Author Topic: Building Kozo's New Shay locomotive  (Read 194050 times)

Offline Roger B

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Re: Building Kozo's New Shay locomotive
« Reply #510 on: February 16, 2015, 07:30:29 PM »
Great stuff Chris  :ThumbsUp:  :ThumbsUp: . I also don't use my quick change tool holder when parting. The extra overhang and the dovetail seem to add too much chatter and vibration.
Best regards

Roger

Offline crueby

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Re: Building Kozo's New Shay locomotive
« Reply #511 on: February 17, 2015, 06:06:27 PM »
All right, back in the shop again today. Started on what Kozo calls the 'square pieces' for the universal joints. These are steel square rings that hold the pins for the u-joints. They start out as a piece of round bar, drilled/bored on the lathe... (photo 1)

Then over to the mill to square up the outside with the fly cutter. (photo 2)

The original curve is left at the corners - this will fit the cover ring in a few steps. (photo 3)

Back on the lathe, parted the square sections off to length. (photo 4)

Each section was then clamped in the mill vise ant the middle hole taken out to square, so that the dimensions match the outside width of the coupler horns. (photo 5)

With the squares made, it was time to make the retainer rings that go around the squares, and hold the pivot pins in place. The rings started as a length of brass bar, drilled/bored out to match the original diameter of the square sections. I took the hole out to size just deep enough for one ring at a time, so that it would stay strong enough to do the work on the outside - otherwise it would be like machining a long thin wall tube. (photo 6)

After boring the inside, the outside was turned to a curved profile, finished smooth with a file. Maybe I can go into business making cheap brass wedding bands... Anyway, after shaping the outside, the rings were parted off from the bar. (photo 7)

The last photo shows the rings and square pieces test fitted - the rings are a snug fit over the curved corners of the squares.

Next up will be to make the pivot pins, which go through the center of the flat sides of the squares and into the holes in the horn couplings. The heads of the pins are held in place by the brass rings. The rings will get retaining screws into the corners of the squares. Should be interesting to see it all together...

Offline Roger B

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Re: Building Kozo's New Shay locomotive
« Reply #512 on: February 17, 2015, 06:52:30 PM »
Interesting stuff  :ThumbsUp:  :ThumbsUp: I only know the automotive type joint with the cross on the inside  (I broke a few on my rally car  ::) ) Still watching with interest  :wine1:
Best regards

Roger

Offline crueby

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Re: Building Kozo's New Shay locomotive
« Reply #513 on: February 17, 2015, 08:55:12 PM »
Interesting stuff  :ThumbsUp:  :ThumbsUp: I only know the automotive type joint with the cross on the inside  (I broke a few on my rally car  ::) ) Still watching with interest  :wine1:

Did the joint on the rally car break before or after the wall/cliff/tree was encountered?!

Offline crueby

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Re: Building Kozo's New Shay locomotive
« Reply #514 on: February 18, 2015, 02:35:14 AM »
Here is the sequence for the rest of the u-joint assemblies. Last post I had gotten the square and round shell pieces done, so I got going on making the pivot pins. They started out as a length of stainless rod, and turned the ends down and threaded them at the tips on the lathe. The threaded portion is only there to hold it to the fixture to shape the heads, it will be cut off after that. (photo 1)

Second photo shows the pile-o-pins, 16 are needed, made a couple spares in case I Murphied one or two...

The heads of the pins need to be radiused to fit under the outer retaining ring. To do that, a little fixture is made from some scrap bar stock, with shank turned to same diameter as the inside of the retaining ring, and a flat milled in the side the same distance from center as the flats on the square inner ring. The pin is put through a hole in that, and a nut on the inner side to hold it in place. Then its a simple session of turning it down to the proper radius. Once I got the setting from the first one, I zeroed the handwheel there to make the rest go quick - bolt in the pin, take several passes down to zero, remove the pin and cut off the threaded part... (photo 3)

Last thing to do before assembly was to drill the holes in the squared ring for the pivot pins. Set up first one in the vise with one edge aligned with the edge of the vise, centered for the hole, then could crank through the rest at the same setting. (photo 4)

Fifth photo shows all the pieces for both drive shafts. The upper one is assembled, the lower one still in pieces. On the left is one of the squared rings with one of the horn couplers in place. The pins on that one are cut to length, the pins laying on the right are still uncut.

Next shot shows a closeup of the assembled joint - you can see the pin heads under the outer ring. Assembling that is a little fussy, since the pin heads need to be all aligned with the high spot running lengthwise so the ring will slip over them. Without letting any fall out. Again. Oops, again...

Seventh shot shows both shaft assemblies all together - all that needs to be done is to drill/countersink for some small screws through the outer ring into the corner of the squared ring, so that the outer ring can't slip off.

Last photo shows the shafts slipped onto the ends of the crankshaft. Just need to cross-drill the ends for pins to hold them in place. For now I'll run some small (2-56 or 1-72) bolts through the pin holes so I can assemble/disassemble it quickly while making the rest of the engine. The u-joints work very well, nice and smooth, with more than enough angle possible for the trucks to pivot. I've never made u-joints this style before, always had done the car-style. For small models I like this type, the parts are not quite so tiny on the pivots.  Not sure why the Shays had this style over the inner-pivot style, maybe was easier to maintain in the field, and could be made beefy to take lots of torque.



Offline b.lindsey

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Re: Building Kozo's New Shay locomotive
« Reply #515 on: February 18, 2015, 02:42:48 AM »
Well I was wondering how all that would work and now I see. Good thing you got them all together Chris, the shop gremlins would LOVE all those little pins :)  Nice work on the u-joints and fun to follow along.

Bill

Offline crueby

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Re: Building Kozo's New Shay locomotive
« Reply #516 on: February 18, 2015, 02:50:51 AM »
Well I was wondering how all that would work and now I see. Good thing you got them all together Chris, the shop gremlins would LOVE all those little pins :)  Nice work on the u-joints and fun to follow along.

Bill

Lets see, how did it go in that movie... dont feed the gremlins small engine parts after midnight , dont get cutting oil on the gremlins,... something like that!

The wood floor in the shop is great for finding small parts/springs/etc that TWANG off in some odd direction, except they always go under the compressor, behind a cabinet, into the trash can that is full (never when it is empty)...

Offline ths

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Re: Building Kozo's New Shay locomotive
« Reply #517 on: February 18, 2015, 07:32:26 AM »
Chris, the wedding rings look fantastic, especially on square fingers. Are they all the same outside diameter? Do they need to be? Fully assembled, well, I like that shot very much. Cheers, Hugh.

Offline crueby

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Re: Building Kozo's New Shay locomotive
« Reply #518 on: February 18, 2015, 01:18:21 PM »
Chris, the wedding rings look fantastic, especially on square fingers. Are they all the same outside diameter? Do they need to be? Fully assembled, well, I like that shot very much. Cheers, Hugh.

The critical dimension on the brass rings is the inner diameter, so it is a snug fit on the squared rings and pivot pins. The outside diameter was turned to the same starting dimension on all of them, there was probably a slight variance that crept in during filing the curve into them but that does not effect how they work.

Offline crueby

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Re: Building Kozo's New Shay locomotive
« Reply #519 on: February 18, 2015, 04:10:28 PM »
This morning was catch-up-on-little-stuff time: pinned the last connections on the shafts, ran in retaining screws on the u-joint rings, lapped the main bearings, and test fit the whole thing on the loco. The TimeSaver lapping compound (yellow) that someone here recommended worked fantastic - I got the trial set of different grits, it looks like it should last for a LOT of models since it does not take much to mix up enough with oil for small bearings. It works very quickly, and left a smooth running set of bearings. I think I will go back and relap some of the connections on my twin-beam engine, see if it will clear up the sticky spot that one has.

First photo shows drilling/tapping for the retaining screws on the outer u-joint rings.

Rest of the photos show it all assembled on the loco. Good point to sit there with it and make train noises!
Next steps in the book are to make the pistons and conn-rods.

Offline b.lindsey

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Re: Building Kozo's New Shay locomotive
« Reply #520 on: February 18, 2015, 04:30:20 PM »
Awesome Chris!! Getting closer by the day.

Bill

Offline Roger B

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Re: Building Kozo's New Shay locomotive
« Reply #521 on: February 18, 2015, 06:41:56 PM »
Interesting stuff  :ThumbsUp:  :ThumbsUp: I only know the automotive type joint with the cross on the inside  (I broke a few on my rally car  ::) ) Still watching with interest  :wine1:

Did the joint on the rally car break before or after the wall/cliff/tree was encountered?!

Actually the joints were also the pivots for the swinging arm suspension so they took the suspension loads as well as the driving torque. The ears used to break off the flange to the differential until I exchanged then for the larger ones from the 6 cylinder version (Triumph Herald and Vitesse for the British readers).

Still enjoying the build  :praise2:  :praise2: not far to go now  :)
Best regards

Roger

Offline Tennessee Whiskey

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Re: Building Kozo's New Shay locomotive
« Reply #522 on: February 18, 2015, 07:06:03 PM »
Crueby, I haven't seen joints that nice since the last time I was on Willie's bus 8). Seriously,  great looking shafts and joints.  I have seen that type of joint on some type of farm equipment somewhere,  I'm thinking it might have been an old hammer mill  :thinking:. Loved the broaching method on the shafts BTW  :ThumbsUp: :ThumbsUp:

Eric

Offline crueby

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Re: Building Kozo's New Shay locomotive
« Reply #523 on: February 18, 2015, 08:09:47 PM »
Crueby, I haven't seen joints that nice since the last time I was on Willie's bus 8). Seriously,  great looking shafts and joints.  I have seen that type of joint on some type of farm equipment somewhere,  I'm thinking it might have been an old hammer mill  :thinking:. Loved the broaching method on the shafts BTW  :ThumbsUp: :ThumbsUp:

Eric

Didn't you work as a roadie for Dr Teeth & The Electric Mayhem??   :o

Offline Tennessee Whiskey

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Re: Building Kozo's New Shay locomotive
« Reply #524 on: February 18, 2015, 10:42:45 PM »
Well, Miss Piggy and I were pretty tight until she found out what I cook for a living  :lolb: :lolb:

E

 

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