Here is a project that has been on my back burner for a long time, but is now at long last completed. This is to convert a ScaleTrains SD40-2 to Proto:87 wheels. What made this a bit of a trick was that the ScaleTrains diesels use 1/2 axle wheelsets with 40" 2mm diameter axles, however the NWSL catalog does not have any P:87 conversion wheelsets with 2mm axles (only 1.5mm and 3/32"). I recently found out that they do have a 2-wheel wheelset with a 2mm axle that can be ordered with 40" P:87 wheels, which is usable for diesels if one cuts the wheelset in half. The only real downside is that one wheel of each wheelset has the insulated bushing, which makes it unusable in a loco, and so you need to buy twice the number of wheelsets as you would otherwise need
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So aside from the cost and the need to cut axles, the rest of the conversion process is pretty straightforward. The step-by-step is basically as follows. First, disassemble the loco to get at the trucks, and then disassemble the trucks, taking the factory wheelsets (with their NMRA RP25 code 110 wheels) out of the geared center axles.
Here are a few pics of the trimmed axles. I had to make sure to keep the axle length the same as the originals. I also had to shorten the axles on the face side of the wheels. Importantly, the cut ends of the axles must be filed smoothly to remove any/all burrs.
When installing the new wheels, it is vital to set the correct back-to-back distance. The tolerance on this is very small, so care is essential.
Here are the wheelsets installed back into the truck frame:
The first truck re-assembled, one more to go:
Re-assemble the loco and get it back onto the rails. Watching this glide thru the P:87 turnout is a real trip -- makes it worth the extra work! 😉
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Thanks for following!
Ed
