Author Topic: Building Fred  (Read 14977 times)

Offline arnoldb

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Building Fred
« on: August 14, 2012, 10:21:13 PM »
This is another re-post; this time of my very first live steam project (and third fourth) running engine build) of a 32mm (O Gauge) "coffee-cup" steam locomotive.
It's based on the "Idris" plans that Mr Dave Watkins kindly made available for free; If you'd like to read more about the background of this locomotive or download the plans and Mr Watkins' build description, you can follow this link to his home page.

It was the most labor intensive engine I've built to the present date, but even now, two and a half years on, this particular build is by far the most fun one.  It was built only on the lathe and drill press, and if ever there was one of my builds where I could attribute real skill-building (well, such that I may have anyway) to, it's this one.  I got to try out many new techniques - such as making rivets, plate work, building a properly tested boiler and so on. 

By far the best lesson I learned from this build was that the humble file is one of the most useful tools in the shop.  In fact, since this build, my collection of different shapes and sizes of files have grown exponentially; and it is extremely rare for any part I make now, no matter how small or large, not to be touched multiple times by a file during the build and finishing process.  To all my mentors that demonstrated and commented on filing techniques - THANK YOU!  :NotWorthy:

I'll be doing some, but minimal editing to the original build log while posting; it takes quite a bit of time to do that...

07 November 2009
It's taken quite a lot of searching to get together suitable materials for the build to start, but I think I have enough together now.
 
 My loco will be called Fred - after my grandfather, who provided me with a nice piece of copper plate and other odds & ends.
 
 First up, I'll do the loco frame. Please excuse the quality of the photographs; there is something wrong with my camera....
 
 Thursday evening after work I managed to get into the shop for an hour and a half. I started with a piece of 1.6mm plate I got off an old UPS cover:
 
 
 I marked and bandsawed 2 x 24mm wide strips off it - this is oversize so that I can file the sides straight and to the required 22mm width:
 
 
 Then I clamped the plates and a guide plate together, mounted the whole assembly in the big vise and settled down to an extended period of filing:
 
 
 One of the things I have not been able to find is suitable 6mm angle for the frame supports and corner pieces, so some improvisation is needed. At noon today on I started in the shop by sawing some square tubing I got out of an old printer in half to get angles. I did this on the bandsaw, using the table blade groove as a guide. It's blade does not run in the exact center of the groove, but I used this to my advantage to get one "good" piece of angle iron from the cut; the other side warped away:
 
 Some more sweat and filing was then applied to the angle to trim it up.
 
 Part of the reason for my late start today was that I needed to go and get paint stripper from town to get the old paint off the plates. What a waste of time. I don't know what kind of paint was on these plates, but the paint stripper did absolutely nothing to it. So I took the lot outside, and used a blow torch to burn off the paint. Then an extended session with a wire wheel in the drill press to get rid of all the last bits still sticking. A bit of a safety note: On many drill presses (like mine) that use a morse taper shank and jacobs taper on the chuck, one of the two tapers is liable to come loose when trying to use loose running toolbits like a wire wheel. To make sure the jacobs part on my setup does not come loose, I fit the chuck to the shank by heating the chuck in the oven and freezing the shank in the deep freeze, then tapping them together. This pretty much a permanent solution; one is very unlikely to get them apart again. To make sure the morse taper does not come apart, I made a ring with 2 rows of grub screws that secures the shank to the spindle after it is inserted. If anybody wants a picture of this, just shout  :)
 
 After the plates were clean, I superglued them together, and swiped permanent marker ink over the one face to do the layout:
 
 
 Some quality time with the measuring instruments followed, and then a lot of hole-drilling. Part way through chain drilling for the cut-outs, the heat generated started to melt the superglue and the one end of the plates wanted to come apart, so I had to clamp the plates on that side. I let things cool down and drilled the last couple if holes. More filing still required:
 
 
 Next up was a lot more filing. It was 34 degrees here today, so it was hot job to do the filing, and once done, I called it a day. End of day's work - not much for all the time spent! - Frame sides done, and some 6mm angle:
 



08 November 2009
Didn't get too much done today; just drilling and riveting - and sorted out the camera.
 
 First up, cut the angle to the needed lengths, and clamped to the "inside" surface of the side plates to drill for the rivets. I marked both side plates on the inside with a couple of punch marks so that I would not get them mixed up and end up riveting the angle to the wrong side. All drilled through:
 
 
 I have never in my life done riveting, except for pop-rivets. Searching around locally, I could not find suitable ones for the project, so some improvisation was needed.
 After some testing, I came up with a method that seems to work OK. A piece of 1.5mm copper wire, a pin with a hole drilled in for a short length, and a pin with one end turned down to get in the tight areas, and the point dimpled with a drill to help form rivet heads (sorry for out of focus):
 
 
 First off, I insert the wire through the plates and into the hole in the pin clamped level with the top of the vise:
 
 
 Then clip the wire off a short length above the plate:
 
 
 Hammer it down with the dimpled pin:
 
 
 The half-formed rivet already stays in place and holds the plates together, but pulls easily out of the bottom pin, so I just did all the rivets on one side (the inside where the "mess" I made will not be as visible  :paranoia: :
 
 
 Then turned the whole assembly around - here you can see the other sides of the rivets showing:
 
 
 I then clipped all the rivets evenly to about 1mm length with a side-cutter and used the dimpled pin to form the rivet heads. By having the excess to an even length, a fairly uniform row of rivet heads were formed on the "presentation" side. End of work today showing one side plate's "inside", the other the presentation side:
 
 
 The plans calls for "curved" angle and side plates, but I'm not making that. My boiler will be a couple of mm less in diameter than the plans calls for, and will have adequate clearance. Dave Watkins mentions this possibility in his "build log" - with the caveat that an alternate means of securing the boiler will have to be found.


14 November 2009

After a month's wait, I finally received the railroad track I ordered, but the people at trainz.com sent me the wrong tracks... When I placed a complaint, their inventory manager responded that I need not send the wrong track back because of the international shipping costs, and that the correct track would be dispatched immediately. If they come through on this, I would qualify it as GREAT service; If not, I'm out of pocket a lot of money - I'll see which in 4-5 weeks...
 
 My old faithful camera has finally given up the ghost after many thousands of photos, so this morning I splurged on a new one. I'm still learning it's ins & outs, so the photos below might not be quite up to standard... (though mine has never really been  ;) )
 
 On to work.
 Yesterday evening, I finished the front and rear frame plates. Just more sawing & filing & paint removal & hole drilling, so not a lot missed without having a camera.
 
 I made one build "error" so far; I didn't drill & thread the angle pieces that would make the front & rear frame plates bolt to the side plates before riveting the angles to the side plates... Drilling & tapping the holes were now pretty difficult. To do this, I used some threaded rod through the holes for the wheel bearings to set the side frames to the correct width apart. A strongish magnet helped to keep the end plates in place so that I could clamp them up:
 
 
 As I had to manage the entire frame, and had to drill on the ends, I decided that it might be easier to just clamp the whole assembly in the bench vice, and drill the 1.6mm holes with the Dremel. BIG mistake. My 20 year old Dremel does not have speed control and runs at 15000 rpm (I think), and on the second hole, I didn't dive in positively enough, and this happened to the 1.6mm drill bit because of friction:
 
 This also work-hardened the hole in question a LOT!
 
 After that, I "fudged up" a way to hold the assembly in the drill press. I couldn't properly clamp it, so held it by hand with the toolmaker's clamps resting and providing some support in the ring normally used to secure the drill table. Forgot to take a photo of that setup; if anyone's interested I can take a "staged" one at some point. Fortunately, I had a couple more 1.6mm drill bits to finish the job. The work-hardened hole blunted another one...
 
 Tapping the holes was fun. All went well, except for the work-hardened hole... I broke a tap for the first time in my life; so destiny has finally caught up with me; it was bound to happen at some point:
 
 Fortunately the hole was nearly done and the broken bit came out easily with the automatic center punch. I just _very_ carefully used the plug tap to finish the hole; lots of to-ing and fro-ing, and lots of lube.
(2 1/2 years later, this is still the only tap I ever broke :agree: :) - I hope that doesn't jinx me now :facepalm: )
 
 I haven't been able to find any 2mm screws locally. Ordering from RSA/Overseas takes weeks, so for now, I'll just make up my own ones. One partly made from excess I cut off 5mm bolts from the scrap bin:
 
 
 When parting off the screws-in-making, they want to disappear in the swarf, so I just used a spray can bottle cap to catch them:
 
 
 End of work today; not a lot to show, but a most interesting experience so far. The frame taking shape; bolted together with screws-in-making, and a countersink screw-in-making bottom right. I stopped, as my concentration was going haywire. I think I need to experiment with an angled-tip parting tool as well, as the parting excess on the screws are going to be a pain to remove:
 



More to follow when I have a bit o' time  :)
Regards, Arnold

Edited to change running engine count; there was the little matter of another rocking engine that I built as a gift before I built Fred!)
« Last Edit: August 15, 2012, 06:20:02 PM by arnoldb »
Building an engine takes Patience, Planning, Preparation and Machining.
Procrastination is nearly the same, but it precludes machining.
Thus, an engine will only be built once the procrastination stops and the machining begins!

Offline zeeprogrammer

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Re: Building Fred
« Reply #1 on: August 14, 2012, 11:17:25 PM »
I remember Fred...and the excitement!
Very glad you're reposting it here.
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Offline Dan Rowe

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Re: Building Fred
« Reply #2 on: August 14, 2012, 11:29:23 PM »
Arnold,
I will be watching with interest. I knew about this design and I have seen a few examples in steam.
It will be interesting to see how you went about the work.

Dan
ShaylocoDan

Offline mklotz

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Re: Building Fred
« Reply #3 on: August 14, 2012, 11:31:37 PM »
Fred?  What prompted you to choose that name? 

I want to know when Shrek gets his own namesake engine.  It would have to be noisy, dirty and have a lot of odd, eccentric motions.  Something like a railroad handcar with square wheels might do the trick.
Regards, Marv
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Offline rleete

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Re: Building Fred
« Reply #4 on: August 14, 2012, 11:38:04 PM »
Fred?  What prompted you to choose that name? 

Reading fail!  From the first post:  " My loco will be called Fred - after my grandfather, who provided me with a nice piece of copper plate and other odds & ends."

(just kidding Marv...)

Offline mklotz

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Re: Building Fred
« Reply #5 on: August 14, 2012, 11:41:48 PM »
Fred?  What prompted you to choose that name? 

Reading fail!  From the first post:  " My loco will be called Fred - after my grandfather, who provided me with a nice piece of copper plate and other odds & ends."

(just kidding Marv...)

Whoops.  I didn't read the whole thing because I read it the first time Arnold published it.  The reason for the name completely slipped out of my ever more slippery memory.  My apologies.
Regards, Marv
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Offline Bearcar1

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Re: Building Fred
« Reply #6 on: August 15, 2012, 12:57:51 AM »
Ahhhh, it is good to see yet another familiar crowd pleaser. This was one of my favorite builds to follow along with and I'm looking forward to seeing it all unfold once again.  :cheers:


BC1
Jim

Offline b.lindsey

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Re: Building Fred
« Reply #7 on: August 15, 2012, 01:27:00 AM »
I dont remember this one...could be failing memory though. So it will be like new to me and will look forward to following the reprise of the build log  :)

Bill

Offline arnoldb

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Re: Building Fred
« Reply #8 on: August 15, 2012, 10:22:35 AM »
Many thanks to all for your replies  :NotWorthy:

I want to know when Shrek gets his own namesake engine.  It would have to be noisy, dirty and have a lot of odd, eccentric motions.  Something like a railroad handcar with square wheels might do the trick.
Great idea Marv - all painted up in black, grey and red  ;)


21 November 2009

Some more work done on Fred.
 
 I cleaned up the screws with a jig with a tapped hole.  I slotted the countersink screws with the Dremel with a thin cutting disk. The bottom ones in the photo still need their hex heads finished. Made a booboo on the one countersink hole in the end plate; it is too deep. Fortunately this will be hidden when done:
 
 
 Then I turned up the axle bushes:
 
 
 Started turning the first wheel from HRS; that's all I have in this size:
 
 
 First wheel done:
 
 
 Then I finished another wheel. While parting it off, I went a bit quick and snapped the tip on the parting tool. So I just took the chuck off the lathe, and clamped it in the bandsaw to finish the cut. Would have put in effort with the hacksaw on the lathe, but clean out of hacksaw blades... I'll re-grind the parting tool tomorrow.
 
 Then I pressed the bushes into the frame, and cut the plain axle from piano wire. Made a mock-up assembly & stopped for the day:
 
 Both wheels still needs a final facing on the back side. I'll do that once all the wheels are complete.



22 November 2009

Today I finished the other wheels. The plans call for two separate crank webs from steel and a spacer to go between them; I just made that lot as one part out of brass. I still need to drill the web and 2 wheels for the crank pins:
 
 
 Quickly cut another piece of piano wire axle & assembled everything. I just had to see what it looks like on a piece of track  ;D :
 



28 November 2009

I made some progress on Fred again today:
 
 First up, I drilled the crank holes in the driving wheels & crank web. For this, I turned an arbor on the 3-jaw to hold the web / wheels, and set up the vertical slide & dividing head to drill the holes. I transferred the 3-jaw to the dividing head without removing the arbor to keep concentricity. Back when I made the web, I already punched it for the locations of the crank pins before dilling it through center. Here is the setup I used to drill the holes in the web; when this was done, I just clamped both driving wheels on the arbor and did them the same way:
 
 
 Then I loctited the shaft & crank pins to the web, left it to set up a bit and then added the wheels to the assembly. I just used a piece of 6mm rod to get the correct spacing between the wheels & the web:
 
 
 I also assembled the rear axle & wheels with loctite; it was easier to first put one wheel on in it's correct position, leave things to tighten up, and then add the second.
 
 While waiting for the axles to cure a bit, I gave the frame a coat of paint, and when the axles were OK, the wheels as well. I used the black high temperature paint that I bought for the boiler on it, so I shoved everything in the kitchen oven at 120deg C to cure a bit. Fortunately, it appears that the "loctite" substitute I have held up to this temperature. When I reassembled everything, the axles were just a tad stiff in the bushes, so I made a 3.05 mm d-bit reamer and gave all the bushes a run-through with it. Now the axles are nice & free running without any play. Assembled, & the reamer:
 
 
 Next up, some work on the flycranks; I sawed 4 pieces from some flat brass I have. One I laid out to dimensions, clamped the whole lot together as a bunch & drilled the 3mm hole for the axles:
 
 
 Then I just bolted them together through the drilled hole with a 3mm bolt before removing the clamp, and drilled for the flycrank pins. I pressed a piece of rod through the new hole, and took the assembly to the vice, where I filed the whole lot to shape & size. Once done, I just had to see what they looked like on the loco:
 


Regards, Arnold
Building an engine takes Patience, Planning, Preparation and Machining.
Procrastination is nearly the same, but it precludes machining.
Thus, an engine will only be built once the procrastination stops and the machining begins!

Offline steamer

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Re: Building Fred
« Reply #9 on: August 15, 2012, 11:53:52 AM »
Nice build Arnold!   Seems you have that Myford decked right out with all the goodies!

And yes....my memory cells seem to have missed this build before....glad I'm watching now...will put in less volitile memory....I hope.... ::)

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline arnoldb

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Re: Building Fred
« Reply #10 on: August 15, 2012, 04:20:59 PM »
Thanks Dave  :) - Yes, the old girl is very well kitted out.  In fact, I think the accessories I have for her is worth much more than the lathe itself!

29 November 2009

 I made the crank pins for the flycranks. Once again I deviated from the original design - mostly to accommodate my tooling, but while doing this, I added a little shoulder that would prevent the coupling rods directly touching the flycranks while running. I think Dave added little washers between the coupling rods and the flycranks when he put his Idris together. So I made the crankpins with a section of 2mm thread for retaining nuts, a 2.5mm bearing section for the coupling rod link, a shoulder, and a 2mm section to press into the flycrank. In the next photo, I'm parting off one of the pins:
 
 
 Next up, I made some nuts and filing buttons for filing the coupling rods - I didn't take photos while making these.
 Then I marked out the top of two pieces of plate superglued together for the coupling rods, drilled & reamed the holes, and trimmed the assembly to approximate size on the bandsaw. I installed the filing buttons through the holes, and clamped my milling vice in the big vice, with the coupling rod assembly clamped in the milling vice, for filing down:
 
 
 The results of today's work: flycranks with pins pressed & loctited in, nuts screwed on, a pair of coupling rods, and what's left of the filing buttons:
 
 
 And mounted on the loco frame:
 
 
 

05 December 2009

First up, I started hacking up a piece of 25mm square brass:
 
 
 Ended up with blocks for the cylinders, port block and big ends:
 
 
 Then on to the cylinders blocks; faced both blocks to size and bored the cylinders in the 4-jaw - 2 action shots; if you look carefully, you'll see some bright dots of swarf caught in suspended animation below & right to the workpiece:
 
 
 
 The results of today's work - 2 cylinder blocks; one already marked out for port & pivot holes. I got a really nice finish in the bores, so no need for lapping  :) - the spots in the bore is some "dust" from running the blocks over some 300 grit emery to get rid of machining marks:


 

Regards, Arnold
Building an engine takes Patience, Planning, Preparation and Machining.
Procrastination is nearly the same, but it precludes machining.
Thus, an engine will only be built once the procrastination stops and the machining begins!

Offline arnoldb

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Re: Building Fred
« Reply #11 on: August 15, 2012, 07:44:18 PM »
06 December 2009

Finished off the cylinder blocks; I nearly got caught by an error on the plans. I'm basically building to the metric sizes. Dave specified the metric hole in the cylinder block for the trunnion pin as 2.5mm, but the pin itself as 2mm - that's a big difference. The imperial measurements are both specified as 3/32" - so I just settled on 2mm for both the holes and the pin. Conveniently, my 2mm center drill goes to exactly the right depth before starting to cut for a 60 degree center, so it made getting the correct depth easy. Here a photo of work on one of the cylinder faces - trunnion hole drilled 2mm, and the undercut faced off:
 
 
 After finishing the other cylinder the same way, I moved to the drill press & drilled the port holes:
 
 
 Then I set up the lathe with the vertical slide and flycut & milled the piece of brass for the port block to size:
 
 
 
 With slightly un-square (is that a word?) top and bottom on the port block from the bandsawing, this is the method I used to set up to mill them square - the drill sticking out at the other end of the vice is to keep spacing correct across the jaws:
 
 
 I stopped work on Fred today with the finished cylinder blocks, and the port block ready for layout and some very deep drilling... :
 



07 December 2012

I received a parcel in the post; inside was a Christmas card and a neatly wrapped present. I was expecting the parcel and some of it's contents, but not all the extras it contained... Rob - Thank you very, very much indeed mate!   :NotWorthy: :NotWorthy: :
 
 



10 December 2009

Started off with marking out the port block:
 
 
 Dave Watkins says to cross drill the port holes first, then stick brass pins in the holes, then drill the passages in the block - the brass pins are to prevent deflection/bite-in when the passages reaches the port holes. I did it the other way around; I don't have suitable brass pins, but I do have a lot of 2mm bronze brazing rod. This is tougher than brass, so could still cause deflection on the deep passage holes, so I drilled the passage holes first, and then the port holes. Some deep drilling on the lathe - my cheep 'n cheerful drill press is not accurate enough... :
 
 
 
 Next up the port holes & pivot hole - for this the drill press is good enough, as these holes are not so deep. Notice the brazing rod pieces sticking out of the passage holes:
 
 
 Bottom section of port block done; notice the half-drilled notches in the pins where the ports meet up (the one on one end just barely  :-[ ) I wasn't overly concerned about getting the pins out after drilling, as the brazing rod is pretty tough - they came out with a couple of to-and-fro wiggles with a pair of pliers to loosen them:
 
 
 Next up, flattened the cylinder faces on some 1200 grit W&D on a glass plate (the tapping chart is below the glass plate):
 
 
 The top part of the port block was just turned to size in the lathe & parted off. Then marked out for the inlet & exhaust ports as well as the "through" ports that meet up with the reversing valve. - Drilling the ports:
 
 
 After that, I started on the threaded steam inlet on the side, and promptly made a mess-up of that by over-threading and thus stripping out the threads. Fortunately the exhaust side was not done yet, so I switched around and re-did it - successfully this time. The exhaust needs (in my case) a 3.3mm hole, so I turned, drilled & soldered a brass bush in the miss-threaded side for the exhaust - see red circle in picture. It came out OK, so next up, I used a 2mm center drill to "stretch" the passage connections (they don't align up - according to the plans); Dave mentions filing some fillets to do this, but the needle files I have is a bunch of junk, so I used the center drill; crude yes, but effective. Also, there are some machining grooves left from parting off - I left them, as in my opinion they would help wick the solder through and isolate the ports when soldering. The other face is as smooth and flat as I can get it.
 
 
 Next up, I turned & threaded the stud that works to keep the reversing valve seated, screwed it into the block, and put the top of the block on; the stud helps with alignment of the top part of the block to the bottom. As the stud was in place, i used some spacers and basically locked the top part of the port block to the bottom; then clamped the whole lot by the spacers in the vice, and soldered it together:
 
 
 Final result after getting rid of excess solder - some tricky finger-manipulation to close and open holes, and blowing by mouth into the port block makes me think that everything that must be sealed is, and that the passages were not blocked by solder.:
 
 
 
 Regards, Arnold
 
Building an engine takes Patience, Planning, Preparation and Machining.
Procrastination is nearly the same, but it precludes machining.
Thus, an engine will only be built once the procrastination stops and the machining begins!

Offline arnoldb

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Re: Building Fred
« Reply #12 on: August 16, 2012, 02:59:52 PM »
12 December 2009

First up, cut a piece of brass flat bar and marked out the top section of the reversing spool valve:
 
 
 Hacksawing to rough shape - a lot of filing followed, but I did not take a photo of the end result:
 
 
 Some brass turned to diameter & laid out for the bottom section of the spool valve. I used a 1mm center drill to just dimple the front of the stock to get the center point, then compasses to mark out the radius. A light scribe with the cutting tool tip (has to be dead on center) by cranking the cross slide marks the first cross line, then, taking advantage of the myford's flat ways and a square, rotate the chuck with the line vertically square and mark again with the cross slide:
 
 
 Then drill the 2mm center hole, and part off using the shank of a broken 1.6mm drill bit in the tail stock to catch the workpiece:
 
 
 Made a little jig for the drill press; just some offcut mild steel slightly wider than my toolmaker's clamp; drilled a 2mm hole part-way through it & stuck a bit of 2mm brazing rod in the hole & clamped in the drill vice. The spool bottom's center goes over the pin, and I clamp it with the toolmaker's clamp. A 2mm center drill is put to use to drill curve approximations in the workpiece:
 
 
 In use:
 
 
 And done; a little filing required still... at the top of the photo is a partial piece of the top of the valve after filing that I forgot to photograph earlier:
 
 
 Next up, I turned the end of a bit of ~5mm aluminium down to 2mm for a tight fit for the spool valve's top and bottom parts. This is for alignment while soldering them together, without getting everything stuck too much to the pin. A trial check before soldering:
 
 
 Some 0.5mm solder rings & pieces put on the top part - if you look carefully, you might also see 6 light punch marks around the perimeter to keep "just" a little clearance for the solder to flow between the 2 parts:
 
 
 Other part was put back on top, and I just heated the whole lot with a butane torch. When the solder started flowing, I pressed the parts together with a heavy piece of mild steel placed on top, and let the lot cool. End result (too much solder  :-[ ):
 
 I then spent some time with a scribe & drilling bits in a hand-held chuck to clean out the excess solder manually.
 
 Next up, it was on to the big ends. Some brass bar - long enough to make both big ends centered in the 4-jaw and turned down on one side; I then drilled & tapped the end M3 for the 3mm stainless steel connecting rod.
 
 
 Lazy rotter that I am, I then just fit the collet chuck & reversed the part for doing the other end. This could easily spell disaster, but my cutting tool is nice and sharp, so no problems. Best would have been to use the 4-jaw again and just spend the time to center everything... :
 
 
 Next up was drilling 1.4mm holes for threading for the big end bolts. The Myford's a bit slow for drilling these holes, and the pedestal drill, while capable of reaching the speed needed, just not accurate enough. What to do? I have drilled a couple of thousand of holes in PCBs with my Dremel and it's small press; not entirely accurate either, but might just do the job. So I mounted the parts in the myford's milling vice and gave things a go with the Dremel in it's stand:
 
 Worked a charm  :)
 
 I used a slitting saw to slice off the end caps of the big ends; much less work than trying to saw & file to size:
 
 I had to spend a couple of minutes searching for the first one slit off through the swarf behind the lathe  :-[ ... - the second one was prevented getting flung away by stopping _just_ short of it coming off, manually breaking it off & filing away the left-overs.
 
 Rob (Thanks Mate!!!  :NotWorthy: ) sent me some 10BA taps. These are worth more than gold to me, so I first (crudely, but effectively) made a tapping guide and tap holder to tap the big ends from HRS I have lying around. Clamped the workpieces in the Myford's milling vice and went for it, with very nice results. First photo shows the setup, guide & holder. Next is a close-up of the result:
 
 
 
 Finally, the results of today's work... Not much to show, but most satisfying  :)
 

Regards, Arnold
Building an engine takes Patience, Planning, Preparation and Machining.
Procrastination is nearly the same, but it precludes machining.
Thus, an engine will only be built once the procrastination stops and the machining begins!

Offline Dan Rowe

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Re: Building Fred
« Reply #13 on: August 16, 2012, 03:26:34 PM »
Arnold,
Some very interesting methods you are showing.

I am having a hard time seeing how your tap guide works. If the brass blocks had been set flush or slightly below the top of the vise than one block with the hole in it would set on the top of the vise jaws would work other wise it seams a bit tippy with a large mass attached to the tap.

I tap a lot of holes in the 10 BA size range and I use a commercial tap guide which has kept my tap breakage to a minimum. For the small ones I do not use the t handle I use the 1/2" shaft for fine control of the tapping torque.

Dan
ShaylocoDan

Offline arnoldb

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Re: Building Fred
« Reply #14 on: August 16, 2012, 08:11:57 PM »
Thanks Dan  :)

Some of the methods shown were pretty crude; I had minimal experience back when this build was done, but I must say I learned a lot from it.  It was mind over matter; I really WANTED to build this locomotive and I wasn't going to allow having a minimal set of tooling stand in my way. 

Yes; the tapping was slightly "tippy" back then - I used the block with the hole in it pressed down firmly with my right hand on top of the workpieces as guide, and then tapped the holes with my left hand.
I'm normally right-handed, but using my left gives me a better feel for tapping small threads - something I do as a matter of course nowadays.
I have - of late - actually started using a 12mm (1/2") shank for M2 and smaller taps - that does give better control  :ThumbsUp:   
One of my tuits is to build a proper tapping stand, but I've been deferring that as I might go the whole hog and build it as a sensitive drill combination  :thinking:

Kind regards, Arnold
Building an engine takes Patience, Planning, Preparation and Machining.
Procrastination is nearly the same, but it precludes machining.
Thus, an engine will only be built once the procrastination stops and the machining begins!

 

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