Getting an old MDC Climax running again

uhrwerk Feb 4, 2021

  1. Mike VE2TRV

    Mike VE2TRV TrainBoard Member

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    Actually, I'm going the epoxy route, as a test, on the partially completed one. It's drying now as I type this.

    The wire trick won't work with this one, as it's a very small plastic part that goes right on the motor shaft (the motor on my Shay is exactly like yours, so you should have an idea how small that shaft is).

    After I set the motor aside to let the epoxy set, I took the sideframes off the geared side of both trucks and turned the drive mechanism manually. Lo and behold, no drive sticking! If the epoxy thing holds up, I might have a couple of running Shays in the near future.

    I suspect that the gears on the outside shaft aren't synchronized and that's what's going on. The way the engine lopes along before the motor coupling fails reminds me of Proto diesels with cracked axles - when the axle is cracked, its diameter increases slightly, putting it out of sync with the rest of the drive mechanism. That makes the engine clunk along. In the case of the Shay, it's probably poor quality of the plastic shaft gears that don't mesh with the wheels properly. I'll try whittling down the gears on three of the four wheels, leaving one to drive the cylinders. And cross my fingers...:unsure:

    Thanks for pointing me in the right direction, uhrwerk. :)

    The extra coffee helped too...:coffee:
     
  2. uhrwerk

    uhrwerk TrainBoard Member

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    Yep, that's what I drilled in to, so I know it will work! I was pretty intimidated by it also, but I found the shaft was mild steel rather than tool steel like drill rod stock, and so I was able to drill through it with a tiny drill bit and a steady hand (I rest both hands on the table while doing this kind of work). I'm glad epoxy worked for you, definitely easier! Make sure you keep the mechanism lubed so the epoxy doesn't experience a lot of shear stress. Roughing up the shaft surface may make it hold better if it breaks free in the future.

    Yes, I can't even imagine how it would even be possible to get all four axles, the side shaft gears, and the central drive gears synchronized. And then given the slop in the mechanism, I can't imagine it staying synchronized for more than a moment before it would bind again. Since universal joints are not constant velocity, whenever your Shay goes around a curve, synchronization would be lost because both the central shaft and the side shafts have u-joints and would flex by different amounts. In a real Shay, of course, there's no central drive shaft, but even then the non-constant velocity of the side shaft u-joints must be an issue, requiring significant slop in the side shaft mechanism to keep it from binding. Of course there the gears are steel and can take the high loads. I seem to recall when I've been near the real things that the gears clank a bit - this would be why.

    I have two HOn3 and one HO Shay kit in the stash from my dad, I think, so I'll be building some in the future. I think there's also a keystone static Shay kit with a NWSL powering kit, not sure if it's HOn3 or HOn30. That looks like quite the challenge.
     
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  3. Mike VE2TRV

    Mike VE2TRV TrainBoard Member

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    Update!

    I filed off the teeth on the wheel of one axle of each truck of the uncompleted kit (frame, motor, drive, trucks) and the results are encouraging. It travels a whole foot before jamming. So one of the two remaining axles will get the other wheel's teeth filed down, leaving one axle driving the cylinders - so no conflict between axles (if one alone gets into conflict with itself, I'd say it's as crazy as I am...:confused:).

    But even more encouraging is that the epoxy holding the little plastic adapter hasn't failed after the drive jammed as above.

    Those Shays might run after all!:)
     
  4. uhrwerk

    uhrwerk TrainBoard Member

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    Mike, that's great! Please keep me posted on your progress debugging the mechanism. I am very interested as I have a couple of those Shays to build. I have disassembled the Climax and primered it, but no progress beyond that - I've been working on other hobbies. I need to get some paint to paint the boiler and water tank a nice grey black.
     
  5. Mike VE2TRV

    Mike VE2TRV TrainBoard Member

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    :LOL:... I know exactly what you're talking about...

    Work on the Shay is basically an on-and-off schedule. But recent results are giving me motivation to put a little more "on" and a bit less "off"...;)
     
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  6. uhrwerk

    uhrwerk TrainBoard Member

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    I cut out the perfectly triangular wood stack on the climax last night and need to think what I want to replace it with.


    Sent from my iPhone using Tapatalk
     
  7. uhrwerk

    uhrwerk TrainBoard Member

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    [​IMG]
    Shot it with a mix of nato black and panzer grey. In retrospect, wish I’d used more grey but I can lighten it up when I weather it.


    Sent from my iPhone using Tapatalk
     
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  8. uhrwerk

    uhrwerk TrainBoard Member

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    Did a little more painting and weathering; installed couplers as well. Can't seem to upload pictures inline anymore, not sure what's up with that.
     

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  9. Mike VE2TRV

    Mike VE2TRV TrainBoard Member

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    Nice paint job! :cool:

    You're not alone.

    I found a workaround: upload your image as usual, put your cursor where you want your photo, then hit the Image button (first button to the right of the smileys button) and copy the link to your photo, click Insert and you're done.

    It's just that easy. Any simpler and you'd need duct tape. :D
     
  10. Shortround

    Shortround TrainBoard Member

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    Awe! The wonders of 10.
     
  11. uhrwerk

    uhrwerk TrainBoard Member

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    Calling it done - how is your Shay going Mike?

    [​IMG] [​IMG] [​IMG] [​IMG]
     

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  12. Mike VE2TRV

    Mike VE2TRV TrainBoard Member

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    Nice result!

    As for my Shay, it's put aside for a while, pretty hectic around here. Planning on buying a brand new car soon, while keeping the old tank up and running, and doing some extra work at home...

    One of these mornings, early (my best time), that Shay will get back into the desnag department. Once I've figured out how to get it to work, I'll copy the solution to the already-completed Shay that's currently under (plexi)glass as a static display.
     
  13. uhrwerk

    uhrwerk TrainBoard Member

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    So one question I had for you - you decided to file off the teeth on the gears on the axle, or the gears on the siderod? You got it to run with only one gear? I am curious what works best before I build one of my dad's shays.
     
  14. Mike VE2TRV

    Mike VE2TRV TrainBoard Member

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    I filed down the teeth on the outside of the wheel.

    One gear per truck, so far, and on my partially-assembled guinea pig, I don't have the connecting shaft on yet.

    It still sticks at one point (after about a foot or so of moving; before, it was a few inches), so one of the two is the culprit. The next step will be to pull one sideframe off at a time to isolate which suspect is the actual perpetrator.

    I'm still considering the possibility that one of the transmission gears might be the origin. Since it ran rather nicely with neither of the sideframes on (not on the track but in my hand and powered via alligator clips), that's unlikely. That still would be relatively easy to diagnose by removing one of the dogbones underneath the unit.
     

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