thing to pontificate about gear design but quite another to put numbers on things. For instance everyone knows that the tooth form is based on the involute of a circle, but which part of the involute and which circle? It turns out that it is the involute of the base circle, the diameter of which is the diameter of the pitch circle times the cosine of the pressure angle. Having drawn the gears in 1DP I created an assembly in CAD to check the meshing and face to face distance (note the undercutting of the pinion teeth):

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Bevels_MEM_1.JPG)

The observant might note that the teeth on the bevel gears look rather rack like for a 36 tooth gear. This is because the shape of the tooth is determined not by the number of teeth on the bevel gear, but on the 'equivalent' spur gear. The number is given by the number of teeth on the bevel gear divided by the cosine of the face angle. For my pinion this gives a value of 10.3 instead of 10, so use 10 teeth, ie, no change. However for the gear we get a value of 134.5 instead of 36, so use 135 teeth. The method is known as Tregold's approximation. To get the CAD models for the 6DP gears I need just use the CAD to scale the gears by one sixth.

That's enough flavour of the theory, onto the practical. Here are all the gear blanks and one of the pinion blanks ready on the 4th axis of the mill:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Bevels_MEM_2.JPG)

Note that the pinion blanks are simply cylinders. The bevel gear blanks were originally castings, but I fouled up on some dimensions and had to ditch the castings. The blanks shown were machined from continuously cast iron bar - lovely stuff to machine apart from the dust. The bevel pinions were machined with one cutter, a 4mm diameter ballnose. First a series of cylindrical roughing passes were done followed by a profiling pass with a fine stepover. The profiling pass is being machined in this picture, although the roughing passes can be seen:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Bevels_MEM_3.JPG)

The bevel gears do not need the 4th axis for machining as they are relatively flat:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Bevels_MEM_4.JPG)

The bevel gears needed several passes with different cutters. First roughing passes with a 4mm ballnose cutter, followed by a profiling pass with a 3mm ballnose cutter. Finally there was another profiling pass with a 2mm ballnose cutter to clear out the roots of each tooth. After several broken 2mm cutters I twigged that I needed to chamfer the inner edge of the bevel gear first, unlike the bevel pinions where it was done after machining the teeth. Here are two sets of finished bevel gears complete with bronze bearings where called for:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Bevels_MEM_5.JPG)

And finally all the parts for a complete differential:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Bevels_MEM_6.JPG)

For scale the ring spur gears are 10.833" and 11.833" OD. Note that the three pivots for the pinions (centre of picture) have a threaded hole in the end. That's so one can get the darn things out if disassembly is needed without having to resort to naughty words. In due course I'll write a few words on the differential centre and ring gears.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on March 07, 2016, 10:55:08 PM
Following on from my previous post here are a few notes on the differential centre and ring gears. The observant will note that the differential centre is painted red, or not, in some pictures. I forgot to take any pictures of the machining of the differential centres when I did mine. A while later I cut the pinion slots and cut the ring gears for a friend who is building the same engine. He had already protected his differential centre with red paint.

The turning of the differential centre and ring gears is straightforward faceplate work. I used the diddy 12" faceplate as this saves mucking about removing the gap piece and then replacing it correctly. Once machined the slots and holes that take the pins for the bevel pinions can be milled, drilled and reamed in the vertical mill using the dividing head. The paper towel stops the worst of the cast iron swarf getting into the 3-jaw chuck. Hidden behind the towel my dividing head has a handy reversible plate on the spindle with 56 and 60 slots. So this simple divide by 3 stuff can be done without faffing around with dividing plates:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Diff_MEM_1.JPG)

The slots into which the bevel pinions fit were cut using the rotary table. The rotary table is set up so that the T-slots are aligned with X and Y axes on the mill when the table reads zero. The DRO is set to zero at the centre of the rotary table. The differential centre is mounted central and such that one of the slots aligns with a T-slot on the rotary table. The four corners of each slot can then be co-ordinate 'drilled' using the milling cutter. The top and bottom of each slot can then be cleaned using the X axis on the mill table. The position and width of the slots are important as they control the engagement of the bevel pinions and gears. The sloped sides of the slots are machined by turning the rotary table 22 around each slot and then using the Y axis of the mill to join the holes in the corners, by eye. The sloping sides are for clearance only.

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Diff_MEM_2.JPG)

In theory cutting the two ring gears is simple - they're just spur gears. However, two practical problems arose. First, my dividing head has a 5" centre height and I needed 5.9". So I had to make some riser blocks from a lump of hot rolled steel. The blocks for the dividing head and tailstock were made as one and separated at the end to ensure that they aligned. Here is the slot for the dividing head being checked against a length of 5/8" gauge plate. The slot that holds keys for the table has already been machined and is being used to align the block during the machining of the second slot:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Diff_MEM_3.JPG)

When the blocks were split and machined to width two horizontal 'V's were stamped on the edge, so all I need to do is have the 'V's pointing at each other to ensure proper alignment. The second problem is more interesting. The ring gears have 63 and 69 teeth, neither of which is prime, but they cannot be cut using simple indexing with the standard division plates. Rather than mess about with gears for differential indexing I decided it was easier to make a special dividing plate with 63 and 69 holes. Very simple using the bolt circle function on the vertical mill DRO, if a little tedious. Just to be different the manufacturer of the dividing head chose to make the three countersinks in the centre of the plate 60 rather than 90. I used a large centre drill to create the countersinks:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Diff_MEM_4.JPG)

Finally the gear cutting:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Diff_MEM_5.JPG)

Note the special green clamp! In an ideal world the cutting forces from the involute cutter should create no torque on the gear. I cut all the small spur gears for the engine with no problems. However, on the first 69 tooth gear the cutter didn't cleanly enter the first tooth once I'd been round once - it was about 15 thou out. I spent ages checking and re-checking the maths and the indexing. This showed that only the last few teeth were out, so near the end the darn gear must have slipped slightly. Although it couldn't be seen it annoyed me, so I scrapped the gear, bought another casting and did it all again. This time the green clamp holds the blank against a small angle plate bolted to the mill table for each cut. You live and learn, and the wallet suffers in silence.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Kim on March 08, 2016, 03:13:18 AM
Nice gear cutting Andrew!  And I love the special green clamp :)
Kim
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on March 08, 2016, 01:28:09 PM
Kim: The green clamps, called crab clamps I think, are really great. Here they are in use this weekend assisting in the welding of laser cut quadrants to make the T-rings for the traction engine rear wheels:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Quadrants.JPG)

I bought them through 'Model Engineer' some time in the late 1980s. I recall there being some problem with delivery. Being a fully paid up member of the awkward squad I regularly rang the advertising manager at the publishers for about a year, until she decided it was easier to get the problem sorted, as I wasn't going to go away otherwise.

The 6DP involute cutter for the ring gears was the only one I bought new. I ended up buying from Victornet (?) in New York. Of course it's an 'import' but at least it is 20PA. Although such cutters are available in the UK they all seem to be 14PA, but I'd already decided to use the more modern 20PA. All the other 6DP, and 5DP, cutters I needed, plus a few I didn't, were bought secondhand from the US via Ebay - bargain.  :ThumbsUp:

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on March 08, 2016, 08:12:03 PM
Looking good Andrew...............Terry
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on March 10, 2016, 10:29:09 AM
Looking good Andrew...............Terry

Thanks Terry.  :ThumbsUp:  Progress on the wheels is frustratingly slow. One problem being that it's not worth getting the welder out and everything set up for an hour or so, but finding several consecutive hours is an issue. If nothing else the gliding club membership is finally coming out of hibernation and I'm getting lots of requests to review and sign off the ARC (Airworthiness Review Certificate) for assorted gliders. It takes quite a few hours for each review. The ARC is a legal document certifying that the glider is airworthy and hence fit to fly. So one doesn't want to make a boo-boo!

In the meantime here's a completely OTT use of the green clamps to hold the connecting rod tapered lock to CNC machine the round/tapered section at the top:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Clamps_MEM.JPG)

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on April 21, 2016, 01:24:00 PM
This thread seems to be attracting a steadily increasing number of views, but no comments. I'm not sure if that's good or bad?

Anyway, here are a few more gears, specifically the crankshaft pinions and final drive pinions. Here is one set of pinions, along with the arbors for holding them during gear cutting. On the right are a couple of ground arbors to check the bore size.

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Pinions_MEM_1.JPG)

On the left is a gear vernier. When I first started cutting gears I did a roughing and finish pass with the cutter and checked the tooth width with the verniers. It turns out I was wasting my time. I now cut gears in one pass; all that two passes does is wear out the cutter. Likewise the gear verniers weren't much use. For non-precision gears like these it is fine to touch off the cutter on the OD and then move the mill by the theoretical depth of the tooth and commence cutting. You live and learn. Unless of course you do something really daft and get a Darwin award.  :facepalm:

The final drive pinions are 5DP in cast iron and are straightforward machining. The crankshaft pinions are 6DP in EN8. The horizontal mill cut the EN8 like it wasn't there:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Pinions_MEM_2.JPG)

The crankshaft pinions as shown thus far have been scrapped. When I made the first set I was ignorant about machining EN8 and didn't get a good finish, as can be seen. I was also concerned about the fit of the splines and made the bore 10 thou bigger than specified for clearance. Sometime later, with more experience, I machined another set of EN8 gears for a mate, and got a much better finish. So I remade mine, and also reduced the bore to the proper size. I found that the key to a good finish on EN8 is surface speed. The new sets of pinions were machined at 800-1200rpm, using insert tooling.

Once I'd made the crankshaft thoughts turned to cutting the internal splines in the pinions. I wanted them to look neat, so I puzzled about how to get the correct radius on the end of the tool to be used in the slotting head. Eventually I twigged that I could use the cylindrical grinder to grind a diameter that I could measure, and then cut the toolbit in half and grind the reliefs by hand:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Pinions_MEM_3.JPG)

Here is a rather poor picture of the slotting in progress on a scrap blank (I cut the gear selector slot in the wrong place) as a trial. The pinion is mounted centrally on a rotary table. Relatively fine cuts were needed or the Bridgeport slotting head jammed:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Pinions_MEM_4.JPG)

The pinions required some work with needle files to achieve a good fit on the crankshaft splines. Not least because the width of the crankshaft splines vary by a thou or two over their length, but that's another story.  :'( Finally here are the proper set of crankshaft pinions in place and one of the final drive pinions just visible at the bottom of the picture:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Pinions_MEM_5.JPG)

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Steamer5 on April 21, 2016, 02:03:57 PM
Andrew,
 Don't worry about the lack of comments, just keep the updates coming ...PLEASE !! It's just gob smacking work, would be nice to sit & watch the work on the cutting of the gears.

Cheers Kerrin
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: steamer on April 21, 2016, 02:36:39 PM
This thread seems to be attracting a steadily increasing number of views, but no comments. I'm not sure if that's good or bad?

Anyway, here are a few more gears, specifically the crankshaft pinions and final drive pinions. Here is one set of pinions, along with the arbors for holding them during gear cutting. On the right are a couple of ground arbors to check the bore size.

(http://i1045.photobucket.com/albums/b455/jadge/Pinions_MEM_1_zps2kgwmv95.jpg)

On the left is a gear vernier. When I first started cutting gears I did a roughing and finish pass with the cutter and checked the tooth width with the verniers. It turns out I was wasting my time. I now cut gears in one pass; all that two passes does is wear out the cutter. Likewise the gear verniers weren't much use. For non-precision gears like these it is fine to touch off the cutter on the OD and then move the mill by the theoretical depth of the tooth and commence cutting. You live and learn. Unless of course you do something really daft and get a Darwin award.  :facepalm:

The final drive pinions are 5DP in cast iron and are straightforward mchining. The crankshaft pinions are 6DP in EN8. The horizontal mill cut the EN8 like it wasn't there:

(http://i1045.photobucket.com/albums/b455/jadge/Pinions_MEM_2_zpsmztsh8dy.jpg)

The crankshaft pinions as shown thus far have been scrapped. When I made the first set I was ignorant about machining EN8 and didn't get a good finish, as can be seen. I was also concerned about the fit of the splines and made the bore 10 thou bigger than specified for clearance. Sometime later, with more experience, I machined another set of EN8 gears for a mate, and got a much better finish. So I remade mine, and also reduced the bore to the proper size. I found that the key to a good finish on EN8 is surface speed. The new sets of pinions were machined at 800-1200rpm, using insert tooling.

Once I'd made the crankshaft thoughts turned to cutting the internal splines in the pinions. I wanted them to look neat, so I puzzled about how to get the correct radius on the end of the tool to be used in the slotting head. Eventually I twigged that I could use the cylindrical grinder to grind a diameter that I could measure, and then cut the toolbit in half and grind the reliefs by hand:

(http://i1045.photobucket.com/albums/b455/jadge/Pinions_MEM_3_zps0mghzuw2.jpg)

Here is a rather poor picture of the slotting in progress on a scrap blank (I cut the gear selector slot in the wrong place) as a trial. The pinion is mounted centrally on a rotary table. Relatively fine cuts were needed or the Bridgeport slotting head jammed:

(http://i1045.photobucket.com/albums/b455/jadge/Pinions_MEM_4_zpsiunnx7hg.jpg)

The pinions required some work with needle files to achieve a good fit on the crankshaft splines. Not least because the width of the crankshaft splines vary by a thou or two over their length, but that's another story.  :'( Finally here are the proper set of crankshaft pinions in place and one of the final drive pinions just visible at the bottom of the picture:

(http://i1045.photobucket.com/albums/b455/jadge/Pinions_MEM_5_zpslmnr0hto.jpg)

Andrew

Jadge.....just too much going on, on my end.....please proceed!   I'm watchin...

Dave
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jasonb on April 21, 2016, 04:04:53 PM
Quote
Likewise the gear verniers weren't much use. For non-precision gears like these

Andrew is that because we use involute cutters that will cover a range of tooth numbers, do the verniers only work with gears cut on a proper machine with a true form?

What sort of feed does the slotting head need, I did mine the hard way planing in on the lathe and 0.001" per pass was all I wanted to lhe the lathe cope with, at least the Fowlers are flat topped.

Looking good, I hope the start of the flying season won't slow progress too much.

J
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Kim on April 22, 2016, 06:04:49 AM
Hi Andrew,
I'm following along and enjoying watching your build, and learning!  Not a lot of comments from me, cause I don't have much to add.  But you're work looks beautiful to me!
Thanks for sharing!
Kim
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on April 22, 2016, 10:37:39 AM
Thanks for the comments; I'm not planning to stop posting, just curious as to why no comments.

Jason: Not so much the flying getting in the way at the moment as airworthiness reviews (sort of like an MOT). I've done 9 so far this year and at least two more to go, excluding getting some-one else to sign the ARC for my aircraft.

If I recall correctly the slotting head was happy with about 4 thou per stroke for a 5/16" slot. With narrower keyways it's happy with higher feeds.

As I understand it gear verniers measure the chordal thickness at the chordal addendum. The addendum and the tooth thickness across an arc of the PCD depend only on the diametric pitch. But the gear verniers can only measure linear dimensions, so both the chordal addendum and chordal thickness change slightly according to the number of teeth. For the 20 tooth 5DP pinion the difference between addendum and chordal addendum is about 6 thou, and between tooth thickness and chordal thickness less than a thou. Even allowing for the corrections the parameters we are interested in measuring do not depend on the shape of the involute away from the pitch circle. And therefore should not be affected by the fact that the form of an involute gear cutter is theoretically correct only for the lowest tooth count of the range of a given cutter.

The difficulties I had were mainly practical. If the gear vernier isn't exactly vertical over the tooth, and isn't exactly perpendicular to the gear axis you get false (over) readings. It became apparent that I was chasing my tail with the measurements and wasting time doing further cuts for no benefit. The price of a new 456A Starrett gear vernier is $1473. I'm glad I only paid around 20 for mine on Ebay!

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on May 07, 2016, 11:59:58 PM
Having recently described the gears, including the crankshaft pinions, it seems logical to have a look at the machining of the crankshaft. The cast crankshaft comes with two integral lugs to allow turning of the crankpin. The first operation was to drill two centres at each end at the correct spacing for the throw. I used the vertical mill and DRO to ensure accuracy, and used the mill right-angle attachment for the first time:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Crankshaft_MEM_1.JPG)

With the crankshaft mounted between centres on the lathe the crankpin was machined using a insert parting tool sticking a long way out of the holder. A series of plunge cuts were made and once the rough cast surface had been removed the parting tool was used to take shallow cuts sideways to reach the correct diameter:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Crankshaft_MEM_2.JPG)

Once the crankpin was machined the crankshaft is located between centres on the second set of centres and the main shaft rough machined. Then a fixed steady is used to machine the shaft to length and a new centre drilled. Finally the shaft is machined to size:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Crankshaft_MEM_3.JPG)

For the second half of the shaft the previously machined feature can be held in the collet chuck. I had a lot of chatter problems when machining the main crankshaft. The only solution seemed be fairly aggressive feedrates. The chatter was probably partly due to the fact that I chose not to use jacks to increase the stiffness of the crankshaft. I've only had severe chatter problems once before, when machining the front axle. That was SG iron too, so I wonder if it a characteristic of the material? Poor damping possibly? I am sorry to say that one of the crankshaft journals for the eccentrics has ended up undersize.  :embarassed:

The final part of machining the crankshaft is the splines for the drive pinions. The standard way of machining these is to use a dividing head on the vertical mill and an offset cutter to produce the sides of each spline. The waste material between the splines is then removed by a series of cuts, rotating the crankshaft a small amount each time. Alternatively the splines can be created by milling slots and then fitting keys to mimic the splines. I didn't feel that either of these methods was ideal. It is possible to buy commercial spline cutters that create the gap between the splines, in a similar fashion to involute gear cutters. However, no commercial cutter was available for the size of spline I needed. So I decided to make my own cutter.  :ThumbsUp:  The cutter was modelled in 3D CAD, with relief, and machined on my 4 axis CNC mill from gauge plate. The roughing cuts were parallel to the axis of rotation of the cutter, and the finishing cuts were perpendicular to the rotation axis. Here the roughing cuts have been finished and the final cut is in progress:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Crankshaft_MEM_4.JPG)

There is a compromise between the stepover distance for the finishing cut and machining time. In this picture of the finished cutter (before the drive key slot was machined and before hardening) the finish cut stepover can be clearly seen. However, some gentle draw filing with a needle file removed the high spots:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Crankshaft_MEM_5.JPG)

After hardening and tempering the cutter was used to cut the splines on the horizontal mill:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Crankshaft_MEM_6.JPG)

I am embarrassed to say that the width of the splines varies by a couple of thou over their length, probably because I didn't take care to ensure that the tailstock was exactly on centre height. Fortunately the mating pinion gears only travel a short distance on the splines. So the final filing to ensure a snug fit of the pinion gears can be tailored for the postion of the gears on the splines. And you'd never know looking at it.  ;)

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: yogi on May 08, 2016, 02:04:08 AM
Fantastic work Andrew!  :ThumbsUp:
That spline cutter turned out beautiful.
Thank you for sharing your techniques.  :cheers:
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on May 10, 2016, 06:48:37 PM
Hi Yogi,

Thanks for the compliment. As well as the spline cutter I've had a go at making some square thread taps and a hob for free hobbing a worm wheel. Generally I've been pretty pleased with the way all the cutters have turned out, and the job they've done.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Mcgyver on May 10, 2016, 07:04:34 PM
very nice work on challenging parts, thanks for posting it
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: zeeprogrammer on May 11, 2016, 01:11:48 AM
I hadn't seen a right-angle attachment before. Not that I remember anyway. That's cool.

But the cutter is awesome. Just as awesome as making a part, no?
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on May 11, 2016, 11:27:49 AM
Zeeprogrammer: Agreed; if anything making the cutter was more interesting than cutting the splines, especially as I hadn't made this sort of cutter before.

The right-angle attachment (Bridgeport No. 3 I think) also comes with a arbor and a support bracket that fits on the Bridgeport ram, so it can be used for horizontal milling. I have used it in this mode, but a caveat is that it is only suitable for light milling. For heavy milling I use my horizontal mill, which makes the Bridgeport look lightweight.

Somewhere I've also got a Quillmaster for the Bridgeport which comes with it's own dinky right-angle attachment, but as yet I haven't used it.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on May 14, 2016, 10:53:14 AM
FOr the idly curious this is the Quillmaster and dinky right-angle accessory that fits on it:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Quillmaster_MEM.JPG)

I call it chicken and egg tooling. If you haven't got one you never consider designing a part that may need it. On t'other hand if you do have one you never seem to have a need for it.

Speaking of Bridgeports mine clunked more than usual yesterday afternoon and then the spindle coasted to a stop. It happened just after I'd countersunk the wrong hole. Turns out it was the varispeed drive belt that had broken. I've changed this before so it only took me an hour or so to change this time. The manual isn't a whole load of help. When removing the motor it talks about using some screws from a cover plate to hold the drive cones apart before removing the motor and belt. Of course this don't work if the belt is broken.  :'(  Once I wrestled the motor out and got in on the mill table, without dropping it or falling off the ladder, I used the trick I eventually worked out last time. You hammer the old drive belt into the cones and this prises them apart enough to get the screws in place. The belt doesn't damage the cones, and the cone angle, and friction, is such that it doesn't ping out. The new drive belt seems quieter than the old one, so I hope it will last a bit longer.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on May 29, 2016, 11:38:28 AM
You have certainly got some nice equipment there Andrew,  I'd love to do my own gearcutting.       Nice gliding weather this weekend?
Best Wishes,          Terry
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on May 29, 2016, 08:48:19 PM
You have certainly got some nice equipment there Andrew.............

That's because I suffer from OIS - old iron syndrome. I just can't stop buying it.  :embarassed:

Not great gliding this weekend. I was tug pilot yesterday afternoon. After a lot of low cloud in the morning I eventually did a couple of tows late afternoon. They were both passenger flights and wanted to get to 3000ft. I declined to climb above cloud, as the blue gaps were too small, the visibility was very poor, and there is a large American Airshow at Duxford this weekend. The exclusion zone is only a few miles from us; I'd look a right wally if I got lost above cloud and infringed the zone. I got to 2700 feet on the first tow before deciding it was time for the glider to go, as I couldn't tell what was cloud and what was just haze. On the second, later, tow we got to 3000 feet in the murk, but below cloud.

Today was similar, low cloud all morning, breaking up mid-afternoon. I'll probably work tomorrow, despite it being a public holiday. I really want to do more grinding and welding of the T-rings on my rear wheels, but I don't suppose the neighbours will appreciate some idiot spending hours angle grinding on a Bank holiday.  :ThumbsDown:  So I'll work tomorrow and take a day off later in the week to do the wheels while everyone else is out at work.

Andrew

Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on May 30, 2016, 10:32:08 AM
You are right Andrew, neighbours and angle grinders do not mix.               Terry
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on May 30, 2016, 05:06:11 PM
Tug pilot, glider "MOT" person,    do you ever get the chance to fly your own?
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on June 01, 2016, 11:00:38 AM
Tug pilot, glider "MOT" person,    do you ever get the chance to fly your own?

Not as often as I'd like. I haven't flown my small glider at the local club this year, although I have done a few flights in the big glider. So far this year the weather has been poor too. It seems to be mostly low cloud and murk. I am trying to take one day off each week to either fly a glider or work on the traction engines.  :ThumbsUp:

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on July 13, 2016, 08:53:44 PM
As an antidote to gears I've finished the water pumps, and delivered the third one to my mate in return for folding drinking vouchers. Here is one pump assembled and all the parts for the second:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Water_Pump_MEM_1.JPG)

All the parts for the pumps, including nuts, bolts, studs and washers, apart from the 4BA nut (upper centre) are home made. The two wing valves (centre) were machined from glass filled PTFE, which machined beautifully, unlike pure PTFE which is 'orrid stuff to machine and hold tolerances on. The spacer (bottom right) is a fancy shape just for the hell of it, and because it's easy on a CNC mill.

The key to machining the main casting was an 'angle plate' drilled and tapped for the casting and made from aluminium extrusion, plus a steel spacer block which eventually became the fancy shaped spacer. Here are some examples of the angle plate and block in use. The first operation is to drill, ream and bore the ram bore and gland recess:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Water_Pump_MEM_2.JPG)

In a different orientation to drill, ream and screwcut the overflow valve spigot:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Water_Pump_MEM_3.JPG)

And the last operation machining and threading the outlet spigot. This was the only thread on the casting cut with a die. The 3/8" BSP die was held in the tailstock with special home made die holder that was thin enough to pass between the outlet spigot and the bolt down spigots:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Water_Pump_MEM_4.JPG)

Not only was the aluminium angle plate multi-purpose for the water pump casting it was original made and drilled for holding the main gear change casting. Pretty good for an offcut acquired from the scrap bin of my commercial aluminium supplier.  :ThumbsUp:

Finally here is the water pump in place on the hornplates:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Water_Pump_MEM_6.JPG)

I have also been busy making the eccentric straps and sheaves. So once I've made the water pump eccentric rod I can connect everything up and see if it goes round. And, more to the point, see if my 3D CAD model is correct and that the few thou of clearance between the eccentric rod and ram is positive.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Dave Otto on July 14, 2016, 01:55:16 AM
Nice work on the pumps and also interesting face plate work.
Folding drinking vouchers  :lolb:  I like that!

Dave
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on July 15, 2016, 11:05:24 AM
Thanks Dave, I like drinking vouchers too!

It took quite a while getting the faceplates set up. The ideal would be to do it on the flat and then lift the whole caboodle onto the spindle. But I've done myself a mischief in the past doing that, so it had to be set up in situ. Careful examination of the pictures will show that two faceplates are involved. The first set up uses the large (18") faceplate and involves removing the gap piece, which is a PITA. Or, to be precise, removing it is easy, it's the putting back and ensuring that the lathe still turns parallel that is a PITA. The other two set ups use the small (12") which doesn't need the gap piece removed.

As an aside here is a valve body, and the home made cutter used to undercut the seat for the inlet wing valve:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Water_Pump_MEM_7.JPG)

Note that this particular valve body is scrap due to a foul up when screwcutting the 3/8" BSP thread at the left end.  :embarassed:

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Chipswitheverything on July 15, 2016, 12:07:18 PM
Hi Andrew, when I saw the photos of the face-plate set ups I thought that they must have been mostly done on the bench and then transferred to the lathe, but now that you say  they were done in situ, it must have taken enormous patience and dexterity!  If ever having more than two hands would have been useful....

Cheers, Dave
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on July 15, 2016, 09:25:41 PM
Dave: It's a big faceplate, 18" diameter. I've just weighed it, and the result was 23kg. So with the angle plate and clamps and casting probably nearer 30kg. That's a lot of weight to lift at chest height, and arms length, while trying to get the camlock pins lined up. When I did myself a mischief I had the flywheel casting on the faceplate. The faceplate plus machined flywheel weighs 33kg, so probably nearer 40kg with clamps and an unmachined flywheel. I should have known better, and paid the price. The trick to setting up in situ is to tighten the clamps enough to stop the whole falling apart but not so tight it doesn't move when tapped with a mallet. It's a trick I haven't mastered yet. The most important lesson is go and have a cup of tea if it isn't going right, before one gets cross and breaks something.  :'(

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: yogi on July 16, 2016, 08:48:54 AM
Very impressive work you are doing Andrew!  :ThumbsUp: :ThumbsUp: :ThumbsUp:
The water pumps are fantastic! Thanks for the update.  :cheers:
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on July 23, 2016, 02:11:24 PM
Excellent work as usual Andrew.           Terry
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 02, 2016, 10:09:56 PM
Having previously mentioned a mischief here's the part that caused it, the engine flywheels. The final OD is a bit over 16" and the rim is 2" wide. The initial castings were quite rough with a lot of flash and a slight mismatch between the two halves during casting, resulting in a lot of metal on the inside of the rim needing to be removed to give a reasonable surface. Having started with a file I quickly reverted to angle grinders, flap wheels and the coarsest bastard files I could find. Even so it took many hours to clean up the castings. The final task before machining was to slather the castings with U-Pol and then sand most of it off again.

To simplify setting up the castings on the large faceplate I did it with faceplate resting on a wooden board on the lathe bed and then lifted the whole assembly onto the spindle. That's when I did the mischief. It was a very odd, rather unpleasant sensation. A bit like cramp in my arms, but without the intense pain. I couldn't move my arms properly, like a sort of paralysis with commands being sent but not being obeyed.  :(

Here is the casting on the faceplate, on the spindle:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Flywheel_Setup_MEM.JPG)

It is normally regarded as a bad thing to clamp flywheels using the spokes, as they can get broken. However a close look will show four steel pillars bolted to the faceplate. Two of these are in the junction of a spoke and the rim. These provide the drive from the faceplate to the casting. The other two pillars are on the inside of the rim and locate the flywheel radially. So all the clamps are doing is stopping the casting falling off the faceplate. They're not providing the drivng force, so don't need to be done up tight.

Although the casting was a bit rough it machined beautifully, with no hard spots or inclusions. There was a lot of metal to take off the width and diameter of the rim. Here are some chips flying:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Chips_Flying_MEM.JPG)

Note the lefthand boring bar in the 'wrong' side of the toolpost in order to reach the outside of the rim. Machining was done at the slowest speed of 40rpm, which equates to about 170fpm. For roughing DOC was 40 thou and feed 10 thou/rev.

I had intended to use the hydraulic copy unit to machine the crowning on the rim. But no way no how could I get the tool anywhere close to the right place. So I reverted to the method of machining two tapers at 2.5 and 5 on both sides and then blending with files and wet 'n' dry. The crowning is possibly rather more noticable than scale. It took a lot of filing and polishing so I wanted to make darn sure that the rivet counters noticed it!

The finished flywheels are shown in situ in the first photo in the first post of this thread.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Chipswitheverything on August 02, 2016, 10:40:09 PM
Monumental work, Andrew, and great to see the photos of this very considerable engine build.  Looked back at your first pics of the two engines part assembled, you have tackled some huge and daunting componentry in this project.   But I do wince a bit when you mention self-inflicted semi paralysis  , no one should suffer to quite that extent for their model engineering!  Could you perhaps rig up some sort of ceiling beam and mini electric hoist above the lathe spindle? or maybe adapt a Machine Mart type of cheap engine crane to assist with chucks and workpieces?
Dave
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jo on August 03, 2016, 08:14:37 AM
 :o that is a bit big to lift with the faceplate.

One of the reasons (the second time around) I decided to make a 2" model is that the parts are more manageable but I do find some of the tooling must have put on weight over the years  :-\

I see you needed to take the gap out  :facepalm: I am still hopeful that I will be able to get my ploughing drum on the face plate to turn without having to remove the gap piece

Jo
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 03, 2016, 10:47:30 PM
Thanks Dave! There's no room for an engine crane of any sort in the workshop, not even folded. Even the smaller machine tools are spreading into the hallway. But I have a longer term plan to fit some rails and a chain hoist over some of the machines. Some of the accessories like the capstan unit for the lathe, and dividing head and vertical head for the milling machines are pretty heavy, 50+kg, and they're on the limit of what I can lift. That's only going to get worse as time progresses. Eventually I'll need some mechanical assistance.

Taking the gap piece out is simple. Putting it back so the lathe still turns parallel is a lot more of a pain! When I first got the lathe I spent months bolting it down, adjusting the bolts and checking with an engineers level in an attempt to get the lathe turning parallel to better than 4 thou over a few inches at the headstock. Nothing worked. It was only when I turned the front axle journals a good 25" inches from the headstock that I fell in. The journals turned parallel to better than I could measure. So I wondered about the gap piece. I took it out and was scrupulous about cleaning it and the sequence of replacing it; low and behold I was turning parallel to within tenths at the headstock. You live and learn, although at the rate I'm going I'll be dead before I learn much more.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: mal webber on August 03, 2016, 11:40:10 PM
Hi Andrew really impressive work your doing , enjoying your thread and learning  the way you do your set ups ,I have  gap bed on my lathe nothing as big as yours  just a student 6", had trouble setting the lathe after refitting gap then i watched Keith fenner on youtube setting it up with a dti ,easy when your shown how.

Mal.
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 05, 2016, 12:12:14 PM
Mal: Thanks, I'm glad the descriptions have been of some use.

I'm not sure about using a DTI to set the gap piece? If it is refitted correctly I expect it go back accurately without the need for measurement. For my gap piece the procedure is to lightly fit the holding down bolts, making sure everything is clinically clean. Then fit the tapered alignment pin, tighten the small screw that pushes against the headstock, and finally tighten the hold down bolts. Of course the hole for the tapered pin is critical but this is machined by the manufacturer. I may be asking too much to expect the gap piece to be accurately replaceable, but it does seem to be the case on my lathe. However, I have a friend with a similar size far eastern lathe, and if I recall correctly the instructions basically say you're on your own once you've removed the gap piece.  :'(

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on August 05, 2016, 05:50:27 PM
Andrew!     You do surprise me.......all that equipment and you have to risk becoming a soprano when you lift stuff :facepalm:  I don't have much machinery, not much room either, but I DO have an engine crane. I'm 70 this year and and could not operate without it. I can JUST manage a back wheel onto the bench but it leaves me knackered.  The main snag with engine cranes is finding room under benches, etc for the outriggers.
Please take care.......I'm sure we all want to see your build continue with you in good health.
Best Wishes         Terry
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 06, 2016, 10:28:35 AM
Terry: There's absolutely no way I can get an engine crane into the workshop. At the moment I just have to think ahead and make sensible lifts, ensuring that the landing place is all set up in advance. However, I am already coming apart at the seams, and I'm not 60 yet,  so I know that in the future I will need assistance. I'm not too worried about squeaky voices; I already have a problem in that area. :embarassed: When I saw the consultant he put me off having the operation until it was absolutely necessary.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jasonb on August 06, 2016, 01:17:17 PM
Andrew as you have no floor space for a crane think about an overhead beam with a beam trolly or a swing out arm for a "barrow hoist" located near the lathe and one gor the mill. I assume you have a bit of wall or ceiling space but that could be wishful thinking on my part :-\

I picked up a hosit and swing out are from Lidl a while ago for not much but have not got round to fixing it yet.
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jo on August 06, 2016, 01:33:30 PM
This is what Tgs has set up above his head. The wheels allow for sufficient movement to take Tgs heads or castings clear of the front of the bed and down onto the roller skate to move them off to their storage location.

My supplier has the advantage of rafters so he just hangs his off a length of scaf poles which span 4 joist.

Jo
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 08, 2016, 11:22:45 AM
Andrew as you have no floor space for a crane think about an overhead beam with a beam trolly or a swing out arm for a "barrow hoist" located near the lathe and one gor the mill. I assume you have a bit of wall or ceiling space but that could be wishful thinking on my part :-\

Almost no wall space, and not much ceiling space! I am planning a double rail attached to the ceiling joists that will allow me to run a manual hoist. The intention is to cover the centre lathe and all three milling machines, as they're the machines that have the heaviest accessories. I'll probably include some support pillars, as the joists are not that large.

Some while ago I had a look at the 'crane' that John Stevenson added to his Bridgeport. If extended it could cover all the machines, but would be a PITA when I wanted to swivel the Bridgeport ram, as I have operational heads on both ends.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 20, 2016, 11:11:26 PM
The final drive gears are the last gears to be made for the engines, apart from the governor bevel gears, which are designed but not yet machined. As is the norm with me the final drive gears have been a bit of a drawn out saga. I started machining the castings some years ago. The OD is 14.8" so they were bolted onto the large faceplate:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Final_Drive_MEM_1.JPG)

After machining the first casting I discovered I had some runout, up to 20 thou, on the OD, side to side, radially it was fine. :embarassed: At this point I gave up and moved onto summat else. After I had machined the flywheel some while later it sank in that I must have distorted the casting when bolting it down to the faceplate. So I changed the way I clamped, and drove, the castings and then carried on regardless (English joke):

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Final_Drive_MEM_2.JPG)

After tidying up the part machined casting and machining the remainder the maximum runout was 4 thou or less - much more acceptable. One needs to keep in mind that on the full size engines these gears were often 'as cast', gear teeth and all. There was no way no how I could get the gear blanks on the dividing head and under the arbor/cutter on the horizontal mill in the normal manner. I considered 'overcutting' where the gear sits above the arbor and cutter, with the outboard end of the arbor supported by a special support down to the mill knee. However, this wouild have required a considerable amount of hardware to be made, not least some large riser blocks for the dividing head. So in the end sense prevailed and I decided to cut the gears horizontally, using the rotary table rather than the dividing head:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Final_Drive_MEM_3.JPG)

Fortunately the gears have 72 teeth so each index is exactly 5, making the indexing easier. Note the spotlight in the picture shining on the rotary table scale. A disadvantage of the method is that the mill table and knee need to be raised and lowered, by hand, to cut each tooth. I found I could do about a third of a gear at a time before needing tea. It keeps yer fit if nothing else. The teeth are cut full depth in one pass, and although not obvious there is support under the casting near the cutter. Here are the four final drive gears, and winding drums:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Final_Drive_MEM_4.JPG)

I actually cut the teeth on six gears, as my mate just 'happened' to have his gear blanks machined and ready at the same time.  ;)

Andrew

Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: crueby on August 20, 2016, 11:46:00 PM
Very nice! Those gears are beautiful monsters! Bet you could build a nice tower clock movement...

 :popcorn:
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Kim on August 21, 2016, 12:52:50 AM
Your gears look great, Andrew!  Cutting six 72 tooth gears of that size, by raising and lowering the knee, that's a lot of work!  You must be exhausted!

I'm doing some gears right now too, but they are MUCH smaller :)

Kim
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jo on August 21, 2016, 07:47:02 AM
A disadvantage of the method is that the mill table and knee need to be raised and lowered, by hand, to cut each tooth. I found I could do about a third of a gear at a time before needing tea. It keeps yer fit if nothing else.

 :Lol: Yes I found with "H" winding the knee up and down makes my arm ache after a while. Which is why when I went looking for my "bigger mill" to make my Steam Plough on I made sure it came with a powered knee  :cartwheel:

I'll have to be careful of these friends just happening to have gears ready for cutting as I get to that stage. I can see someone wanting to visit to have his winding drum gear cut. Assuming he has worked out how to turn it on his Chinese lathe by then :mischief:

Jo
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on August 21, 2016, 09:37:38 AM
Nice work Andrew      :ThumbsUp:                Terry
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Steamer5 on August 21, 2016, 02:11:29 PM
Hi Andrew,
 I got worn out just thinking about how much handle winding you had to do to cut those gears! Well done! Who needs to waste time at the gym when you have a project like this on!

Oh by the way just watched Carry on up the Khyber, they are playing one a week, I'd forgotten how funny there are! (Must be my bent sense of humour!)

Cheers Kerrin
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 23, 2016, 08:47:25 PM
Thanks for the kind words. The answer is 432 cycles, plus a few to check that the cutter passed cleanly through the first gap cut, so as to double check the indexing. Just listening to the noise, or lack of it, my impression is that the rotary table is tad more precise than the dividing head after going round once.

It's good that a least one person got the joke. Some of the Carry On films have dated a bit, but 'Carry on up the Kyhber' is still well worth watching. Of course one wouldn't be allowed to make such films these days.  ::)

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on September 03, 2016, 11:25:32 PM
I have previously shown shown a picture of the hollow pistons for my traction engines, but I hope I haven't described them before in this thread, or I'm going to look a right Rodney.

Full size engines had hollow cast pistons to save weight thus reducing the reciprocating forces on the connecting rod, bearings and crankshaft. In 4" scale the norm is to use aluminium pistons rather than cast iron to save weight. However, aluminium has a larger coefficient of thermal expansion than cast iron. To allow for this the piston is made undersize, if I recall correctly the allowance is 4 thou per inch of cylinder diameter. For my LP piston which is ~3" diameter that is 12 thou, otherwise known as a rattling good fit. I wondered if it would be possible to make hollow cast iron pistons, as two halves screwed together. Some playing in 3D CAD showed it was possible. The hollow cast iron HP piston would weigh about the same as the solid aluminium piston, but the hollow LP piston would be somewhat lighter. Here is a section of the two parts of the LP piston:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Hollow_Pistons_1_MEM.jpg)

It seems sensible to check and see whether the hollow pistons would survive the boiler pressure. Now of course in reality the pressure in the cylinder is going to be lower than boiler pressure due to losses in the passages and possibly wire drawing in the ports. However, I chose to use full boiler pressure (170psi) for both cylinders. That may seem strange for a compound, but I am planning to fit a simpling valve, as per full size, which allows boiler pressure steam to be applied to both HP and LP cylinders for extra ooomph. For the LP piston here are the deflections under 170psi, derived from a FEA add-on package to my 3D CAD:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Hollow_Pistons_2_MEM.JPG)

And here are the stresses, all comfortably below the strength of the cast iron (GR17). Note that the central boss is filleted, this is to reduce the stresses due to a sharp change of section:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Hollow_Pistons_3_MEM.JPG)

Having modelled the pistons it seemed sensible to 3D print them to get a look and feel. Note that these were printed before I altered the boss of the LP piston to a fillet (piston top left):

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Hollow_Pistons_4_MEM.JPG)

Turning the piston halves is straightforward, if a little tedious. Here are all the tools used for both halves:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Hollow_Pistons_5_MEM.JPG)

This picture shows cutting the thread that holds the two halves of each piston together. Since my lathe is imperial I chose to use a Whitworth form 32tpi thread. After cutting reliefs there are about three pitches on the thread. The internal thread halves were made first, and these were used a gauge to check the external threads. Before each fitting care was taken to brush the thread with a fine brush to remove cast iron dust, otherwise one gets a false impression of the fit:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Hollow_Pistons_6_MEM.JPG)

The final operation on each half was to nearly part off, the final cut being made with a hacksaw. The piston ring grooves are exactly to width and depth for the Clupet piston rings I have decided to use. However, the OD of the pistons are left approximately 15 thou oversize. The completed pistons will be ground to final size once I have made and fitted the liners:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Hollow_Pistons_7_MEM.JPG)

Once the halves of the pistons are made they can be screwed together and mounted on an expanding mandrel in the collet chuck to bring the piston to the correct width and to machine the recess for the piston rod nut. Hollowing out the internals of the pistons and forming the ribs was a simple operation on the CNC mill. A 6mm cutter was used for bulk material removal and a 4mm cutter for forming the ribs:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Hollow_Pistons_8_MEM.JPG)

Finally here are the finished piston halves, piston rods and nuts:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Hollow_Pistons_9_MEM.JPG)

The piston rods and nuts are made from 303 stainless steel. My experience of 303 stainless is that it is easy -peasy, and that was true for the nuts, simple to get an excellent finish. The opposite was true for the rods, they turned like a complete pig. So much so that I went back and checked my invoice from the commercial steel stockist to make sure I'd got the right material. You never know with commercial metal stockists. As well as the traction engine material I buy quite a lot of metal and plastic for work. I can safely say that commercial metal stockists are hopeless. I've had the wrong size delivered, metric when I've ordered imperial, and vice versa. I'm always amazed when the complete order is actually on the lorry all at the same time. And on the last aluminium order they missed off a 6 metre length of angle. When it was delivered the next day it resembled a banana having a bad day. I took it anyway, but insisted on a credit note.

Back to the 303 stainless; after some experimentation I found that slowish sfm, with coolant, gave an acceptable, but not great. finish. Oddly enough screwcutting the 32tpi thread was absolutely no problem.

Of course, when the engines are finally assembled all this work will be lost to the outside world, but at least I will know what is there internally.

Andrew

Rodney = plonker - from the UK TV show 'Only Fools and Horses'
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Steamer5 on September 03, 2016, 11:37:41 PM
Hi Andrew,
 Oh goody, saw you article in M.E.(well I think it was yours) on making these, now will have to digest this.
No popcorn today, it's farther day here, so I requested Eccles cakes  : :P!  And they have just come out of the oven, so time for coffee too!

Cheers Kerrin
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: crueby on September 03, 2016, 11:46:12 PM
I've never seen hollow pistons before - thanks for the details, and great work!!
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: fumopuc on September 04, 2016, 06:51:48 AM
Hi Andrew, very interesting piston project. Impressive how you did the entire process, like in real job live.
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on September 04, 2016, 10:27:56 AM
Oh goody, saw you article in M.E.(well I think it was yours) on making these, now will have to digest this.

Correct, it was my article in Model Engineer, a couple of years ago if I remember correctly. I'm now in the process of writing up the design and manufacture of the water pump for ME.

Ah, Eccles cakes, mmmmm. It hadn't occurred to me to heat them? I'll have to try that next time I buy some.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Steamer5 on September 04, 2016, 11:02:39 AM
Hi Andrew,
 At the time the Eccles cake were fresh out of the oven! Raewyns a very good cook!

It's going to be interesting to see how they preform, the reduced weight has got to be good & similar materials for the cylinder & piston can't be bad!

Cheers Kerrin
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: yogi on September 23, 2016, 12:34:26 AM
Excellent work Andrew!  :ThumbsUp: :ThumbsUp: :ThumbsUp:
I always enjoy seeing you techniques. Thanks for sharing!
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on September 30, 2016, 08:37:21 AM
Hi,  Andrew,      Re your oilers on TT I attach some pics of our 12" scale stuff.  1st pic is 1904 SCC roller, then a 1902 "Devonshire" SCC, and finally a1919 Gold Medal DCC.  The latter does a fair bit of road work, hence big oil pots.                   

Good work as usual.......................Regards             Terry
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on September 30, 2016, 09:22:46 PM
Thanks Terry, looks like I've been over-cautious putting a 1/32" hole in my oilers, compared to the holes in your pictures! I've also got my square head bolts fitted the wrong way round. :embarassed: Nor do I have a split pin, but locknut and split pin does seem a bit OTT. Particularly as they're not fitted properly. I wouldn't sign off a split pin like that on a glider; the legs should be bent round the shaft. Makes them a PITA to get out though.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on September 30, 2016, 09:59:29 PM
Hi,   The split pins are fitted that way for ease of removal in case some fettling is required on the road.  They do not lock the nuts but merely prevent them from dissapearing after you have heard the knocking and stopped to investigate.  The nuts will be loose but still on the stud!   I know that sounds odd but bearing caps sometimes need to be backed off on the move if it gets too warm.  If all is set up properly at the build / rebuild stage none of this should happen, but we are dealing with 100yr old iron here with unknown histories.

When I used to restore cars, etc. split pins were always bent right around as you describe. Horses for courses I suppose.

I've just started on all the studs for the cylinders :'(    I covet your "production" machinery.........I could be some time........

Regards               Terry
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on October 07, 2016, 07:05:34 PM
Terry: So if I understand it the split pins are a later addition rather than original fit?

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on October 07, 2016, 08:33:54 PM
It appears that I have posted some of the pictures included here elsewhere on the forum but not, I hope, in  this thread.

The steering gear drawings are rather sketchy. The OD of the worm is given along with a lead of 1" and pitch of 1/2", ie, two start. The worm wheel is stated as having 22 teeth and an OD is given, but no other information. The worm wheel is clearly a helical gear rather than a worm wheel. Starting with the worm I assessed the options for machining. My lathe gearbox  will cut a 2 tpi thread but not 1 tpi. I suspect that even 2 tpi would be pretty scary.  :o  Another option was to use the 4th axis on the CNC mill. In theory this is fairly simple, the code:

G01 X100 A720 F200

should advance 100mm in X at the same time as rotating 720, ie, two turns, around the A axis. The feedrate should be interpreted in mm/minute. Experiments with Mach3 showed that this was simply not the case for the feedrate. Then I discovered the 'radius compensation' option, which I though would compensate for changes of the diameter being machined. For the same numbers in the G-code the distance actually travelled increases as the diameter increases. Wrong again, experiments gave numbers that made no sense. Then I found some information on a forum implying that the radius compensation was for the axis of rotation being different to the axis of the machine. But in my case the axes are co-incident; if you set the value to zero it disables the function, so you need to set it to a small value, say 0.0001. :facepalm: After more experimentation I thought I'd come up with some feedrate numbers that were sensible.

It was now pointed out to me that a two start worm is not prototypical, and it will backdrive, in other words the worm wheel will drive the worm if torque is applied. Back to the drawing board. A worm wheel will backdrive if the tangent of the helix angle is greater than the coefficient of friction between the parts. That's the theory anyway, but is highly dependent upon surface finish, lubrication and the amount of vibration present. I changed the design to a single start worm with a lead and pitch of 0.5". Flushed with success I re-wrote the G-code.  I drew up the thread form 20 times size on graph paper and plotted the positions needed for roughing with a 6mm and then 4mm endmill, and finally a tapered endmill with an included angle of 30. Of course normal Acme threads are 29 included, but no cutter was available for that value, and since I am making both gears, it doesn't matter. Good luck to any rivet counter who spots it.  :) I then machined a trial worm in Delrin. It looked great, except that it was the wrong hand thread.  :'( Still, simple enough to change, just a minus sign in the G-code. Then I cut a couple of worms in steel. Oddly there was some chatter using the HSS tapered endmill and the finish wasn't as good as I expected. Slowly it dawned that the rotary axis hadn't slowed down for each successive tool as coded, it was just running flat out. Cue more experimentation.

After some hours of trials I contacted the manufacturer of my CNC mill. They said that Mach3 was bleep-bleep in this area and I should use G93, inverse time feedrate. This is an odd one. The time taken to execute the line of code is the inverse of the value given, in minutes. So a value of 1 will execute in 1 minute, but a value of 0.2 will take 5 minutes. More experiments showed that this worked, with a small but consistent time offset, a few seconds. Having sorted all these issues out I could then machine the real worms. Here's a general shot of the setup with a 6mm cutter taking its roughing cuts:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Steering_Worm__MEM_1~0.JPG)

And the finished worms with keyways cut:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Steering_Worm_MEM_2.JPG)

Having made the worms I moved onto the worm wheel. I wanted this to be single enveloping, ie, the worm wheel wraps partly around the worm. Normally these are cut using a hob with the blank geared to the rotation of the hob to produce the correct number of teeth. I don't have facilities for this, so I resorted to free hobbing. This is where the worm wheel is gashed with embryo teeth using a standard involute gear cutter and the hob is then used to clean out and form the teeth. Since the worm wheel has been pre-gashed the hob can drive the worm wheel itself, at least that's the theory. Making the hob was simple, just a longer version of the worm. Here is the embryo hob before the teeth were cut. Material was silver steel:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Steering_Worm_MEM_3.JPG)

The thread at the right is an odd one, 25mm OD and 20 tpi Whitworth to fit a Clarkson style milling chuck. As a precursor to machining the worm wheels from the supplied castings I made one in steel to test the process. This highlighted a number of areas where I needed to up my game. On the steel worm wheel I machined the curved throat on the OD by eye. This wasn't sufficient as there was some rubbing of the hob at maximum depth. For the proper worm wheels I filed a template from sheet steel and used this as a gauge to get a more accurate throat shape. To get the maximum depth I could gash the teeth to while allowing the hob to clean up I used CAD. I can't remember the value but it worked well. Except on the prototype steel worm wheel. I traced this to lack of care in centring the hob transversely, so it cut more on one side than the other. I took more care with the proper worm wheels. Of course I was keen to see if the technique worked or if the hob would disintegrate so I rushed the setup with the steel worm wheel. Starting the hobbing process is binary machining, you can't sneak up on using the hob, you just have to drop the clutch on the mill and stand back!

For gashing the worm wheel blank is set over by the helix angle of the worm, although it is not obvious in this picture:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Steering_Worm_MEM_4.JPG)

For hobbing the worm wheel blank is set back to be perpendicular to the hob. Here is a picture of the hobbing of the worm wheel, notice the significant difference in tooth shape:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Steering_Worm_MEM_5.JPG)

The material is cart iron so machining is done dry. After I had machined the steel worm wheel I noticed some faceting on the tooth faces. I eventually twigged that this is a function of the number of teeth per revolution of the hob. Essentially the hob cuts the tooth form as a series of flats. For the proper worm wheels I improved this faceting by moving the hob axially after full depth was achieved. The hob was moved one pitch of the worm, 0.5", in steps of 1/16" and at each step the worm wheel was allowed to make a complete revolution, driven by the hob. Although slight there was a definite change in the sound of the cut as the worm wheel completed a revolution.

Finally here are the worm and worm wheel installed on the engine:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Steering_worm_MEM_6.JPG)


Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on October 07, 2016, 09:37:30 PM
Terry: So if I understand it the split pins are a later addition rather than original fit?

Andrew                 Made that way from day one as far as I know.



                            Steering bits look good............                  Terry
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Kim on October 08, 2016, 06:58:26 AM
Those are some mighty fine looking gears you cut there Andrew!  And I KNOW it isn't as easy as you made it look!
Kim
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on October 08, 2016, 11:40:19 AM
Terry: That's interesting, I'll have to look more carefully at some full size engines when I get the chance. However, it's probably a step too far to add them to my engines. I have enough diversions as it is.

Kim: You obviously speak from experience! In retrospect the worm wheel was reasonably straightforward. For the worm the biggest issue was faffing about with feedrates in Mach3. The outline given is the sanitised version. :o After my CNC controller had a wobbly last year (turned out to be an iffy HDD connector) I took the opportunity to buy a new controller and upgrade to Tormach PathPilot. I haven't played with the 4th axis yet, but I live in hope that the feedrates will be interpreted correctly.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on January 24, 2017, 08:55:42 PM
The governor on my traction engines uses two 1:1 bevel gears to transfer motion from the horizontal to the vertical. They are specified on the drawing as 18 teeth and 18DP, so a PCD of 1". I designed these in 3D CAD some while ago, while looking at the overall design of the governor. Having recently fitted a high speed milling spindle to the CNC mill I thought I'd try it out by machining the governor bevel gears. When looking at cutter sizes it became clear that I needed a 0.8mm diameter cutter to get into the tooth root at the inner end of the bevels. A 0.8mm cutter came out at 32 - I don't think so! Of course I could have used a (cheaper) 1/32" cutter. But I'd already gone ahead and bought some 1mm diameter carbide ballnose cutters. So I did a quick redesign on the gears to be 16 teeth and 16DP; still a PCD of 1" and I could use the 1mm diameter cutter. I used a pressure angle of 20 degrees. Here are the two gears in a 3D assembly:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Governor_Bevel_Gears_1.jpg)

Deriving the CAM program for the gears proved rather problematic. I spent ages adding circles on the gear to act as limits for the machining. The toolpath drawn by the CAM program looked good. But plotting out the G-code generated revealed some odd arcs that seemed to run the cutter through solid metal. After a lot of faffing about I simply added some radial and axial limits, by typing into boxes in the setup pages and was rewarded with a sensible looking toolpath and G-code.  :ThumbsUp: Here are the combined toolpaths:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Governor_Bevel_Gears_2.JPG)

There are three steps. A roughing step with a coarse stepover, and stepdown, to remove most of the metal. This was followed by a prefinish profiling cut, leaving 0.2mm of stock, to clean up any nasties left from roughing. I've been bitten in the past where odd areas were not machined away as expected and consequently the cutter broke while profiling. The final operation was a profile cut with a fine stepover. Here's the high speed spindle in action on the CNC mill:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Governor_Bevel_Gears_3.JPG)

The spindle was running at 24000rpm with a feedrate of 350mm/min. For roughing stepover and stepdown was 0.3mm. For the prefinish profiling stepover was 0.1mm and for the final profiling stepover was 0.04mm. This is finer than needed for the tops of the teeth, but is dictated by the relatively steep flanks of the teeth. Too large a stepover leaves a 'steppy' finish on the tooth flanks. I also had to tweak the G-code to remove tool length setting via the tool table, as the spindle doesn't have a quick change collet. So the Z axis has to be referenced every time a tool is changed. That was one factor in deciding to do everything with a 1mm cutter, rather than be a smartypants and rough out with a bigger cutter before profiling. Total machining time was around 3-3/4 hours. But of course one doesn't have to baby sit the mill. For the first time ever I actually left the house with the CNC mill running to walk up the road to the local garage for emergency chocolate rations.

Here are the four gears (two engines) and the aluminium test gear; aluminium being somewhat cheaper than bronze:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Governor_Bevel_Gears_4.JPG)

Not that it really matters, but these are true bevel gears. I was very pleased with the way the Tormach behaved, these are pretty small gears and all the movements were only a few millimetres, but everything worked fine. Well almost everything. PathPilot had a wobbly after I'd left the mill on overnight so as to not lose work references. It ran the G-code fine, but I noticed that the axis displays were not being updated, although the DTG numbers were changing. I resisted the temptation to fiddle with it while the program was running. After it finished none of the screen buttons or the jog controller worked. I had to reboot the controller. I probably ought to upgrade PathPilot to a newer version.

These are the last gears on the traction engine to make. :'( So now I'm going to have to knuckle down and get on with assembling the wheels.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Admiral_dk on January 24, 2017, 09:22:35 PM
I was going to point out that you can get some nice Chinese carbide mills down to 0.8mm at a very good price when you search for those to do PCB work on AliExpress ...!... and then I realized that you needed ball nose mills ...  :slap:

I still like the gears - they look good  :ThumbsUp:
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on July 22, 2017, 09:59:05 AM
Obviously I've been caught up in the Photobucket farrago. I only use them for hosting pictures on this site, so they can go to hell on a hand cart before I pay. I have exact copies of the hosted pictures on my computer, so it's no concern if my account gets closed.

In due course I'll decide whether to edit this thread and reinstate the pictures by other means, or just leave it and move on. It'll probably come down to the time involved.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 11, 2017, 09:52:56 PM
Decision made! I have transferred all my pictures to a new host, and will slowly update the pictures in this thread. In some fantasy world where I have unlimited time  :ROFL:  I might try and do the same to some of my other posts.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Kim on August 12, 2017, 05:11:24 AM
Where are you hosting, Anderw?  I'm using Ade's coppermine site he setup and that's working well. And the price is right!
I'll be glad to have your pictures back!
Kim
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 12, 2017, 09:24:05 AM
I'm using Ade's coppermine site he setup and that's working well. And the price is right!

Me too.  :ThumbsUp:

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 17, 2017, 10:57:19 PM
I think that is all the pictures in this thread updated. All I've got to do now is go through my other posts.  :???:

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Kim on August 17, 2017, 11:59:46 PM
Wonderful!  Thanks for taking the time and effort to update your pictures Andrew!  :ThumbsUp: :)

I was looking back through your build here and noticed one of the pictures still showed the PhotoBucket Ransom notification.  I was going to tell you that yo missed one, but then realized that it was actually Jo's picture that was missing!  Not yours!

I'll bet we end u with a bunch like that, where someone else has posted on a thread and doesn't remember exactly what or where so it doesn't get updated.   Ah well, such is life.

Your thread looks great!  Thanks for taking the time to update Andrew,
Kim
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 18, 2017, 10:51:16 AM

I was looking back through your build here and noticed one of the pictures still showed the PhotoBucket Ransom notification.  I was going to tell you that yo missed one, but then realized that it was actually Jo's picture that was missing!  Not yours!


I noticed that too; don't suppose it'll get fixed, but there are worse things in life to worry about.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jo on August 18, 2017, 10:57:51 AM
I am slowly going through and updating my own threads with Copper mine pics but it is difficult to know where I might have linked photos from Ransomsuckit  on others threads  :-\

Jo
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 18, 2017, 11:06:56 AM
I recently fitted the drive to the water pump. I've been putting it off for months, as it would involve dismantling half the engine. And I knew I'd be disappointed if the tight clearance between the connecting rod and ram turned out to be wrong.

In the event just removing the flywheel side crankshaft bearing and housing, and loosening the other side, was enough to get the eccentric onto the crankshaft. There is a small U shaped bracket that sits into the ram and holds the gudgeon pin for the connecting rod. I made the pin and fitted the bracket. In passing I thought it was odd I couldn't find the bracket for the second engine; must have put it in a special place. Everything was fitted - and disaster. Something hard was stopping the ram being fully inserted into the pump as the crankshaft rotated.  :-[

After a sulk I fired up the 3D CAD model to track down the error. All seemed fine in the model. The first thing to check was the position of the ram when fully home. I took off the water pump and ram to investigate the internals. And out fell the second U shaped bracket, some special place!

With everything re-assembled I'm pleased to say that the water pump drive works fine. The eccentric drives the water pump quite happily when the flywheel is turned, despite there being no grub screws holding it to the crankshaft at the moment. So there can't be much friction in the system. Here's the complete assembly:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Water_Pump_MEM_8.JPG)

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on August 18, 2017, 07:41:20 PM
Glad to see you are back at it Andrew              Best Wishes    Terry
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 27, 2017, 09:25:10 PM
That should be all my pictures updated across all my posts. Let me know if I've missed any. I can now give Photobucket a Harvey Smith.

After that back to governors. Like a lot of other things on my engines these have turned into a significant piece of theory and design. It's interesting to note that the governor can be described by a second order differential equation, the solution of which results in two complex conjugate poles on the s-plane, which determine the response of the governor. I'm familiar with the s-splane as it is fundamental to understanding filter design and characterisation. But it's going to take a bit of work to understand the application to mechanical governors. Of course that may be a load of old balls, but balls are important. Scaling works against one when it comes to the mass of the balls. So as well as increasing size a bit over scale I'm looking at high density materials. Gold, platinium and indium are out due to cost, and depleted uranium might bring a glow to the cheeks. Instead I am experimenting with tungsten and its alloys.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on October 09, 2017, 05:26:59 PM
Machining tungsten has proved to be something of a saga.

First I tried pure tungsten. It turned ok with inserts, but didn't leave a particularly good finish. However, drilling and tapping proved to be very difficult. If the tool didn't break the material cracked, as it is brittle, just like the datasheets say! Here's what can happen when hand tapping:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Governor_Tungsten_1.JPG)

Next I tried a tungsten alloy, 87% tungsten, plus nickel and a bit of iron and cobalt. This turned beautifully with insert tooling, leaving a nice finish on the order of 2m Ra. Drilling and tapping again proved difficult. The material is sintered rather than being truly homogenous and is quite abrasive. I found that HSS drills worked, but the tips were blunt after one hole. After some experimentation I tried slow helix carbide drills - they worked very well with the swarf coming out as fine particles, like brass. Tapping still proved difficult. The material suppliers advice is that since tungsten has a high Young's modulus it tends to grip the tap, so one should use spiral point, or spiral flute, taps intended for such materials. I bought some posh (and spendy) taps for same, and they didn't work. They'd do a turn or two and then the material gripped them so tight it would put a boa constrictor to shame. It's amazing how far a HSS tap will twist before it breaks.  :o  I dropped from a thread depth of 50% to 10% and still no success. I managed to make one trial ball, but it wasn't really satisfactory for production.

After a sulk, and to let the bank balance recover, just out of curiosity I tried a fairly worn set of M4 Dormer hand taps. To my surprise the taper and second tap cut a 50% depth thread very nicely. The bottom tap still had a tendency to get involved in a death grip if you turned it too far. Armed with this information I made a second test ball. Here are the parts before assembly:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Governor_Tungsten_2.JPG)

The small holes are 1.2mm diameter and drilled 8mm deep before forming the hemisphere, which was done using a hydraulic copying unit. The small screw that holds the two hemispheres together is made from a tungsten/copper alloy. It machined well, and took a good thread with a die. I haven't tried threading it with a Coventry diehead yet. This is the complete assembled test ball:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Governor_Tungsten_3.JPG)

All the tungsten and alloys were bought via Ebay. A local metal stockist wanted 689 for a 300mm length of 25mm diameter tungsten/nickel alloy. Told 'em that was more than the project could stand. Now that I've sorted machining the tungsten I can start designing the governor. This starts with the balanced valve, which will give me the movement needed for fully open to fully closed, from which simple geometry will give me the distance the balls need to move and hence the centrifugal forces involved. That will then allow me to calculate the controlling force needed from the leaf springs, and hence determine the size and material needed for the springs. Here is the basic balanced valve and body:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Governor_Balanced_Valve.jpg)

It'll need some fine tuning, and I also need to check the space available in the cylinder block.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on November 06, 2017, 11:07:24 PM
The front wheels for my traction engines have been a bit of a saga. In order to roll the rims I designed and made a set of bending rolls, specifically to fit on the milling machine table:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Front_Wheels_1.JPG)

Once rolled the rims were arc welded together. I had planned to cut a groove in the rolls to form the T-rings, but instead chose to get them laser cut. To save material I had them cut as quadrants which I then welded together. Care was taken with the measurements so that I ended up with rings rather than ovals. In retrospect it would have been quicker, and probably cheaper, to roll the T-rings. It was satisfying that the T-rings slipped into the rims with the aid of a few taps from a hammer. After fitting the T-rings were welded both sides. It may not look pretty but the wheels are not going to come apart.  :)

All the spokes were CNC milled from annealed cold drawn steel. I am building two engines, one of which will have steel tyres and strakes and the other will have rubber tyres fitted. The quadrants for the front wheel tyres were rolled as per the rims and riveted to the wheel rims with 3/16" steel rivets. Despite concerns that I had over done the countersinking on the tyres the rivets just filled said countersinks. Here are the spokes being fitted, using the same plate I use for welding the T-rings into the rims, so all the holes for clamps are already there:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Front_Wheels_2.JPG)

The spokes are bent using a box 'n' pan folder, albeit some what over it's specified material thickness. :o  Here are two completely spoked wheels, one with steel tyres and one not:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Front_Wheels_3.JPG)

Note that the three rivet holes on the spoke palms are on an arc not a straight line. That should keep the rivet counters quiet.  One last thing to try was checking the wheel runout. A crude check by spinning the wheel on its axle and watching a rule close to the rim suggests that maxiumum runout on the rim and side to side wobble on the side of the rim is about 1mm worst case:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Front_Wheels_4.JPG)

Of course there's still a lot to do; all the spokes need riveting and then on to the rear wheels. Most of the parts for the rear wheels are done, but there is still some welding and machining on the hubs to do.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Kim on November 07, 2017, 01:45:24 AM
Nice to see more progress on your traction engines.  The wheels look great!  And, of course, I can't go too long with out mentioning how HUGE they are!

Nice set of rollers you made there too.  The seemed to do the trick.
Kim
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jasonb on November 07, 2017, 07:19:01 AM
Andrew, will you rivit the ones to be vulcanized before having that done? I have seen some sent with just bolts in the holes so that the wheel can be taken apart and cleaned up afterwards then rivited with the rubber on.

Looking good, you will soon be pushing them around the house making chuff, chuff noises!
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: kvom on November 07, 2017, 10:55:38 AM
Just caught up with this thread.  Superb work.

WRT to tapping tungsten, I suspect thread milling would have worked well.
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on November 07, 2017, 12:01:04 PM
And, of course, I can't go too long with out mentioning how HUGE they are!

Yep, the OD of the front wheels is 15", the rears will be 24". The bending rolls are initial pinch, so if you swap the work end for end at each pass you don't get flats on the ends. The process can be modelled as simple beam bending, fixed at one end and a point load at the other end. The stresses need to be high enough to exceed the yield point of the material. If I recall it was something 1000lbs force?

The company I spoke to regarding the rubbering (Reliant Rubber in Batley) wanted the wheels assembled beforehand. At least I think that's what they said; I had some difficulty with the accent.  :embarassed: They also shot blast and prime after vulcanisation. So I think I will rivet the wheels aforehand, but leave the hub covers off. Ideally I would collect the wheels without priming so I can add neat fillets to the wheels. I will be consulting a mate who has already used the company.

Thread milling was suggested on another forum for the tungsten alloys. I'd like to try thread milling, but I could see me breaking a lot of expensive cutters learning about thread milling with M4 in tungsten. That would have deeply upset my wallet.  :'(

Here are the front spokes:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Front_Spokes.JPG)

And the rear spokes, which need a bit of a clean up:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Rear_Spokes.JPG)

All the spokes were cut with a 6mm cutter, three roughing passes full width and 2.2mm deep, and a finish pass at full depth, taking off about 0.4mm. The rear spoke design has been changed to incorporate four rivet holes as per full size. The palms are slightly narrower than originally drawn. The specified width is 2-5/8" which is not a standard size. Buying 3" wide stock would have been a lot more expensive than 2-1/2", so I went with the latter. The rear hubs are ovoid, so the rear spokes are of different lengths. However, having drawn everything in 3D CAD it was clear that I could get away with only two lengths, trimming on assembly, which I will be doing anyway. I also had some machining problems. After an initial issue with over-ambitious feedrates all was going well until I heard a 'orrid noise coming from the workshop.  :o The milling cutter had lost it's teeth and to give the Tormach mill it's due it was still pushing a by now rather crude ballnose mill through the work. I changed the cutter, and the blank and continued without a problem. At the end I tried the blank which had broken the cutter previously. The cutter went a bit further, but then broke in the same way. All I can think of is that something was wrong with the material, possibly something in the mix that shouldn't have been there.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jasonb on November 07, 2017, 01:13:06 PM
I had similar with a bit of 2"x1" black bar recently, found a hard spot in it that killed 3 carbide cutters not to mention the HSS ones that found the hard spot first. It wa smentioned that the very end of a bar from the mill can have hard spots, I assume when being rolled the end cools quickest or gets chilled
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on November 18, 2017, 08:19:53 PM
Andrew,       Reliant did my tyres. I chose them on a balance of price and reccomendation . Their service and their product is excellent.
                    I would only have your wheels left unpainted if you intend to collect them as soon as they are ready. They will be blasted and start to oxidise immediately. Reliant's primer on my wheels was a fine, even coating that needed minimum flatting.

Best Wishes          Terry
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on November 18, 2017, 10:27:10 PM
Thanks Terry, another thumbs up for Reliant. They're also relatively convenient to visit on my trips up north. I've been dithering about getting the wheels painted after shot blasting as I want to tidy up the welded fillets. But it sounds like I should get them primed and sort out the fillets as best I can. I certainly don't want to be cleaning assembled, but rusty, wheels.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on January 15, 2018, 11:42:26 AM
This is an interim progress report on my traction engine rear wheels. The rationale for working on the wheels is as follows:


The rims and T-rings have been machined, rolled, welded and fettled over some considerable period. Likewise the hubs, except for some odd reason I failed to drill and tap the holes for the spokes when machining the hubs. So I had to set up again and get them done. At least with a reversing tapping head running at 500rpm threading was way quicker than by hand. Here is a rim and hub on my build jig, the rim is propped up by " as on the left hand wheel the hub is offset so the wheel clears the flywheel. The build plate is scrap aluminium. When buying aluminium for work from my stockholder I also asked them to dig out a piece at least 650mm square and around 10mm thick. I didn't care about dings or nicks so I got the plate at a greatly reduced price, and the stockholder got more than scrap value.  :ThumbsUp:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Rear_Wheel_1.JPG)

The spokes were bent to the appropriate angle in my box 'n' pan folder, operating somewhat over it's design limit.  :embarassed:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Rear_Wheel_2.JPG)

It takes me about 20 minutes to fit each spoke. Here is the build well under way, one side done and the other side started:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Rear_Wheel_3.JPG)

And finally two wheels done, one left hand and one right hand. There are no strakes, as these wheels will be going to have rubber tyres fitted:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Rear_Wheel_4.JPG)

Next job is to make a jig to drill the remaining three rivet holes in each spoke, and then get them riveted.

I wouldn't want to pre-empt Kim from commenting on size, but the rule shown is 24".  ;D

Andrew

Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Perry on January 15, 2018, 12:51:45 PM
Really impressive!
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jasonb on January 15, 2018, 01:22:03 PM
Good to see you got some more of the engine done over the Xmas Andrew, the remaining six should be plain sailing.  :)

J
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Kim on January 15, 2018, 05:24:29 PM
Well, Andrew, I don't feel preempted, I just feel validated!
And I'm glad you mentioned that it was a 24" rule there, otherwise I might have assumed it was a 6" rule and thought it was a normal sized model!

Boy, those wheels are BIG!   :o

Kim

Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on January 15, 2018, 08:00:50 PM
Hi Andrew,   Just been catching up on your build via TT. I'm glad your work "issues" seem sorted.. I can certainly recommend the 3day week-4day weekend routine. Engine bits all looking good :ThumbsUp:
Regards        Terry
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on January 17, 2018, 10:44:12 AM
Boy, those wheels are BIG!   :o

Not only are they big they're darn heavy. It was quite a strain lifting them on and off the build jig.  :o
I've been told that once rubber tyres are fitted it about doubles the weight. If I want to move them afterwards I'll have to roll them; good job they're more or less round.  :ThumbsUp:

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on January 17, 2018, 11:44:10 AM
Yes,  Extremely heavy with the rubber on :help:   Terry
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on January 18, 2018, 10:21:02 AM
Terry: thanks for the confirmation. Better get an engine crane on order.  :)

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on April 08, 2018, 09:34:22 PM
All the spokes on my traction engine wheels are fixed using 3/16" steel rivets. I've been experimenting with closing said rivets, before working on the wheels. I made some rivet snaps, and a jig for the front wheels. The snaps are made from silver steel and are hardened and tempered. The jig is hogged out of a lump of hot rolled steel:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Riveting_1.JPG)

During the experiments I closed a lot of rivets:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Riveting_2.JPG)

Initially the rivets were closed by hand. But I just didn't seem to be able to apply enough force to properly form the domed head, even with a lump hammer. I have been considering the use of a hydraulic press to close the rivets, partly from noise considerations. The problem with a hydraulic press is that the cheap ones are not wide enough for the rear wheels. I found a press online that would be wide enough for both front and rear wheels, but it was 700.  :o So as an interim measure I decided to try my #3 flypress. This was bought years ago on Ebay and has been used to stamp out sheet metal parts using home made press tooling. Experiments showed that it was perfectly capable of closing a rivet. However the bench was less capable! It needs strengthing with a length of steel angle before I go too much further. The experiments also gave me a figure for the length of rivet that I needed before closing to form a proper domed head.

Here is the flypress setup for riveting the wheels, fudge it and bodge it are in charge of the wheel holding:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Riveting_3.JPG)

And a close up of the riveting jig arrangement:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Riveting_4.JPG)

I started by filing each rivet to the required length, but that got tedious rather quickly. So I've now made a small split collet holder that I can use in the Britan repetition lathe, along with a sprung loaded backstop, to machine the rivets to length. It only takes a few seconds each. The home formed heads seem pretty fair to me, especially when they are closed against the T-ring rather than the spoke, dunno why that should be:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Riveting_5.JPG)

For the front wheels the home formed heads are on the inside, but this is good news for the rear wheels where the home formed heads have to be on the outside, in full view of the rivet counters. So far two front wheels have been riveted:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Riveting_6.JPG)

Two more front wheels to go, and then on to the rear wheels.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Kim on April 09, 2018, 05:35:00 AM
Nice looking rivets there, Andrew! Looks like you've got that figured.

You are getting very consistent looking round heads on your rivets too.  You should feel quite proud of that!

Kim
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on April 24, 2018, 09:33:58 PM
You are getting very consistent looking round heads on your rivets too.  You should feel quite proud of that!

I am quite pleased with the rivet heads. The riveting isn't perfect, but then again neither is full size.

I've recently had a "good grief I actually finished something" moment; vis the front wheels.  :o Before fitting the hub covers I went a bit over the top and pinned each spoke with a 6mm dowel pin. All done freehand, hence the somewhat cavalier placements:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Front_Wheels_5.JPG)

I didn't add a layer of glue between the hubs and the covers, as sometimes mentioned, as I didn't think it would add to the fit. However I did spread a thin layer of Araldite across each spoke, where it leaves the hub, to fill a slight gap. On the wheels with steel tyres I also fitted the bronze bushes with bearing retainer, and the oiler pipes. These were left off the two wheels that will be going to have rubber tyres fitted as I think the vulcanisation process will be too hot for the retainer. Here are the four wheels, artfully arranged on the sitting room carpet:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Front_Wheels_6.JPG)

For scale the wheels with steel tyres are 15" OD, just in case anyone was wondering.  :)

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: zeeprogrammer on April 24, 2018, 11:34:10 PM
They look fantastic.  :ThumbsUp:

15"! Wow.
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Dave Otto on April 25, 2018, 01:12:59 AM
Beautiful job on the wheels Andrew!
I really enjoyed seeing how you approached the riveting.


Dave
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: yogi on April 27, 2018, 05:03:24 AM
Always good to see your techniques Andrew!
Thanks for sharing.  :ThumbsUp: :ThumbsUp: :ThumbsUp:
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on April 28, 2018, 07:52:58 PM
Thanks for the kind words; I really appreciate them.  :ThumbsUp:

As an antidote to riveting I've been machining the chimney base and perch bracket castings, details to follow soon.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Steamer5 on April 28, 2018, 11:13:42 PM
Hi Andrew,
 The wheels came out very nice indeed!
The rivets look the business to. How did you form the hollow in the snaps please? Ive had a play using ball end mills which do a nice job, take the hole to a little deeper than required then turn back so the rivet is flush to just proud, seems to work ok, but your rivets look way better.

Cheers Kerrin
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on April 29, 2018, 09:45:39 PM
The rivets look the business to. How did you form the hollow in the snaps please? Ive had a play using ball end mills which do a nice job, take the hole to a little deeper than required then turn back so the rivet is flush to just proud, seems to work ok, but your rivets look way better.

Same way, with a ballnose endmill. For the preformed head I set the depth so the rivet head was slightly proud, about 5 thou give or take. For the snap that forms the head I ended up grinding a few thou off the depth, and also tapered the bottom edge away from the rivet. That is so that even if the snap for the formed head hits the spoke it doesn't leave an annular mark, just a slight rim around the rivet. I found that rivet length was pretty important to within a few thou. Too short and you end up with a dome on a cylinder as there isn't enough metal to fully form the head before the snap contacts the spoke. Too long and you end up the with the same as although the metal fills the snap the snap is still proud of the spoke. It takes a lot more force to extrude the metal sideways and outwards from the snap through the gap between spoke and rivet. If that doesn't make sense I'm happy to take some pictures of my rivet experiments to try and clarify what I mean.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Steamer5 on April 30, 2018, 05:36:52 AM
Hi Andrew,
 Many thanks for the explanation. Think I follow what you did.....a couple more coffees will help the thought process. And yes please more photos will definantly help!
I have a bunch of 3/16 rivets for the main frames of the loco build to put in, so any helpful hints & tips will be most welcome.

Cheers Kerrin
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on April 30, 2018, 10:56:52 AM
Looking good Andrew.............Terry
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on May 01, 2018, 08:50:55 PM
Thanks Terry, I've got quite a way to go to catch up with you!

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on May 01, 2018, 09:08:53 PM
And yes please more photos will definantly help!

Here's a picture of the last set of riveting (in one sense) experiments I did:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Rivet_Trial.JPG)

Starting at the front from the right:

The first rivet is the wrong way round, commercial head at the top  :embarassed:

Next left is a full length rivet, it's not too clear but the formed head is a dome on a cylinder, the cylinder being about 20 thou high. The rivets are nominally " but measure 0.885" overall

Left again is a rivet filed to be 0.875" long, again a dome on a cylinder, but the cylinder is slightly lower

Left again is a rivet filed to be 0.860" long, but it's the wrong way round too  :embarassed:

Front row on the left is a rivet filed to be 0.855" long, the head is a dome on a cylinder with the cylinder about 12 thou high

Rear row on the left  is a rivet filed to be 0.850" long, the head is a dome on a cylinder with the cylinder about 8 thou high

Rear next right is a rivet filed to be 0.840" long, the head is still a dome on a cylinder but the cylinder is almost imperceptable, less than a few thou

Next right is a rivet filed to be 0.830" long, the head is a dome on a cylinder but the cylinder about 8 thou high, so is getting higher

This gave me good indication of what length to make the rivets. After fine tuning on the wheels proper I settled for 0.845" (possibly slightly long) and a few good final swings of the flypress to ensure proper closure. It's probably better to be slightly too long than too short.

BF & BI wins out every time.  :)

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Steamer5 on May 02, 2018, 05:03:30 AM
Hi Andrew,
 Many thanks for the picture & explanation, just goes to show how very small differences make a reasonable difference to the shape / height of the shop formed head.

Cheers Kerrin
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on May 13, 2018, 09:29:43 PM
As well as the front wheels I've also been working on other parts for the front end of the traction engines. One of these is the perch bracket which is bolted to the smokebox and holds the pivoting bracket on the front axle. The perch bracket is a casting, which is fairly simple to machine. The first operation is to drill and bore the hole in which the pivoting bracket will sit. The boss on the casting is set "true" by eye ready for drilling, the drill shown is 15/16":

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Perch_Bracket_1.JPG)

Once drilled, bored and faced, the boss and bottom of the bracket can be machined. The drawings are wrong in respect of the length of the boss. Generally traction engines sit slightly nose up in an attempt to keep the top of the firebox covered with water as the road undulates. Although unspecified on the drawing the length of the boss is shown as about 3/16". I made mine a bit over 7/8", which is nearer what it should be for the front axle being " higher than the rear. In fact it's about 11 thou out, but I'm not going to worry about that:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Perch_Bracket_2.JPG)

At the same time as the inner face of the boss was machined the rear face of the casting was also skimmed flat to act as a reference face for subsequent machining operations. I also drilled a small hole in the rear face so I can access the grub screws in the collar that holds the pivoting bracket in place. On the front of the perch bracket is a towing eye. Having drilled the hole for the towing pin the bottom of the slot is formed by drilling:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Perch_Bracket_3.JPG)

Turning the casting through right angles the slot can then be machined with a 12mm slot drill. The 0.5" gauge block is used for sizing the slot; not really necessary but I like things just so:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Perch_Bracket_4.JPG)

To machine the curved surface on the perch bracket that mates with the smokebox I needed to make a flycutter, which is hogged out of a lump of hot rolled steel:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Flycutter.JPG)

The diameter across the flycutter is precisely 8" and was turned at the same setting as the arbor hole was drilled and bored so concentric is assured. Since the picture was taken I've added a keyway slot in the bore and a plate to help locate and clamp the tool. Since I know the diameter of the flycutter body gauge blocks can be used to set an angle plate at the correct distance for tool setting, so the correct radius is generated. In this case I need a radius of 4", so the gauge block is 0.75":

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Perch_Bracket_5.JPG)

After some tentative cuts I ended up using a depth of cut of 80 thou and 8 thou feed per rev, easy to hand feed on my metric mill as it is about 0.2mm; the flycutter was rotating at 41rpm. The flycutter didn't even cough and left a really nice smooth finish with no tool marks:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Perch_Bracket_6.JPG)

That's one of the plusses of a horizontal mill, they make a brick built s**t house look flimsy!

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on June 03, 2018, 10:22:37 PM
Slow progress on the engines at the moment. Now the nice weather, relatively speaking, after all this is England, is here every man and his dog wants his glider signed off so it's legal to fly. Thus I've been bogged down in surveying gliders and checking paperwork over the past few weeks.

On the theory side of the engine I've been reading the original Pickering governor patents. I now have a clearer idea of the proper operation of the Pickering governor, and it's also clear that there are some major boo-boos in the design as drawn, over and above the use of a non-balanced valve. So I'll need to re-design the valve spindle drive in due course.

On a practical note I've been preparing for riveting the spokes on the rear wheels. The formed rivet heads on the rear wheels are on the outside, and therefore in full view. They need to be right! A new fixture has been designed, and checked that it fits all four rivet positions per spoke in CAD:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Rear_Wheel_Riveting_1.jpg)

Annoyingly one thing that came out of the CAD model was that I couldn't use the 20mm diameter rivet snaps I used for the front wheels. Due to some idiot  :embarassed: choosing to use a zig-zag rivet pattern as per full size rather than on a circle as drawn no way no how would the 20mm snaps fit. So I had to make a new set that are 16mm diameter. Here is the new riveting fixture and snaps ready for action on the flypress:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Rear_Wheel_Riveting_2.JPG)

The "rust" is a trick of the camera; that's my excuse and I'm sticking to it. When I riveted the front wheels I used a lump of " thick steel plate to cover the hole in the flypress base. For the rear wheels this raised the riveting fixture too high to fit under the press. I tried a " plate but it just folded. A piece of " plate was passable but I think the fixture was flexing slightly, and the handle was in an awkward place to get a good swing on it. So I reverted to plan A which was to fill the hole with a " thick slug of steel, as seen in the picture. The slug was hogged out of some 25mm thick hot rolled steel, as I have a lot of it in stock. Knocking the corners off the as cut square in the lathe at 540rpm and 4 thou per rev feed made the floor vibrate.  :o  But the carbide insert seemed to survive.

Having made new snaps I had to revisit my riveting trials. After a few tweaks to the rivet length, and the snaps, I've closed a number of test rivets that look acceptable:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Rear_Wheel_Riveting_3.JPG)

Next job is to weld up some 50mm square steel tube to make a T-piece the same height as the flypress base to support the outer edge of the rear wheel. Then let riveting commence!

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: zeeprogrammer on June 03, 2018, 10:59:09 PM
What are those 4 objects within the spokes?

I have to admit, at first I thought I was looking at a paddle wheel.  ;D
But that's me.
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: crueby on June 03, 2018, 11:36:54 PM
What are those 4 objects within the spokes?

I have to admit, at first I thought I was looking at a paddle wheel.  ;D
But that's me.
Thats the rivet fixture he was describing, checking clearance at the four rivet locations.
Gotta stop just reading the pictures Zee!   :ROFL:
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on June 03, 2018, 11:38:42 PM
What are those 4 objects within the spokes?

Sorry, I didn't explain it very well. The four objects are copies of the riveting jig to check that I could reach all four rivet positions while clearing the spoke, having clearance for the lower T-ring and enough vertical movement to slip the preformed rivet head into the lower snap.

Andrew

PS: I see I've been beaten to the explanation! Too slow on the typing; I blame the third glass of wine.
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: zeeprogrammer on June 04, 2018, 12:51:03 AM
Too slow on the typing; I blame the third glass of wine.

When you get to the fourth...you don't care.  ;D
With my stinking hoppies...I don't have to work to the fourth. The second one is sufficient.  :Lol:

Thanks for the explanation Chris and Andrew.
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on June 19, 2018, 09:10:08 PM
Riveting the rear wheels has been ruddy hard work. And there are a lot of rivets, 64 per wheel. Everything is heavy and nowt is square with anything else. So it's been two steps forward and one back a lot of the time. Due to boo-boos, or I wasn't satisfied with the result, I've had to drill out and replace a few rivets. It's taken quite a while to get a working system. I've even dropped the wheel a couple of times. Darn glad I recently bought some steel toecap slip on shoes for use in the workshop. Saved a potential trip to A&E. Here's the general setup:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Rear_Wheel_Riveting_4.JPG)

The height of the rim is on the limit of my #3 flypress, so I can't use the bar support as per the front wheels. I thought of using a transmission style jack, but they're quite expensive for something that will only be used once. So I welded up the stand to the left from 50mm square ERW tube. It was intended to use the stand at right-angles to the position shown, but that didn't work as nothing was square and it meant I couldn't easily tilt the wheel slightly. Here's the riveting fixture in close up:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Rear_Wheel_Riveting_5.JPG)

I had to make a few adjustments to the rivet snap heights. I made the snaps in a bit of a rush and rather over tempered them during heat treatment, somewhat over 300C rather than the intended 270C. They worked, but the top snap got a bit expanded at the top. Here are some of the closed rivet heads, acceptable and I plan on using thick paint when the times comes:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Rear_Wheel_Riveting_6.JPG)

As before I pinned the spokes into the hubs with dowels and put a smear of araldite on each spoke before finally screwing the hub covers down. Shown here are the two finished wheels. Note the zig-zag rivet pattern, as per full size, rather than in a line as shown on the drawings:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Rear_Wheel_Riveting_7.JPG)

One of the problems I had was the riveting jig bending at the bottom toe:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Rear_Wheel_Riveting_8.JPG)

First time I noticed this I machined the base flat and then machined a 1 taper so the jig leant slightly back to account for the T-rings not being exactly square with the rims. It didn't make any difference. So before I rivet the next two rear wheels I'll strengthen the base so it doesn't bend so easily.

I've now got a complete set of wheels that I can send away to have proper rubber tyres fitted. But I've still got two more wheels to build. It's mostly going to be tedious. The only problem to solve is how to form the strakes so that they are a nice fit on the anything but straight rim. I've tried the usual methods of twisting them in a vice and putting them through rolls. Neither worked to my satisfaction. The current plan is to make some curved press tooling that replicates the shape of the rim and press the strakes red hot before fitting.

Andrew

Edit: Dunno why almost everything was doubled up? I blame cut 'n' paste finger trouble and red wine.
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: deltatango on June 20, 2018, 12:09:36 AM
Andrew,
It's good to see progress on the two engines. Not having much room to spare in the workshop must also be a problem for moving heavy objects around. I've learnt a lot about riveting for your posts - thanks!
Regards, David
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Kim on June 20, 2018, 06:34:18 AM
Nice rivet work on your wheels, Andrew!  Looks like your rivet jig worked quite well!
Kim
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on June 26, 2018, 03:37:27 PM
It's good to see progress on the two engines. Not having much room to spare in the workshop must also be a problem for moving heavy objects around. I've learnt a lot about riveting for your posts - thanks!
At least one can roll the wheels for most of the distances needed. Lifting them onto the mill/flypress is more of an effort though. I'm glad you've gained something from my trials and tribulations.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 11, 2018, 10:01:44 PM
While working on the front end of the traction engines I thought I'd have a go at the smokebox door and nameplates. These are supplied as castings:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Smokebox_Door_1.JPG)

Turning the back of the smokebox door, and creating a register to allow the door to be held front face out, is simple:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Smokebox_Door_2.JPG)

When turned round the OD can be brought to size. To machine the front face requires a large radius to be turned, 18" in this case. Normally I'd fudge it with some angled cuts, files and emery. But the nameplates need to fit neatly on the front face so I need a means of creating an accurate radius, and a matching radius on the underside of the larger nameplate. I have a hydraulic copying unit and while these are nornally used for profiling parts parallel to the lathe axis there is no reason why they cannot be used for facing. Accessories were available for this, but it seems to have been quite a rare operation, and there is very little information on the internet. Generally my lathe already has mounting holes and brackets for 3rd party accessories, like the copying unit. But there is nothing on the saddle to hold a bar that then holds the template for facing. So I came up with a simple clamp arrangement, and hogged a profiling bar out of a lump of hot rolled steel:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Smokebox_Door_3.JPG)

For those interested in scale the bar is 20" long. I was keen to get the bar made so I ran the Bridgeport hard, in a subdued light the swarf was coming off red hot and didn't half hurt if you got hit by it. When roughing out the rebates with a 10mm endmill I used a DOC of 5mm, WOC of 7.5mm and a feedrate of 300mm/minute at 2000rpm. The force needed to turn the table handle in the climb milling direction was significantly lower that for conventional milling. So that's what I did, climb milled.

A simple sheet metal template was hand cut from sheet, and the curve machined on the CNC mill, less than 3 minutes machining time! Here's the setup in action machining the front of the smokebox door. I had some issues with surface finish and found that feeding from the outside to the centre worked best. Which, if I'd thought about it, gives a better cutting geometry for the profiling insert:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Smokebox_Door_4.JPG)

Profiling the back of the outer nameplate is similar, using a second template. The door and nameplates fit together snuggly with no rocking:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Smokebox_Door_5.JPG)

I'm not overly happy with the lettering on the nameplates. The outer nameplate can be tidied up with a small chisel and files. But the inner nameplate has lost significant resolution as there is a large draft on the letters and the depth of the recess is not constant. So when the front is skimmed the letters come out different widths. Of course I could ignore it and just thump any rivet counters that pointed it out. But I'm inclined to bin the casting, update the 3D CAD model and create the lettering on the CNC mill.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 19, 2018, 11:24:42 AM
The perch brackets are now fitted to the smokeboxes. I first tried drilling by hand, but that proved to be a fudge too far. So I reverted to using the milling machine:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Perch_Bracket_Fitting_1.JPG)

The smokebox is clamped to an angle plate and an angle of dangle meter used to set the drilled surface of the casting roughly horizontal. Top middle right the small protrusion from the perch bracket is a bar with a small spigot on the end. The spigot engages with a hole in the smokebox to help alignment. Afterwards the hole is tapped and a screw fitted. I can then remove the screw and use the hole to oil the bracket that holds the front axle. To align the drill with the existing holes in the casting I used my ears. You can hear a 2-flute catching the edge of the hole when the quill is lowered. As the table is moved this changes to a swish as the drill enters the hole cleanly. Doing this in X and Y is quite quick and achieves an accuracy that is acceptable in this application. I spotted the smokebox using a 1/4" drill followed by a tapping drill for 1/4" BSF. Before moving clamps the holes were partially tapped to ensure alignment. Final tapping was done afterwards with the perch bracket removed. Here's the final assembly:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Perch_Bracket_Fitting_2.JPG)

The homemade studs were individually adjusted to allow for varying casting thicknesses so that the same number of threads show above each nut. I couldn't find a new 1/4" BSF die (probably didn't buy one as I use a Coventry diehead for making the studs) so I used an old one marked AM (Air Ministry) and 1940. No doubt it is carbon steel, and had a chip or two, but it still worked fine.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 26, 2018, 11:38:07 PM
But I'm inclined to bin the casting, update the 3D CAD model and create the lettering on the CNC mill.

Which is what I did! I spent ages creating a CAD model and generating CAM files. Then someone on another forum kindly sent me detailed pictures of the front end of a full size SCC engine. Which showed that my lettering and size was completely wrong, so I binned all my CAD and CAM files. However, I simply couldn't get all the proper lettering to fit. Then I noticed that the font on the full size engine is very narrow, it looks quite odd. So presumably the original pattern makers had the same problem. I didn't have access to a narrow enough font, but by creating individual parts for each letter I was able to scale each letter in width only. And then I could create an assembly with the correct width lettering. I had some real problems getting the assembly into the CAM program. My CAD program won't generate IGES files from an assembly, and my CAM program gets scaling wrong with STEP files. In the end I called the UK agent for my CAD program and their technical guru ran me through a procedure to convert an assembly into a single non-editable part. But not before I'd lost all my work when the CAD program overwrote everything.  :(

Today I've been playing with the final tweaks to the CAD and CAM and running the CNC mill. Here's the prototype nameplate ring in a piece of scrap alumimium from a client project:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Inner_Nameplate_1.JPG)

I spent quite a while thinking about fixtures and turning the ring concentric with the CNC milled lettering. But by CNCing the inner and outer circles on the ring the fixture for the final rings in brass was very simple:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Inner_Nameplate_2.JPG)

And the final two rings in CZ120, engraving brass:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Inner_Nameplate_3.JPG)

The thickness at the bottom of the circles varies from 0.15mm to zero, so I should be able to break out the rings fairly easily. All milling was done with a 1mm cutter running at 350mm/min and 24000rpm with a step down of 0.2mm per step. The depth of the engraving is 0.635mm (25 thou). Machining time per ring was about 1 hour 20 minutes.

Next job is to machine the central cast iron boss in which the brass rings are embedded, as per this CAD assembly:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Inner_Nameplate_4.jpg)

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: zeeprogrammer on August 26, 2018, 11:43:33 PM
They look great!  :ThumbsUp:

It does make one think about CNC.
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Kim on August 27, 2018, 05:13:18 AM
Andrew,
That was a lot of work but the finished product certainly makes it all look worth while!
Kim
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: deltatango on August 27, 2018, 06:28:25 AM
That was a big effort Andrew! Was Alibre playing up? One hour 20 sounds quick to me.

Regards, David
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jasonb on August 27, 2018, 07:21:34 AM
They look good Andrew, should be even nicer with some red paint flowed in to cover the tool marks which should show off the lettering even more.
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 27, 2018, 10:01:34 AM
Thanks for the kind words. I had some issues with Alibre, primarily when converting an assembly to a part. The first time I did it all my files got overwritten with non-editable versions. After talking to the UK distributor I clicked the tickbox that said save the part file to a separate location. Simple, but not obvious when you don't know. The lettering is rather better than on the full size engine! But of course the original builders didn't have CNC available.  ;D

Given that the smokebox is going to get hot I'll probably paint both inner and outer nameplates with the same high temperature black paint that I use for the smokebox proper. That seems to be in accordance with the pictures I've been sent of a full size engine. Although it's difficult to tell what's paint and what's grime!

I'm itching to start machining the central boss, but I have to go out soon to do an aircraft inspection. Followed by a stint as afternoon tug pilot. It's going to be quiet looking at the weather; flyable but not really soarable.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 31, 2018, 09:28:13 PM
The central bosses are now made:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Smokebox_Door_6.JPG)

Actually I made three due to a foul up on the dimension of the inner diameter of the groove on the second one. I made a thin steel ring and loctited it in place to compensate. But I wasn't very happy with it, especially as the smokebox will be getting hot, so I made another one. Fortunately I didn't have to buy more material. The lengths of cast iron I have for the cylinder liners are longer than the liners as it assumed the pistons are cut from them. Since I made my own pistons to a home brew design I had metal to spare. The HP liner was just right. The groove for the nameplate ring is very slightly (a couple of thou) oversize. The last thing I want to do is push the ring into place, and not be able to get it out again!

I'm now getting niggled by the dots around the word BURRELL on the outername plate instead of proper quote marks. I'm thinking of CNCing some quotes and somehow fixing them in place of the dots. Sadly the NHS (National Health Service) has said it won't offer therapy for this annoying affliction of wanting everything just so.  :(

On another matter I decided I didn't like the studs holding the perch bracket onto the smokebox, so I made some bolts instead:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Perch_Bracket_Fitting_3.JPG)

The rationale is that I have several pictures of fullsize engines and three use bolts while only one uses studs and nuts. Bolts are going to be a darn sight easier to remove. And I can see the perch bracket coming on and off a few times during the build.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jasonb on September 01, 2018, 07:06:29 AM
Looks good andrew and fixing those inverted commas will be good silver soldering practice. If you don't fancy soldering then drill and tap a hole, CSK the rear and make a GM screw that you can then CNC the bit sticking out the front to shape.

J

You now just need to get over the fact that the inner and outer rings are different colour copper alloys :LittleDevil:
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on September 01, 2018, 08:22:03 PM
If I make the quote marks I'll make them as a pair separately and then fix the block with a countersunk screw from the back.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on November 27, 2018, 09:48:40 PM
The last few months have disappeared in a Kafkaesque tale of trying to get a bathroom and kitchen refurbished; and this is still an ongoing task.  :(  However, I have made some progress on my engines. I've been working on the hinge for the smokebox door. This needed completely redesigning, as originally drawn it would have never fitted together. A member of another forum has kindly sent me lots of pictures of a full size example of the engines, so I'm trying to follow that as best I can.

Once designed the hinges are fairly straightforward machining, from lumps of hot rolled steel. The hole for the hinge pin was drilled from each end, just deep enough to clear the hinge joints. When drilling the holes I used a fixture consisting of two angle plates clamped to the mill table to give a repeatable location and to ensure the embryo hinge was precisely vertical. Just for interest I formed the curves on the hinges using a form cutter on the horizontal mill. It worked rather well:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Hinges_MEM_1.JPG)

Here are the finished hinges. They sit in a recess machined in the smokebox door. The design incorporates 5 rivets as per full size rather than the 4 shown on the drawing. Note also the small fillets at each end across the fingers where the hinge pivots will fit. I don't know what purpose they serve, but they're on the full size engine. The rivet holes in the door and hinge were drilled separately, so it's pleasing all the rivets fit with just a light tap from a tack hammer:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Hinges_MEM_2.JPG)

The hinge pivots turned out to be a right royal PITA. I made a set from hot rolled steel. No problem until I came to cut the 2BA thread on the bottom. The threads were awful with the crests torn and incomplete. I tried a number of fixes, including buying a new die. Nothing worked, darn it can't even cut a 2BA thread.  :embarassed:

After a suitable sulk time I made another set in EN1A; no problems threading this time round. Each pivot was fine tuned to its position as the orientation of the threads in the smokebox ring are random:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Hinges_MEM_3.JPG)

Finally here is the hinge assembled:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Hinges_MEM_4.JPG)

The hinge pin goes in mostly with a firm push by hand. In a couple of places I can just get a 1 thou shim between the door and ring. The shim is gripped by applying light pressure. That's much better than I was expecting, and indicates I should have no problem getting an air tight seal on the door.

Next exercise is to make the dart and locking arrangement for the door.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on March 29, 2019, 07:32:28 PM
I have been somewhat distracted recently dealing with builders, double glazers and kitchen companies in order to get a new kitchen fitted. I've also had to do a lot of painting and sorting out the issues left undone by the workmen. Over two months without a kitchen is tough - there are only so many cans of soup you can eat in a row. However, I did get the locking mechanism fitted to the smokebox door, and the smokeboxes fitted to the boilers before Christmas. Here are the component parts:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Smokebox_1.JPG)

Although loosely based on the drawings I have changed quite a lot of the internals to give a proper, symmetric, locking mechanism and I have tried to scale the external parts from pictures of a full size engine. The square hole in one of the locking handles was filed by hand, just for the hell of using old school techniques. The parts fit together nicely and the locking is positive and firm:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Smokebox_2.JPG)

Having shown this picture on another forum an error was pointed out. The outer, locking, handle should lock before 6 o'clock, not after, so vibration doesn't loosen it. A bit of quick work with a file sorted that out. I dithered about how to fit the smokebox to the boiler; make a fudge up and that's 1500 quids worth of boiler up the spout. Measurements were made, double and then triple checked. I didn't fancy driling holes through 3/8" steel with a portable drill - too easy to go skew whiff. I needed little incentive to splash out on a mag drill and tube mounting accessory:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Smokebox_3.JPG)

The smokebox was aligned by setting an electronic angle meter to zero across the top of the hornplates and then getting the reading to zero again by moving the smokebox assembly with the meter sitting across the top of the chimney base. In order to get to the underside of the smokebox I had to remove a lot of parts at the back and sit the  boiler and smokebox vertical. Quite a lift on ones tod, glad they weren't any heavier. With the boilers vertical it wasn't easy to get the mag drill clamped in the right place while supporting its weight and getting the drill bit lined up with the existing hole. It took sweat, some tears and a lot of swear words. This shows the boilers with smokeboxes fully fitted, plus the front wheel axles:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Smokebox_4.JPG)

Just for reference this is a picture taken in the same place, but with the new kitchen installed:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Kitchen_1.JPG)

Notice a difference? No engines! The boilers are in the hall, the machined parts and work in progress in the sitting room and the castings in the study.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on March 29, 2019, 08:59:09 PM
Prior to fitting the spokes to the remaining two rear wheels I need to fit the strakes around the rim. The strakes were machined, drilled and countersunk months ago from flat bar. The issue is how to bend them to fit the rim. They need to be curved along the short side, as well as following a helix on the long side. The "normal" ways of using bending rolls or twisting in a vice didn't work for me. In retrospect I could have rolled some flat sheet of the appropriate width and cut the strakes from that on the skew. Although I have been advised that it's a serious amount of work to cut and clean up all the strakes. Given that I l already had flat strakes how to form them? I've seen a Dutch website where they hot pressed the strakes. That seemed like a reasonable way to go, and better yet it's not something I've done before. I started making the press tools by cleaning up some hot rolled steel. That gave me the chance to use one of the slab mills I bought years ago via Fleabay. The slab mill is 4" x 4" running at 88rpm, DOC of 2.5mm, WOC of 32mm and feedrate of 160mm/minute, a bit under 0.1mm chip load, lots of swarf and steam:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Strakes_1.JPG)

It's a UK built mill (Adcock & Shipley) but a US made vice.  :ThumbsUp:

I've still got a lot to learn about driving the horizontal mill hard, and even more about clamping the work. I tried doubling the DOC but the cutter pulled the work out of the vice, and then carried on as if nowt had happened but with a much bigger DOC! The curves on the press tooling were done on the CNC mill using a 10mm ballnose cutter. Initial scallop depth was 0.05mm. Here are the press tools fitted on the flypress:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Strakes_2.JPG)

As expected trying a strake cold simply resulting in the strake springing back with no forming. So I tried one red hot (800C). That worked well but there were two issues. I'd made the press tool radius a couple of inches smaller than the wheel rim in the hope that the outer edges of the strake would touch first and then the middle of the strake would be pulled down by the rivets. It turned out I needed to decrease the radius by a bit more. Second the scalloping on the press tool marked the work, despite some judicious filing after machining. So I tweaked the CAD model, redid the CAM and also set the scallop depth to 0.01mm. These parameters resulted in a nicely formed strake:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Strakes_3.JPG)

Although not obvious the strake is curved along the short edge, by about 10 thou, as well as having the pronounced helix. The strake is a fair fit on the wheel rim:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Strakes_4.JPG)

And also along the short edge:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Strakes_5.JPG)

The fit is pretty good considering that the wheel rim is less than perfect due to weld distortion.

I'm probably going to run with this, and acknowledge that each strake may require a bit of hand tweaking. I've done some searches, but haven't found anything to indicate how full size strakes were formed. Possibly something similar but with a blacksmith and anvil?

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Dave Otto on March 30, 2019, 12:01:44 AM
Nice work Andrew and the new kitchen looks great!

Dave
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on March 30, 2019, 10:51:43 AM
Thanks Dave, I try to do nice work, even if I don't always suceed.

I'm pleased with the new kitchen. Even I would admit that the old one was getting very grubby and starting to fall apart. The worst aspect was tiled worktops which, along with the slightly porous finish on the cupboards, was impossible to keep clean. I told the kitchen people that the number one, two and three priorities were easy clean!

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Kim on March 30, 2019, 04:57:44 PM
Wow! Those took up most of your kitchen!  Are you going to move them back into the kitchen now that it's finished?
Kim
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on March 30, 2019, 08:31:02 PM
Are you going to move them back into the kitchen now that it's finished?

I'm afraid not, I've been banned from putting them in the kitchen. And if you'd met my mum you'd know it's not worth arguing if you want a quiet life.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Admiral_dk on March 30, 2019, 08:37:00 PM
Nice work all the way round Andrew  :cheers:
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jo on March 31, 2019, 09:03:36 AM
Are you going to move them back into the kitchen now that it's finished?

I'm afraid not, I've been banned from putting them in the kitchen. And if you'd met my mum you'd know it's not worth arguing if you want a quiet life.

Andrew

:lolb:

You are not the worst I know of: ilvaporista's brother Dave had his Bridgeport milling machine in his kitchen  :naughty: and the chips would get everywhere  :LittleDevil: In the end his sister-in-law refused to visit and finally his Mum made him move it out :-\

Jo
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on March 31, 2019, 10:33:36 AM
Nice work all the way round Andrew  :cheers:

Thank you.

In the round is my next issue. When I fit the strakes I need to predrill one hole per strake. I see two options; one, step round the circumference with dividers, making adjustments until I get back to where I started, as I did when fitting the spokes. Or two, mount the rim on the rotary table and drill each hole using the rotary table to index. I'm leaning towards the latter, as there are 36 strakes and the rim isn't perfectly round, so I suspect using dividers will end with me chasing my own tail.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on March 31, 2019, 10:38:53 AM
had his Bridgeport milling machine in his kitchen

How on earth did he get it in there without a lot of dismantling/

It wouldn't suit me though. For a start I'd need to run a 3-phase extension lead from the garage. And a lot of the tooling is shared with my my other two mills, so I'd be traipsing back and forth like a yo-yo. Not only that I can just lift the dividing head from the shelf to the machine table. No way I'd be carrying it all the way from the garage to the kitchen; or if I did it would be followed by a trip to A&E.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jo on March 31, 2019, 11:22:07 AM
How on earth did he get it in there without a lot of dismantling/

You only need to rotate the head down and slide off the table  :-X

Quote

It wouldn't suit me though. For a start I'd need to run a 3-phase extension lead from the garage. And a lot of the tooling is shared with my my other two mills, so I'd be traipsing back and forth like a yo-yo. Not only that I can just lift the dividing head from the shelf to the machine table. No way I'd be carrying it all the way from the garage to the kitchen; or if I did it would be followed by a trip to A&E.

Sounds like you have thought about this before  :lolb: I would recommend one of my rollerskates for moving around and lifting tooling on and off the machine beds  :ThumbsUp:

Jo
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on May 09, 2019, 11:01:47 PM
I've made some more progress on the rear wheels with strakes. I chose to drill the first row of holes for the strakes in the rims using a fudge setup on the rotary table involving some hot rolled steel bar and the right-angle attachment for the Bridgeport:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Rear_Wheel_5.JPG)

I decided this would be more accurate, and quicker, than stepping round with dividers. With 36 strakes even a small error in the dividers would accumulate to an unacceptable degree. I'm not a fan of centre drills, but in this application the stub length and hence stiffness combined with the less than perfect surface was useful.

Before forming the strakes for real I altered the arrangement of the fences:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Strakes_6.JPG)

The new arrangement means that there is a closed corner in which to place the red hot strake. This makes it much easier to quickly place the strake before forming. This allowed me to place the strake, form it, turn it round and operate the flypress again before the strake lost its red heat. I managed to drop a couple of red hot strakes; good job my floor is concrete. Fitting each strake required a slight unbending of the helix (adjustable spanner and vice). Once fitted the strake was set to the correct angle and a second hole drilled using the Bridgeport set at a jaunty angle. Lining up was done by hand and no clamping of the rim was needed, it's pretty heavy:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Strakes_7.JPG)

Here is the wheel with all strakes in place. Before taking the picture I checked that the strakes were in the correct sequence. Namely four rivets, one plain hole left, four rivets, one plain hole right and repeat. I discovered that I'd got a couple of strakes in the wrong order. Correction was simply a case of turning the offending strakes around. The drilled holes lined up perfectly; that's the beauty of CNC drilling the holes in the strakes. The plain holes will eventually be opened out for "bolts" to hold the anchors (spuds) for soft ground or for fitting frost spikes:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Strakes_8.JPG)

I'm quite pleased with the fit of the strakes, although might do some final tweaks as I fit and form the rivets:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Strakes_9.JPG)

Before fitting the strakes I spent a duff weather weekend at the gliding club angle grinding the welds on both rims into shape and cleaning up with flap wheels. I did this at the gliding club as I have new neighbours and I didn't think they'd appreciate many hours of noise in what is a quiet rural area. Well at least not until they've got used to the idea of the nut next door with a workshop. I also put a fillet of U-Pol Easy on the welds. I thought I'd been quite economical with the filler, but it still took hours to sand it down. Next job is to experiment on some scrap with rivet length and then close a lot of rivets! I might leave the rivets outstanding once closed as per full size; it being assumed that initial running would wear the rivets down to a smooth fit with the strakes. The second set of strakes have been hot formed, so I can break down the setup on the flypress and set up for riveting. And yes, I did remember to move the fences so that the second set of strakes were formed with the opposite hand to the first set.

Last weekend for the first time I assembled parts into an engine that sits on its own four wheels:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Engine_1.JPG)

My first reaction is **** me, that's big! And that's without the tender on the back. Good job I moved out of the kitchen; the engine is too wide to go through the door. I had a panic about getting the engine out of the house, but fortunately I specified my newish front door such that it's an inch or two wider than the engine.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Kim on May 10, 2019, 12:15:13 AM
That's IS big!  That's what I've been saying (almost every time I post to your thread! :)).
Nice work on the strakes, they look great!
Kim
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: crueby on May 10, 2019, 12:27:16 AM
... I had a panic about getting the engine out of the house....
Had the same thoughts partway through a canoe project... measured the openings about 10 times...

Those wheels are looking great - very well done!   :popcorn:
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jasonb on May 10, 2019, 07:09:55 AM
Looks good Andrew though you may want to consider flushing up the rivit heads before you roll the other engine onto your laminate floor, I know which material will wear first :-[
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on May 10, 2019, 11:52:58 AM
That's IS big!

Of course I've been aware that it's definitely not a mantlepiece model. But having assembled it my jaw hit the floor; it brings it home that it really is BIG! Gawd knows where I'm going to put the second engine.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on May 10, 2019, 11:55:51 AM
you may want to consider flushing up the rivit heads before you roll the other engine onto your laminate floor

Not too worried about that. The floor is el cheapo B&Q plastic wood. It already has quite a few gouges and lumps knocked out of it as a consequence of heavy engineering and assorted builders traipsing through the hall.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on June 29, 2019, 12:19:54 PM
Now that I've chucked in my job and joined the band of the great unwashed, aka the unemployed, I'm hoping to have more time for flying, gardening and workshop.  ;D

The strakes have now all been riveted, by hand in small batches in deference to the neighbours, and the hammer marks, :embarassed:, cleaned up with an angle grinder and power drill with a coarse flapwheel:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Strakes_10.JPG)

The zig-zag pattern of larger holes are for anchors (aka spuds) and frost spikes. The anchors are made from metric angle, 30x30x5. As expected a cold bending test resulted in the metal cracking. So the ends were bent hot using a home made fixture to form the design radius and an oxy-acetylene cutting nozzle to supply heat:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Anchors_1.JPG)

Just remember not to activate the cutting oxygen handle! The anchors are deliberately left a bit rough in view of the fact that in full size they would have been forged by the blacksmith:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Anchors_2.JPG)

Here's an anchor in place; I still need to drill the fixing holes:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Anchors_3.JPG)

The distance from the wheel edge to the fixing holes varies around the wheel rim. In full size this was accomodated by drilling an oversize hole in the anchor. I'm going to copy that.  :ThumbsUp:  I've also churned out the anchor bolts and frost spikes. All done on the repetition lathe except for the tapered end of the frost spikes done on the centre lathe using the top slide and one pass. The rounded tip was formed with a file:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Anchors_4.JPG)

As well as drilling the holes in the anchors I also need to make rectangular slots in the bolts and spikes for the retaining keys. I'm proposing to drill/mill the slots on the CNC mill and use a keyway broach to square up the ends.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jo on June 29, 2019, 12:25:24 PM
That photo makes the wheels look a lot smaller than they really are  :thinking:

Now that I've chucked in my job and joined the band of the great unwashed, aka the unemployed, I'm hoping to have more time for flying, gardening and workshop.  ;D

So are you officially now retired  Andrew or still considering looking for paid work  ::) ?

Jo
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on June 29, 2019, 10:06:49 PM
So are you officially now retired.........

Sadly not, but as one of the other engineers said the company was a bit broken at senior level. Actually that's not true, it's a lot broken! So it was time to leave. I wasn't the first to go and I haven't been the last.

Immediately after I resigned the company asked if I'd be willing to go back as a subbie in the future. Fine by me, go in, do the work, get paid and no need to get involved in company politics. I've got a couple of weeks self-employment to do now. There's a good chance we can sell another couple of small jobs over the next few months as well. And a few other projects and ideas are simmering in the background. We'll see what happens over the next few months. If the worst comes to the worst I can always look for another job. In  the meantime it's gliding, gardening and workshop, but not necessarily in that order.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on June 30, 2019, 07:27:57 PM
Enjoy your "Freedom"" while you can Andrew :cheers:              Engine is coming along nicely.        Terry
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on July 01, 2019, 11:45:19 AM
I intend to, but already one week in and I'm overbooked; too many things I want/need to do and not enough time.  :'(

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: scc on July 01, 2019, 09:55:28 PM
I intend to, but already one week in and I'm overbooked; too many things I want/need to do and not enough time.  :'(

Andrew

Sounds just like retirement  :Lol:           Terry
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on July 13, 2019, 07:27:54 PM
The holes in the anchors have now been drilled to allow them to fit to the wheels. I used calipers to measure the distance, in millimetres, from the wheel rim to one side of the holes drilled in the strakes. I then took the average of the smallest and largest distance. To that I added the radius of the hole in the strakes and one millimetre for good measure, and to account for the fact that internal radii in the ends of the anchors are finite. A key part was noticing that on the Burrell wheel drawing in the book by Gilbert the shank of the anchor bolt is given as 1-1/8" whereas the hole in the anchor is 1-1/4". Scaling down that gives 3/8" for the hole in the strake and 27/64" for the hole in the anchor. The anchors are quite a nice fit. This picture shows an anchor in position:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Anchors_5.JPG)

The anchors can pivot, but given that the reaction to the wheel torque is into the picture, and the anchor pivot point is not symmetric the result will be to force the anchor into the fully back position.

The anchor bolts and frost spikes are also finished with rectangular slots cut for keys that will hold them in place:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Anchors_6.JPG)

There are 18 anchor bolts and 36 frost spikes, so clearly a job for the CNC mill. It's tempting to say I used a square drill. But they're unobtainium, and the normal method of drilling a square hole isn't really suited to a slot that is only 1/8" wide. So instead I drilled three 3mm holes with a carbide drill (time 10 seconds) and used a 3mm carbide end mill to open out the slot (time 2 minutes) albeit with round ends:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Anchors_7.JPG)

To form the square ends I used a 1/8" keyway broach. The broach was thinned on the surface grinder, half a thou at a time, until it was a nice fit in the pre-existing slot. An arbor press was used to push the broach using a 1/8" drill as a spacer and shims as required to get a nice square end. I had some problems keeping the broach vertical as, at best, only two teeth are in contact at a time. The work is resting on two lengths of nominally 1/8" keyway steel held in place with double sided tape:

(http://listerengine.com/coppermine/albums/userpics/10022/normal_Anchors_8.JPG)

It's quite possible that the original items were made in the blacksmith shop, so my parts are a least a bit better than that!

Nest job is to design and make the curved keys that will keep the bolts and spikes in place.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: crueby on July 13, 2019, 07:41:18 PM
Are the anchors like a paddle on the rim of the wheel, for traction in mud?
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on July 13, 2019, 08:38:32 PM
Are the anchors like a paddle on the rim of the wheel, for traction in mud?

Correct, also known as spuds. Some manufacturers used T-section but for some reason, probably cost, Burrell used angle.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on July 28, 2019, 11:22:13 AM
To complete the anchors and frost spikes I have designed some curved tapered keys:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Anchors_9.JPG)

Initially I printed a 1:1 drawing of the key and made a card model to check fit. That being satisfactory I made a batch of 36, plus a few spares. The holes were drilled on the vertical mill (three cheers for DROs) and the holes then used to hold the blank on the CNC mill for profiling. The keys are a snug fit in the anchor bolts and frost spikes:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Anchors_10.JPG)

In general the keys lock only part way in, to allow for wear on the strakes and the slots in the bolts and spikes.

While I need to extract my digit and finish off the remaining two rear wheels I'm keen to get some motion work built and installed on the engines. To that end I've been machining the crosshead castings, making some changes so they are more prototypical. My tug pilot duty has been cancelled today as it's wet; even the ducks are walking. I plan to make a start on the slidebars and make the castellated nuts for the conrod little end bolts. I also need to order a 20 tpi Whitworth insert so I can screwcut the 3/8" BSF thread on the end of the bolt. I'm pretty sure I've got some 1/2" silver steel (aka drill rod) but if not I'll order that too.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Kim on July 28, 2019, 02:56:19 PM
That's quite a pile of little tapered keys!  They sure look nice in place.

Would they use cotter pins (or split pins :)) to keep the keys from falling out in use?

Kim
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on July 28, 2019, 09:00:50 PM
Would they use cotter pins (or split pins :)) to keep the keys from falling out in use?

I don't exactly know. But I'm sure pins of some sort would have been used to ensure that the key wasn't lost if it came loose. There seems to be a lack of information about the whole area of anchors and frost spikes. I suppose they're not much used these days, even by the fullsize engines.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on July 28, 2019, 09:20:38 PM
My tug pilot duty has been cancelled today as it's wet; even the ducks are walking. I plan to make a start on the slidebars and make the castellated nuts for the conrod little end bolts.

Simple but satisfying, just right for a wet Sunday afternoon; even if I did nearly do myself a mischief lifting the dividing head onto the milling machine table to mill the hexagon and cut the slots:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Crosshead_1.JPG)

The slidebars are also roughed out from gauge plate:

(http://lister-engine.com/coppermine/albums/userpics/10022/normal_Crosshead_2.JPG)

The drawings call for 3/8" x 3/4" for the slidebars. But rectangular gauge plate isn't normally ground on the short dimension, so I started with 20mm x 10mm stock. I can live with the 10mm dimension but reduced the 20mm width to 3/4" to get a nice machined surface.

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jo on July 28, 2019, 09:25:02 PM
. even if I did nearly do myself a mischief lifting the dividing head onto the milling machine table to mill the hexagon and cut the slots:

A nice little hydraulic roller skate will prevent these little aches and pains  ::)

Jo
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: deltatango on July 29, 2019, 12:44:34 PM
It's good to see the progress. Those wheels are impressive!
I can't imagine the local Council being very impressed with the effect of the ice spikes on their bitumen...

Will you be showing any of the bits at Forncett this year?

David
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 04, 2019, 08:07:13 AM
Will you be showing any of the bits at Forncett this year?

Yes, that's the plan. I've sent my application form off, although I haven't had confirmation. That seems normal these days, so I intend to just turn up on the day. I hope to exhibit a completed wheel with strakes, plus the anchors, frost spikes and ancillaries. Also the crossheads and slidebars and possibly a few old favourites.

Andrew

PS: Given the poor state of the roads around here I doubt the council would notice any effect from the frost spikes!
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: tangler on August 04, 2019, 04:41:28 PM
Will you be showing any of the bits at Forncett this year?

Yes, that's the plan.

Good, I shall look forward to that.

Rod
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: deltatango on August 04, 2019, 11:00:33 PM
I'm looking forward to seeing them!
DT
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 05, 2019, 11:30:37 AM
Oeeeer, better get my finger out and ensure I've got something new to show!

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: deltatango on August 05, 2019, 12:23:15 PM
No pressure of course... :)
DT
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: jadge on August 09, 2019, 09:55:49 PM
I've been assembling a wheel today; it's not going to plan and is painfully slow. My excuse is that I haven't been well recently. At least I remembered to drill the driving pin holes in these wheel hubs before assembly. It's going to blow a hoolie tomorrow so I hope to get one wheel completely spoked up. Just under two months to go!

Andrew
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: cnr6400 on August 09, 2019, 10:47:03 PM
Blow a hoolie? no idea what that is.  :shrug:

 Good luck with the wheel.
Title: Re: Burrell Single Crank Compound Traction Engines - 4" Scale
Post by: Jo on August 10, 2019, 06:27:54 AM
Blow a hoolie? no idea what that is.  :shrug:

Tis named after the hooley which is a wild and noisy Irish dance... So blowing a hooley (or hoolie) is a wild and noisy wind.



Making traction engine wheels is riveting stuff  :lolb:

Jo