Of the 409 threads that come up when I did a search for this engine, I was unable to find any mention of a drive shaft problem that I have encountered during a rebuild of one of these kits in the several dozen that I reviewed.
So, my apologies to all for starting thread #410.
This kit was previously assembled by someone who really didn’t know what they were doing. Nothing was broken, but parts were not tighened down, and some drive shaft gears were mounted improperly. I replaced all gears with NWSL parts and everything was going well during assembly. The gear box worked smoothly when I tested the motor on DC. The truck gears rotated smoothly when I tested them. I did remove all but one gear on the outer driveshaft. Nothing sticking or jamming, I was happy.
I must also mention that I have followed the advice of Garretfan at the following link: http://www.modelrailroading.nl/ProjectShay/ShayIndex.html I do not have the book published by Oso. All aspects of the rebuild seem to be covered by Garretfan.
My next plan was to place each truck in turn on the frame and test the truck hooked up to the gearbox. This is where I found a little problem. The female end of the coupling that fits onto the truck worm shaft doesn’t fit. The coupling has a hole diameter of 2.25mm and the truck worm shaft has a diameter of 2.15mm.
I have placed a call to NWSL to see if they have a solution to this problem, or have even encountered it before. No answer, so hopefully, they’ll call me tomorrow. In the mean time, I thought I’d post this on the forums to see if anyone else had encountered this problem and had come up with a solution.
Again, my apologies for starting a new thread. Any suggestions will be gratefully
I built one about ten years ago and all parts fit. So it would seem to me that you have a missing part (the piece that goes on the truck worm shaft that goes in the universal coupling) or someone decided to use different parts, and now they won’t fit together. You might have to wind up replacing the whole universal coupling. Both male and female parts, each with a shaft diameter appropriate to their shaft.
Thanks for your reply, gandydancer.
No parts are missing. What I have been doing is replacing all MDC parts with NWSL parts. Unfortunately, it’s the drive shaft cup that doesn’t fit tightly onto the worm shaft. There’s a difference of .10mm between the shaft and the cup hole. All other parts have fit perfectly and operated perfectly. Just have to solve this one little dilemma.
On my Shay, the wormshafts are made of brass. Maybe you can squeeze the end of the shaft to flatten it out just enough for the universal cup to fit on there? And if it needs anymore help holding in place, some super-glue should finish the job.
Depending on the shaft material, you may be able to gain some diameter by “upsetting” it - that is, rolling it between two mill files while applying pressure.
Wayne
Is it possible to get .10mm by doing this, Wayne? The shaft is 2.14mm in dia.
Grampy1
I recently installed the NWSL upgrades to a “RTR” 2 Truck Shay, I ran into the exact same problem your are experiencing. The brass worm shafts are a smaller OD than the NWSL coupling, my solution was to simply to use Zap A Gap to glue the couplings to the worm shaft and let dry for a day. I did this in January and the shay runs great with no issues concerning the glue worm shafts and the glued couplings. A shaky video of my 2 truck after the upgrades…
http://www.youtube.com/watch?v=jtzVXAUVHe8
I also referenced Garretfans website before doing the upgrade, a very good resource for us geared steam fans. [tup]
Zap A Gap, in case your unfamiliar, is exactly that, a thick heavy Cyanoacrylate designed to fill gaps, it worked great.
I’m not really sure - that translates to about .0039". If the shaft is brass, you could apply solder to build-up the diameter at the end, then turn it down to the required size by chucking it in your Dremel and using a needle file, applied lightly against the spinning shaft.
Another alternative is to use some shim brass to build-up the diameter. It should be available at any decent automotive supplier. Simply cut a strip to a suitable width, put a “curl” in it by dragging it over a sharp corner, then snick-off the required length to length to wrap around the shaft (about 6.7mm)
I have one of these from back in 1995 that I am just now getting around to finishing construction and painting…I have a bull gear on order thru my L.H.S…but of course it is on back order thru Walthers.[(-D][:(!]
Thank you all for your replies. What a resource this site is. [:)]
Wayne, I like the solder idea. A good solution that I never thought of. I also like Ron’s idea of using filler. I think I’ll put some solder on the ends of the shafts, then gnurl the shafts as Wayne suggested and then use a bit of filler to ensure a firm grip. More fussing about, but it’ll be worth it in the end.
Bummer about the parts wait, Dennis. I live in a hobby shop void, so I order directly from manufacturers. The longest I’ve waited for a part is two weeks. Good luck.
Great site you have, Ron. Still haven’t modified the turntable we discussed a few months ago, but I will. I’m also an MDC fan and have several of their 3in1 kits to assemble as well as another two truck and a three truck Shay. Lots of fun ahead.
Thanks again everyone. Now, back to reassembly of a three truck Heisler. It’s decoder time. [:)]
Take care all and have fun.
Roy