Author Topic: Reinventing the Real.  (Read 5582 times)

Online Jasonb

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Reinventing the Real.
« on: May 21, 2022, 07:05:41 PM »
While making the Stuart Victoria last year I started to feel like I would also like to make the Real to go with it. So I bought Andrew Smith's book (cheapest source of drawings) on building the Real and started to look a pictures of them on the net, the more I looked the more I saw that I did not like and that included what Stuarts are asking for the kit. So over a few winter evenings I developed a different version that has gone by the working tile "Unreal" which addresses some of these issues and also more closely follows the etching from Andrew's book that was his inspiration.



Although I could have made the flywheel and cylinder from scratch I decided to use just these two Stuart castings as I felt that others who may want to follow suit would find these the most difficult parts to make from scratch. I also went for a metric design based on nominal sizes rather than direct conversion of the old imperial sizes again with many beginners now of an age where they were taught metric at school that make sense and if using handwheels on modern metric machine sit is easier to keep track of whole metric numbers rather than working to several significant figure after the decimal point. This results in a model with 25mm bore and 50mm stroke

I'll go into more detail during the build about the various modifications but a summary is as follows

Base - This is a very expensive casting at £45 for what is little more than a rectangle with tapered sides and rounded corners So something with a bit more shape and detail
Columns - Again something with more shape and detail than the plain tapered ones
Entablature - This is shaped the wrong way for any form of classic architecture being larger at the bottom than the top all for the sake of easy removal from the sand so that needs to be corrected and some additional detail added at the same time
Pulley - change for one closer to the one shown in Andrew's book not the standard Stuart one used on all their 2 x 1 models
Flywheel - remove the "lumps" they now cast on the rim, add some counterbalance weight and fit with a gib head key
Valve/eccentric - modify layout to do away with the dog legged valve rod and make an eccentric correctly shaped for vertical use
Cylinder - move exhaust position as it gets a bit tight between column and exhaust position
Crosshead and guides - change to rod guides which was another feature of the engraving in Andrews Book.
Conrod - change from the tuning fork design to one similar to the other 2 x 1 Stuarts and Andrew's etchings

On the cost front this model work out at about £200 which is half of what Stuarts are currently asking. This is based on buying most materials by the 300mm length so you will have some over for the next engine. Larger diameters by the 25mm length where available. The cost also includes enough for fixings etc as well as the price of the two castings.

A few more bits of tooling and cutters may be needed but those will last a long time and if used over several more models will not amount to much. I did make use of my CNC for some of the parts but just about all could be done with manual machines and only one part would need a bit more of a redesign to make it a bit easier to cut from solid.

Next time I'll start on the construction of the base. And don't worry as unlike the Wall engine this one is finished and runs very well so there will be a happy ending to the build.
« Last Edit: May 21, 2022, 07:09:29 PM by Jasonb »

Online crueby

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Re: Reinventing the Real.
« Reply #1 on: May 21, 2022, 07:40:16 PM »
Nice proportions on that! Looking forward to seeing this one develop...

Online Jo

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Re: Reinventing the Real.
« Reply #2 on: May 21, 2022, 09:30:47 PM »
The Real engine is rather nice  :embarassed:



Jo
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Offline samc88

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Re: Reinventing the Real.
« Reply #3 on: May 21, 2022, 09:43:31 PM »
Thus sounds great, I shall be keenly following along

Sent from my SM-A127F using Tapatalk


Offline 10KPete

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Re: Reinventing the Real.
« Reply #4 on: May 21, 2022, 11:47:59 PM »
That's quite the impressive engine, Jo! What was it powering?
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Online Jo

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Re: Reinventing the Real.
« Reply #5 on: May 22, 2022, 06:34:40 AM »
It used to run a Mill and Mash drive  :DrinkPint:

Originally built in 1829 by H & W Davis of Landport and she worked in Fareham Brewery until 1952. She is now at the "Stretham Old Engine" museum in Cambridgeshire  ;)

Jo
« Last Edit: May 22, 2022, 06:51:13 AM by Jo »
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Online Jasonb

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Re: Reinventing the Real.
« Reply #6 on: May 22, 2022, 07:06:15 AM »
Though not "the Real" engine that Andrew Smith used as his inspiration it is just one of many true (crank at the top) engines and like the engraving he used has (had) one end of the crankshaft supported in the building's wall.

I did not go as far as making it two columns and a wall as there are a couple of other engines on my to do list that will be made that way, this Thomas Rose being top of the list. I also wanted to keep the general feel and simplicity of the Stuart Real in this instant rather than make a scale model of a specific engine.

In the last image you can see the engraving he used as well as his own engine that had the larger dia pully.

« Last Edit: May 22, 2022, 07:14:51 AM by Jasonb »

Online Jo

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Re: Reinventing the Real.
« Reply #7 on: May 22, 2022, 07:49:28 AM »
The guys in SIMEC like Andrew did some interesting things back in the 1970s with their "reuse of Stuart Turner Castings". I haven't read the book but the Stuart Turner website points at the Fareham Overcrank Engine as its claim for the original and it is rather nice  :embarassed:

The Stuart model Real design is a pretty little thing, especially when it is in motion  :)

Jo

P.S. Surus has just shown me he has some Overcrank Engine Castings  :pinkelephant:
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Online Jasonb

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Re: Reinventing the Real.
« Reply #8 on: May 22, 2022, 10:13:44 AM »
They just use that image as an example of a "real" or "true" vertical http://stuartturnersteam.com/6Pack/Real/Real.html

It would be resonably easy to replicate, the crank and piston rod guide are very similar to the Benson as it the governor. Columns just smaller versions of the Otto Langen so just milling and dividing and the entablature with it's pediment can be milled from 2 or 3 bits of bar, look forward to seeing your rendition Jo. :stickpoke:

Offline RReid

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Re: Reinventing the Real.
« Reply #9 on: May 22, 2022, 02:51:36 PM »
I can definitely see the appeal. There is an elegant simplicity to those over-crank engines. Watching with interest!
Regards,
Ron

Offline Michael S.

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Re: Reinventing the Real.
« Reply #10 on: May 22, 2022, 05:15:44 PM »
This is going to be a very nice model. I love those old designs where the crankshaft is on top of the cylinder. One of my first models was built in a similar way. Another one made of cast parts was added later.
But I always found the Stuart machine very interesting.
I have here two more views from a physics book from 1858. Also a nice construction.
I look forward to pictures of the making of the machine.

Michael

Offline 10KPete

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Re: Reinventing the Real.
« Reply #11 on: May 22, 2022, 06:35:39 PM »
Thanks, Jo. These older engine designs are very interesting and lovely to look at.

Pete
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Offline steam guy willy

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Re: Reinventing the Real.
« Reply #12 on: May 23, 2022, 02:41:35 AM »
Hi "J" , this looks like an interesting project and I will be following with interest.
"W"

Online Jasonb

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Re: Reinventing the Real.
« Reply #13 on: May 23, 2022, 06:58:56 PM »
I decided to make a start with the flywheel while I was waiting for a delivery of materials that would have allowed my to start with the more logical base. You seem to read a lot that the current Stuart castings are not what they used to be but I have to say that both the flywheel and cylinder castings were very good - No holes, no hard spots, mould halves lined up with no step and very little flash. The only real downside is that Stuarts seem to only supply castings from the pattern used for the twin Victoria which have the ugly bosses cast in where two flywheels are bolted together.



I like to fettle my castings before machining so there is no risk of spoiling any finished surface if you slip with a file or grinder so that was the first thing to do. As the inner rim is not machined I like to set that to run true and was able to do so by holding in the 3-jaw. This allowed me to turn the outer surface, one side, clean up the hub and also bore the hole all at one setting. I like to bore the hole to finished size as a reamer is likely to follow a drill hole that may have wandered and I can also get a slightly closer fit than a typical reamer will give which reduces the chance of a wonky flywheel. Once I got close to size by measuring with the digital callipers I switched to using a piece of the crankshaft material as a plug gauge to get the final size.



I did the outside with the lathe running in reverse and used a boring bar mounted upside down which easily reached around the casting with minimal overhang



I then changed to the 4-jaw and set the machined surfaces to run true using one indicator on the OD and another against the side.



It was then a simple job to turn the other face and clean up the hub.



You can see where I have turned away the bosses that there are some flattish areas these were blended in with a Dremel using an oval shaped grinding point.

Stuart show a grub screw to retain the flywheel but I used a broach to cut a tapered keyway and machined up a suitable gib head key from gauge plate to fit.



Jumping ahead to when I test ran the engine it was quite noticeable when running slowly with no load that the engine rotated faster when the crank was moving downwards than up which is due to the added weight of the conrod, crosshead, piston and piston rod all pulling downwards and then the engine having to work harder to lift that weight back up again. So some strips of lead flashing were cut and bent to the curve of the inner flywheel and held in place with masking take to experiment with how much counterweight needed to be added. Once happy the two layers of Code 4 lead were bonded in place with JBWeld. Once hardened the excess JBW was cleaned up, a bit more U-Pol filler added to blend things in and you would think it was all part of the casting.





Online Jasonb

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Re: Reinventing the Real.
« Reply #14 on: May 26, 2022, 07:18:18 PM »
As I had cut off a bit of 12mm PGMS to use as a plug gauge for the flywheel hole I thought I may as well work on the crankshaft next.

Starting with a piece of the 20mm square bar I had bought for the column bases it was machined down to an oversize rectangular section and then thinned further at the pin end followed by reaming the holes for the shaft and pin.



I could then use the hole to gauge the fit of the reduced diameter at the end of the crankshaft



The crank can then be shaped in a number of ways from simple buttons and filing, to using the rotary table or the CNC if you have one. I opted for the last and used a 4mm dia cutter with a 1mm convex corner radius so it left a nice fillet on the internal corners.



With that machining done the crank was Loctited (648) onto the shaft and set aside to cure. Hold the shaft to run as true as you can in a collet, 4-jaw or good 3-jaw and then skim the crank to finished thickness. This ensures the face that the crank pin will be tightened against is at right angles to the crankshaft's axis and therefore the pin should end up parallel to that when fitted.



I'll come back to the pin later once the conrod bush is turned and fitted so it can be used to gauge the fit.

While I had a bit of time to spare a small part was ticked off the list in the form of the valve rod clevis. I often mill my on small square, hex and rectangular components from round stock a sit's often not worth buying a 300mm length of a size you won't use much plus some small square stock is not that crisp and often comes with rounded corners. After milling the Slot was formed with a 1.5mm slitting saw then the part was cut off the parent bar. I used a square collet but the 4-jaw will do to hold while the end was turned, drilled and tapped, I'm using a 2mm radius tool which like the milling cutter mentioned above leaves a pleasing small internal fillet.








Online Jasonb

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Re: Reinventing the Real.
« Reply #15 on: May 28, 2022, 05:01:35 PM »
With the arrival of some additional material the build can now follow a more logical direction starting with the base.

As I said in the introduction the one supplied by Stuarts is little more than a rectangle with rounded corners and a bit of draft angle which only needs flattening on the bottom, skim cut off the top and a few holes added which does not give you much workshop time for your money as it should not take more than an hour to do.

I opted for aluminium as it's easy to cut and no more expensive than bright steel flat. I've not noticed any problems with my other models that use aluminium right from the early ones I made 30+ years ago like the Minnie which has several aluminium castings through to others with aluminium castings and the ones I have fabricated using the material. Even Stuarts have used it to cast the fluted column of the Williamson.

So starting with a piece of 12mm material it was sawn slightly oversize and clamped to the mill table on some packing so that three sides could be milled square to each other. I then drilled four hole 5mm which were later countersunk on the underside for M5 CSK socket screws. These holes were also counterbored from above by plunging with an 8mm 3-flute cutter to form sockets that spigots on the column bases will fit tightly into so they locate accurately. I also drilled and tapped M4 for the studs that will hold the cylinder cover in place and at the same time added a small hole to use as a datum at the ctr of the cylinder position that could be used to locate the base on the rotary table if using that to mill the half round.



The two areas of waste were hacksawn off and put aside as they can be used for other parts later on then the front face with it's half round was milled to size and the decorative moulding added firstly by cutting a rebate 10mm deep and then using a 12mm ball nose cutter to do the concave detail.



The straight sides were next, to make it easier I clamped a straight edge to the mill table and clocked it in so it was then an easy job to locate each side against this and machine at the same settings. First doing the rebate and removing some of the waste with the same straight 10mm cutter.



Then the concave with the 12mm ball ended one



You can always judge if you have had a productive session in the workshop by the size of the pile of swarf produced.



The completed base which to my eye has a much more interesting overall shape and the moulded edge looks a lot nicer than the rather plain original. Plus with materials at 1/4 the cost of the casting and a bit more time needed to machine you are getting better hours enjoyment per £  :)




Offline Michael S.

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Re: Reinventing the Real.
« Reply #16 on: May 28, 2022, 06:17:45 PM »
Hello,

I think this is an excellent foundation to start a beautiful steam engine! I really like the base plate. Keep it up!

Michael

Online Jasonb

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Re: Reinventing the Real.
« Reply #17 on: May 30, 2022, 07:07:04 PM »
The only other casting that I decided to use was one for the cylinder, again this was a very good casting and only needed a light fettle with files before I could start machining and not forgetting to clean out any remaining core sand from the cast in steam passages.

Part way through doing the cylinder I realised that there was a way to machine the portface, bore and one end of the cylinder all in one setting which would ensure all are true to each other so would suggest that the cylinder is mounted in your vice with the port face up and the piston rod end of the cylinder just protruding from the side of the vice jaws not in the middle as the first few of my photos show.

I started by setting up the casting so it was as true as possible in the vice using some thin strips of aluminium between the jaws and casting to take up any irregularities and give a good grip. Not knowing if there may have been some hard spots I took a clean up cut with an insert face cutter.



All was well and I also used this cutter to clean up the two flat areas above and below the portface, the 0.8mm radius corner of the inserts leaving a nice internal fillet. Changing to sharp 6mm cutter the portface was machined to finished size, using a small cutter with a 60-70% stepover gives a good flat surface that you may not get with a larger dia cutter if the tram is a bit off.



There was also just room to get the 6mm cutter down the side of the portface to remove the protruding exhaust connection boss as I won't be needing that.



I then drilled and tapped for the valve chest studs. rather than the original six hole pattern I went with an eight hole one as that cleared the side inlet position I wanted to use rather than connecting the pipe to the steam chest cover which is a bit of a pain when it comes to setting the valve position.



Over to the lathe and with the casting in the vice now shown in the position it would be best to start out with  it was just a case of adding some packing under the vice to bring the cylinder ctr line up to that of the lathe and using a between centres boring bar to take the cored hole out to the required 25mm bore.





Without disturbing the cylinder in the vice the end of the cylinder that will have the piston rod can now be machined square to the bore by using a flycutter



Back to the mill with the recently flycut end clamped to the mill table the other end can be milled and the cylinder brought to the desired length.



Finally for now with the portface registered against the vice fixed jaw the cylinder ctr can be found and the holes drilled and tapped. I used six M3 holes at the bottom to take M3 CSK socket screws up through the end cover and eight M2.5 at the top for studs and nuts as they show.



I'll cover that exhaust alterations lather in another post.




Offline Admiral_dk

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Re: Reinventing the Real.
« Reply #18 on: May 30, 2022, 09:25:08 PM »
I like the way you keep several faces and axes aligned this way  :praise2:

Keep it coming Jason - I (and others) will be following  :cheers:  :popcorn:

Per

Online Jasonb

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Re: Reinventing the Real.
« Reply #19 on: June 01, 2022, 08:23:39 PM »
Thanks for the comments

The entablature supplied with the engine is really the" wrong way up" as classic architecture would have the bottom smaller than the top so it flairs out much like the capitals at the top of a column. So a new one was designed to be the right way up and also have a recessed middle band and raised bosses for the bearing supports and column nuts.

I started by milling down some 5/8" flat bar to 15mm thick with an 80mm insert facemill and then used a 6mm split point stub drill to stitch drill out the waste, These drills don't really need spotting first and being short don't wander into the previous hole. Keep the bit of metal removed from the middle as it will get used later.



After milling out the rectangle the four sides where milled to profile, for th emid section I used a 6mm cutter with a 1mm conver corner radius which leaves an internal fillet for that cast look.



After that the various holes were drilled and the bosses machined with the same corner radius cutter, I used the CNC but if you were doing similar on a manual machine then I would mill the two rectangular bosses but counterbore for the round ones and loctite in four turned "washers" unless you want to set up for each one on a rotary table. You can also see on the far side of the cut out that there is a deeper section which gives additional clearance to the eccentric allowing it to sit closer to the valve chest helping to do away with the cranked valve rod of the original design.



The bearing supports start out as rectangles of aluminium from the same piece that the base was cut from, Milled at each side to leave the feet and then drilled and tapped for the bearing caps



A two flute carbide cutter specifically for aluminium makes quick work of this taking full depth passes of 1.5mm wide per pass.



A simple vice stop allows the two parts to be swapped over in the vice without the need to keep locating their position and a spiral flute tap removes the swarf from the blind taped holes



To make it easier to hold the bearing caps while they were machined I cut them on each end of a larger piece of material before cutting them off and cleaning up the cut with a quick skim of a facemill.



Before cutting off I spot faced for the fixings and also milled a shallow counterbore which will have a short length of rod loctited in that has been threaded M4x 0.5 metric fine for an oil cup.



I tend to use cap head screws during construction as they are quick and easy to screw in and undo multiple time s with a suitable ball ended driver. Here you can see them being used to hold the cap to the support while the bearing hole is bored. I have packing on each screw head so that the pressure is not on the crown of the cap which may distort it.




Online Jasonb

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Re: Reinventing the Real.
« Reply #20 on: June 02, 2022, 06:53:40 PM »
The columns on the engine are quite a noticeable feature, the book just shows them parallel turned to 1/2" diameter from 5/8" stock leaving a small flange at each end and a not "embellish as desired" which I decided to take them up on

I started out with some 14mm rod, this was ordered as EN1A but was really nasty to machine and also had quite a pronounced spiral finish on the outside. If you look closely at the threads on the right they were tearing and I was not hopeful of getting a good finish on the long slender taper.



After reducing the top 10mm length to 11mm diameter I then changed setup gripping this short length in the 5C chuck and supporting the other end with a small rotating ctr held in my Boring head which was offset to allow the taper to be cut. Initial cuts were not good but after trying a few different inserts I settled on a CCGT insert with 0.8mm tip radius which seemed to give a reasonable finish.



Then driving by holding the top spigot I just hand filed the rectangular ring that I had left into a half round profile and also gave the columns a quick going over with Emery cloth to clean up the finish good enough for painting.



I cut off 4 pieces of 20mm square steel, faced one end and tapped it to suit the turned part of the column then the other end had a spigot turned to closely fit the counterbores in the base before drilling and tapping M5. After this I milled 1mm off each side leaving 3mm at the bottom and 2mm at the top the full 20mm size. This was done with an insert endmill with 0.8mm corner radius tips  which once again left an internal fillet for that cast look.



The piece of aluminium that I stitch drilled out of the entablature was milled down to 15mm square and the capitals machined from that using a form tool before parting one of and then repeating for all four.






Most columns of this style also have a half round section between the square base and tapered column so some thick "washers" were parted off and then screwed onto a mandrel for profiling.



It was now just a case of assembling the various parts with soem Araldite expoy adhesive and setting aside for 24hrs to cure. After the top spigot was held in teh 3-jaw with the capitol hard up against the jaws which acted as a stop. It was then just a case of locking teh carriage and facing each end to final size which ensured all would be the same length.



Close up of the bottom



And progress so far at which point I started to think that it could possible take a larger diameter flywheel :thinking:







Offline Bearcar1

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Re: Reinventing the Real.
« Reply #21 on: June 02, 2022, 07:40:03 PM »
 :popcorn: :wine1:  I've been quietly following along on your journey Jason, and I have thoroughly enjoyed the ride!  Larger flywheel? Well, maybe. The embellishments you have done so far make this an interesting piece of machinery.


BC1
Jim

Online Jasonb

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Re: Reinventing the Real.
« Reply #22 on: June 04, 2022, 04:54:18 PM »
Don't worry Jim, the flywheel grew on me and as you will see if you continue to follow along it looks OK on the finished engine.

Stuarts use a square cylinder end cover to mount it to the base but as mine has the rounded projection that really needs a round cover to match. So a slice was sawn of some 60mm CI bar, faced and the OD turned. I then flipped it round in the soft jaws to face down to finished thickness and turn the locating spigot for the cylinder



Once again I used the mating part to gauge the fit of the spigot into the cylinder



The only remaining turning was to bore a shallow recess to give some clearance for the piston lock nut.



Then over to the mill, the clamps are set at approx 45deg so I can use an edge finder to locate X and Y then the drilling can commence, The six 2.5mm holes were later csk on the underside for socket head CSK screws. The five 4mm holes are for studs to hold the cover to the base. They are not equally spaced, the ones at 4 and 8 o'clock are a little more forward as I was toying with the idea of adding drain cock bosses to the side of the cylinder but decided not to in the end as I don't really need them with air but the thought is there if anyone wants to try these modifications and run on steam. I went with 4mm as the Stuart specified 2BA (4.7mm)looks a bit bulky particularly with their full size hex heads, my nuts will be 5.5mm A/F



Two slices from the same 60mm cast iron bar can be cut and machined to the overall sizes of the valve chest and it's cover. Then a spigot turned on the end of the valve chest with a round nosed tool before drilling and reaming for the valve rod. I'm not keen on having to drill a guide hole for the rod at the opposite end of the valve chest so once again deviated from the Stuart design and I will use a separate external guide similar to that found on their No1. I opted for round glands to keep the round theme going but oval ones are not too hard to do on the rotary table of you prefer.



The middle was then stitch drilled out before cleaning up with a 3mm milling cutter then the revised eight hole pattern for the studs drilled, this pattern will allow me to bring the steam/air in through the side of the chest without clashing with a central stud and does away with Stuarts method of attaching the steam supply to the valve chest cover which can be a pain when you want to adjust the valve as you have to strip out the pipework each time.



The chest cover was drilled straight after and then a decorative recess milled with a 4mm dia x 1mm corner radius cutter





« Last Edit: June 04, 2022, 04:57:30 PM by Jasonb »

Online Jasonb

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Re: Reinventing the Real.
« Reply #23 on: June 09, 2022, 08:16:49 PM »
As i doubt my engine will ever do enough hours to need the bearings adjusting I did not bother to make them split, instead I just turned them from bar. The inside was bored to get the fit I wanted on the crankshaft and the waist in the middle to fit the bearing supports before being parted off.



The M5 acorn nuts were made from round bar milled to one size smaller hex (7mm) and then the ball turner was used to shape them, the triangular insert has the advantage of leaving a nice chamfer on the top of the hex. After parting off they were held in a hex collet though a 3-jaw would do and drilled and tapped M5. While the ball turner was set up I also made two M3 versions to go on the top of the crosshead guide rods





Here are the bearings and nuts in place



You may also notice in the above photo a slice of ERW tube which is the basis for the more attractive pulley rather than the standard cast Stuart item that they use on all the 2 x 1 engines. The spokes were cut from a piece of 2.5mm steel sheet which was quite easy on the CNC but all the curves are parts of circles so could be done on a rotary table.





After a bit of "softening" with the dremel and turning two bits of steel that will form the hub all were ready for soldering.





held in the 3-jaw the outer face was cleaned up followed by the edge of the rim & hub and finally the undersize hole in the hub was bored out to fit the crankshaft



I then swapped to external jaws so that the other side could be finished



That's another part that can be crossed off the list.




Online crueby

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Re: Reinventing the Real.
« Reply #24 on: June 09, 2022, 08:21:52 PM »
Love the acorn nuts and the curved spokes on the wheel!  Which ball turner setup do you have?

Online Jasonb

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Re: Reinventing the Real.
« Reply #25 on: June 09, 2022, 08:39:47 PM »
Thanks, I made a Bedair type one some time ago.


Online crueby

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Re: Reinventing the Real.
« Reply #26 on: June 09, 2022, 08:45:52 PM »
 :headscratch: How does that turn the outside of the acorn nut ends....

Offline Admiral_dk

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Re: Reinventing the Real.
« Reply #27 on: June 09, 2022, 10:04:04 PM »
Quote
:headscratch: How does that turn the outside of the acorn nut ends....

Move the Cutter to the Outside instead of the Inside off the Centre off the Tool - see the "Moving Sledge" in the middle ....

I really like your additional details Jason  :ThumbsUp:

Per

Online Jasonb

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Re: Reinventing the Real.
« Reply #28 on: June 10, 2022, 06:59:50 AM »
In the photo of the ball turner I have it set for concave cutting eg the insert is beyond the axis of rotation. For balls and convex surfaces I slide it back behind the axis and the cutter follows an arc. If that's not clear say so and I'll video it in action.

The final shape be it a ball or acorn is just a case of positioning the axis and the radius of the cut

Online crueby

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Re: Reinventing the Real.
« Reply #29 on: June 10, 2022, 01:13:24 PM »
Got it, at first I didn't realize that the block was lower than the lathe acis and the cutter projects up.


 :ThumbsUp:

Offline steam guy willy

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Re: Reinventing the Real.
« Reply #30 on: June 10, 2022, 02:39:28 PM »
Hi Jason , this is looking really lovely and lots of really nice photos to explain everything,....inspiring work

Willy

Offline Zephyrin

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Re: Reinventing the Real.
« Reply #31 on: June 12, 2022, 09:36:39 AM »
this will gave a impressive and elegant engine, with ornamental turning, as old designs require...
another great thread to follow.
and yes, sharp an clear pictures to show the machining !

Online Jasonb

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Re: Reinventing the Real.
« Reply #32 on: June 12, 2022, 05:14:29 PM »
Thanks Chaps

A slice of CI was held in the soft jaws and turned to the diameter of the cylinder top cover, then faced and the spigot cut. I then spotted, drilled 4.8mm with a stub drill and finally took the hole out to the required 5mm diameter with a machine reamer.



Now holding the other way round the boss for the gland was turned leaving a flat area for the nuts, I used a brazed carbide tool with a rounded nose to get the larger fillet at the base of the boss.



With the cover screwed to an arbor which in turn was held in an ER32 block the outer edge was kept clear so the edge finder could be used to locate the cover's ctr then set about drilling some holes. 8 @ 2.5mm for the studs, 2 @ 3mm which were CSK on the underside for the cross head guide rods and 3 @ tapped M1.6 for the gland studs



The gland was quite straight forward turning to fit the cover and reaming for the piston rod.



Then held the other way round to face off, add a decorative spigot and CSK the hole to encourage any oil back into the cylinder rather than running over the engine.



Another small part tackled at this stage was the valve, just a piece of bronze milled to the overall size and then the recess milled into one face with a 2mm dia cutter



The opposite face had slots cut to clear the valve rod and at 90degrees to that one to take the valve nut which was just a offcut of brass left from the eccentric strap.


Online Jasonb

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Re: Reinventing the Real.
« Reply #33 on: June 15, 2022, 07:18:26 PM »
Returning to the cylinder and it's time to reposition the exhaust connection from the of the valve port face to the opposite side of the cylinder which is a bit less cluttered by columns and the now repositioned inlet. A piece of steel was turned to the same diameter as the cylinder end flanges then bored to the average diameter of the cylinder body. I then used an internal grooving tool to hollow it out to a sort of rectangular "U" section.



A 14mm diameter was turned onto the end of a bar and the Soba boring head used to cut a radius to match the outside diameter of the cylinder.



Then holding it in a collet block two grooves were cut that would allow the air/steam to flow from the new passages around the cylinder into a  drille dhole in the boss and then out to the plumbing.



After sawing a couple of pieces off one end was cope cut to suit the 14mm dia exhaust boss and then the other ends fitted by filing until they sat nicely against the back side of the portface.



Two holes were then drilled on either side down to meet the central port. I used CAD to work out the angle of the holes and set the cylinder using an angle gauge.





Finally a bit of needle file work had the two holes formed into a slot - too deep to get all the way with a milling cutter. At the design stage I had made sure that these slots, the new ducts and the slots in the boss were all greater in area than the smallest port the air/steam would have to pass through so as not to restrict flow.



It was then time to boost Ramons shares in JBWeld and stick the new bits to the cylinder casting. I have a few plastic spatulas that I have cut different corner radii on plus some rods with rounded ends and use these to get a basic fillet which saves time filing and sanding hard JBW





Once set but before tidying up the JB Weld I milled the boss back to the required length and drilled and tapped for four M1.6 studs to retain the flanged pipework.

« Last Edit: June 15, 2022, 07:23:35 PM by Jasonb »

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Re: Reinventing the Real.
« Reply #34 on: June 17, 2022, 05:00:02 PM »
As I mentioned when dealing with the valve chest I'm mot keen on Stuarts way of guiding the valve rod end in a hole that is a long way from where you can hold a drill bit so another option was needed. I decided upon a similar guide to that seen on the No1 which is a bracket that makes use of two of the cylinder studs to hold it in place.

I started by thinning down a short length of Tee section brass though two separate bits could be used. Then hauled up the boat anchor that is otherwise known as my long serving Indian made Soba rotary table and bolted a vice to that. Then another smaller vice to hold the tee section so a semi-circular notch could be cut on the overhanging end, two mounting holes drilled and then the rotary table used to cut the two arcs.





After a bit of rough shaping I  silver soldered a length of bronze rod to the end. To ensure that the valve rod ran nice and true through the guide I first set up the cylinder complete with valve chest on the mill and located the valve rod hole with a short length of silver steel (drill rod) held in a collet and locked the slides. You can also see the beginnings of the inlet elbow in this photo, just needs the D section rounding and a flange soldering on.



I then swung the bracket round into position and screwed it on tight. With some packing under the end so it did not sag it could then be drilled out to take the rod.



A bit of final shaping and rounding over the ends of the curved bottom were all that remained to do.

The eccentric strap started life as two pieces of brass that were soft soldered together before milling to the desired thickness and adding a ctr hole.



This hole was used to get the strap running true in the 4-jaw so it could be bored out and then a grooving cutter used to form the groove that the ridge on the eccentric will run in



A quick and dirty top hat bush was made to hold the strap while the outside profile was milled another job for the Rotary table of CNC if you have one. I also cut a recess for the valve rod which helps get a straighter run for the rod thus avoiding the dog leg of the Stuart design



The last job before unsoldering was to drill and tap the two lugs and ctr drill the top to form a small oil pocket.








Online Jasonb

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Re: Reinventing the Real.
« Reply #35 on: June 19, 2022, 06:31:42 PM »
Now that the strap was complete it could be used to gauge the size of the eccentric. After facing and turning to the required OD a small parting tool was used to create the central ridge which stops the strap moving sideways first by plunging and then by moving sideways with shallow cuts.



The size was adjusted until the strap would fit but not bind when tightened together.



I then used the height gauge to scribe the offset centre before punching the intersection and then setting the punch mark to run true in the 4 jaw so the hole for the crankshaft could be bored.



After drilling for a grub screw the eccentric could be mounted onto a stub of bar so that the boss could be turned down to finished size.


A piece of bronze was machined square and then the two holes for the guide rods reamed, piston rod hole drilled and tapped and at right angles a hole for the cross head pin was reamed.



The guide rods are just pieces of 5mm silver steel drilled and tapped M3 at each end afire carefully turning to the same length. They are held yo the cylinder cover by CSK screws from below and studs and nuts through the brace at the top. A quick test before shaping the crosshead and all seemed well with it moving smoothly up and down the guides.



The top bracket was cut from some 5mm flat bar to a shape that pleased my eye, a lot easier than bending up one as per The Stuart design. Here it is having the last two holes drilled for the studs that will hold it to the columns.



To ensure that the top brace was in the correct position slots had to be cut into the tapered part of the columns. To do this I first clamped a straight length of bar to the mill table and clocked it true. Then packed the smaller top end of the column both up and away from the straight edge so that it's axis was true along the mill table. It was then just a case of milling a 5mm slot and drilling and tapping for an M3 stud.



The cross head can be shaped however you like and will in some ways be limited by the available tooling if not your imagination, this is what I went with which was done with a mix of manual and CNC mills. Both this and the eccentric will be bead blasted to give them a nice satin look.




Online Kim

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Re: Reinventing the Real.
« Reply #36 on: June 19, 2022, 11:27:20 PM »
That is a very pleasing shape for your crosshead, Jason!

Kim

Online Jasonb

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Re: Reinventing the Real.
« Reply #37 on: June 22, 2022, 05:03:47 PM »
Thanks Kim

The last major component is the conrod. as I have changed the crosshead design there will be no need to make the "tuning fork" shaped one of the original which had to be shaped that way to clear the extended piston rod. There are a few options for conrod designs but I decided to keep to something fairly simple and came up with a rod that is not too far removed from that found on other Stuart engines like the Beam and Victoria.

Starting with an over long length of 16 x 16 black (hot rolled) bar which was pickled for a while in brick cleaning acid to remove any scale I set it up in the mill vice and brought it down to the maximum size rectangular section needed to get the part out of. I flipped it over a couple of times to take equal amounts of opposite sides and that combined with the black bar meant it remained straight.



After reducing the areas around the big end (right of image) and the small end (left of image) to their overall rectangular size I spotted, drilled and then reamed the two holes. I have left some excess to the left which will allow me to hold it for turning, this gives a more solid setup than turning between ctrs and means the interrupted initial cuts don't seem to knock as much plus you can take heavier cuts to get it down to round. You may be able to make out an angle plate  (mounted at an angle) on the right, this was used as a stop to maintain position in Y as the part was turned in the vice.



With the rod rotated 90deg in the vice I then milled a slot which will form the forked end once the chucking material has been removed. I've clamped the end to another angle plate jost to make sure the overhanging end is as rigid as possible so there is less chance of any cutter chatter.



With the job now held in the 4-jaw chuck and supported at the other end with a revolving ctr it was turned to the largest diameter of the "fishbelly" and then a Sharpie used to mark approx 1/3rd in from each end. You can also see that I have left the rectangle section at the crank pin end a bit longer than the Stuart ones so that I can put in two dummy strap bolts rather than one.



The topslide was then set over a few degrees and one end tapered followed by setting it the opposite way and tapering the other 1/3. I use an insert with a 2mm dia end so that a nice fillet was left in the transition from round to rectangular. All that remained was to blend the three facets with files and then emery to get a smooth looking fishbelly to the rod.



Having the extra SX2.7 mill in the workshop I tend to leave the ARC rotary table and chuck on that so it's a quick setup to mount anything that needs rounding over on one of the many arbours that I have built up over the years and round the ends on the mill. here I have a sacrificial washer between arbour and work so the cutter can have it's end just below the work and the M8 nut at the top is unlikely to be much use for anything now but I've got a big pile of them. Rounding was done with full depth cuts, 1mm stepover for the first few and then reduced to 0.5mm once the nut started to get cut too.



The forked end was rounded in a similar way after sawing off the chucking piece and then just a bit of file work to blend the outside of the fork into the round rod and get the fork to look "U" shaped.



« Last Edit: June 22, 2022, 05:10:17 PM by Jasonb »

Online Roger B

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Re: Reinventing the Real.
« Reply #38 on: June 23, 2022, 08:49:24 PM »
Looking good and very instructive  :ThumbsUp:  :ThumbsUp:
Best regards

Roger

Online Jasonb

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Re: Reinventing the Real.
« Reply #39 on: June 24, 2022, 08:13:36 PM »
having just seen the latest collaberation with Graham C come to life I best get on and finish this one to make room for another project, the dancing can be seen on FB :pinkelephant: Not sure if the link will work https://www.facebook.com/100013321802733/videos/742278877114088/

I'm a bit of a fan of aluminium pistons in engines both IC and steam as they do reduce the reciprocating weight so starting with some 1" 6082 bar the end was faced, spot drilled, drilled tapping size right through and then counter drilled 5mm (piston rod size) for about 1/3rd the piston thickness before being tapped M5 with a spiral flute tap.



After sawing off a length the sawn surface was faced and a counterbore turned so that a lock nut can be used on the piston rod but not hit the cylinder end cover.



The piston was then screwed onto the previously prepared stainless steel piston rod and locked with a thinned down nut never to be taken apart again. Then holding by the rod in a collet and with tailstock support the OD was taken down to 25mm using the cylinder to once again gauge the fit followed by cutting a groove for an O ring



Well that covers all the parts I took specific photos of but there are a few others which luckily seem to have all migrated to this corner of the group photo.



The Eccentric rod is just 1.5 x 5mm section reduced down from the next available stock size, drilled at both ends (one CSK) and then rounded over.

A couple of pins for the crosshead, valve rod/eccentric rod, etc are just basic turning. A couple of flanged pipe fittings, I decided just to do short stubs and not fully plumb in the engine.

There is also the cylinder cladding which was some veneer that I cut up into planks with a scaple and stuck onto some thin linen which makes them easy to handle as one so they can be cut to a card template. The brass bands hold the cladding in place.
« Last Edit: June 24, 2022, 08:46:36 PM by Jasonb »

Online Jasonb

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Re: Reinventing the Real.
« Reply #40 on: June 24, 2022, 08:31:48 PM »
The keen eyed will have spotted that I went with an off white paint colour for this engine, Ford "Ivory" was what caught my eye in Halfords. Non ferrous metal was primed with Upol Acid8, the Flywheel and cylinder with Upol High5. Bothe were then given a coat of Halfords white primer as were the remaining steel parts to get a uniform base for the topcoat.

A few shots of the parts laid out prior to final assembly, the engine having been test run before hand as I like to sort out any issues if there are any without the risk of damaging the paint if you have to start pulling things apart a few times. All visible fixings are small hex metric, mostly studs and nuts which you can see in one container and those that don't show are socket head.









Well lets see what they look like all put together.















So that about wraps up the build. I'm happy with how it turned out and it has fulfilled my initial desire to show that an attractive and individual model can be built based on an existing design for about half what it would cost if you bought the full kit and you also get a lot more workshop time for your outlay.

<a href="https://www.youtube.com/watch?v=KIDrN83xxq0" target="_blank">http://www.youtube.com/watch?v=KIDrN83xxq0</a>

I don't know how many of you are like me and enjoy looking at "naked" models (not that sort). Be it plastic AFVs, miniature figures or model engines I like to see them before they are painted a sit lets you see some of what has gone on in the construction as well as materials and methods used so here is a video of the early test run, just tacked together with a few screws, minor bits missing, no gaskets, packing or piston rings. It was also before I added the balance weight to the flywheel.

<a href="https://www.youtube.com/watch?v=7doDFAH32F4" target="_blank">http://www.youtube.com/watch?v=7doDFAH32F4</a>

Online crueby

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Re: Reinventing the Real.
« Reply #41 on: June 24, 2022, 09:14:44 PM »
Beautiful!!

Offline bruedney

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Re: Reinventing the Real.
« Reply #42 on: June 24, 2022, 10:32:49 PM »
Amazing yet again Jason.

Where do you keep all your models as you must have quite the collection by now?

What's next?

Bruce
‘Results! Why man, I have gotten a lot of results. I know several thousand things that won’t work.’ — Thomas Alva Edison

Online Kim

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Re: Reinventing the Real.
« Reply #43 on: June 24, 2022, 11:10:28 PM »
That's a very elegant-looking engine, Jason!  :ThumbsUp:

Kim

Offline Bearcar1

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Re: Reinventing the Real.
« Reply #44 on: June 25, 2022, 06:46:44 AM »
Smooth as a baby's bottom!! Choose the colors carefully and the entire presentaion will just POP!! Well done Jason..... I love that cross slide treatment..... just WOW!!!


BC1
JIM










Offline Michael S.

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Re: Reinventing the Real.
« Reply #45 on: June 25, 2022, 01:00:40 PM »
You did a great job on the steam engine. 👍 It looks very elegant and runs great.

greetings Michael

Online Jasonb

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Re: Reinventing the Real.
« Reply #46 on: June 25, 2022, 04:51:30 PM »
Thanks all.

As to where I keep them that is becoming more of a problem, small ones in a display cabinet, medium dotted about on shelves and the larger ones taking up a few window cills but space is running out. At least the vertical designs don't have such a large footprint.

I'm having thoughts about giving the James Coombes a similar treatment. Would get rid of the box bed and outrigger. More decorative base and entablature in plate of the plain steel plates, maybe a larger flywheel and some more interesting columns for starters.

Offline Admiral_dk

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Re: Reinventing the Real.
« Reply #47 on: June 25, 2022, 07:47:25 PM »
A skightly belated congratulations (windows crashed vile trying to see the Video on YouTube yesterday  :killcomputer: - had to re-Install today).

Another great runner from you Jason  :praise2: - I can also see why you choose to add the balncing bit on the Flywheel  :ThumbsUp:

Per

Offline Dave Otto

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Re: Reinventing the Real.
« Reply #48 on: June 25, 2022, 07:50:52 PM »
Beautiful engine Jason, I do like the color.

Dave

 

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