The end result is that I have made the original 22 mil excess play a more tolerable 10 mil. The intended gear mesh is more closely retained and there is now almost ZERO chance of gears ratcheting past one another.
Now that this gap has been reduced, I’ll experiment going back to Delryn main drive gears.
There’s a few loose ends to talk about.
On the down side, these plates make assembly and disassembly a bit more tedious (but not much).
In order to remove the power truck, I have to remove the plates. Also, the plates are now proprietary instead of universal. So I marked each one so I could keep track of which goes where.
Will this work for other Kumata locos? (All Kumata locomotives use this gearbox except the Centipede)
Sure…. But there is one caveat.
There is no problem for the EP-2 because each EP-2 cab has only one gear box and it is charged the same as the shell. But other Kumata locos have two gearboxes- and each is charged to a different rail.
In this photo, the left gearbox is charged to the rest of the frame. The right gearbox is insulated and would short on the frame.
So if we made this mod to another KMT loco (like the RS-2 in the photo above) since the frame is charged, that means the insulated gearbox is now a greater shorting risk with the shell because we have added thickness to the gearbox.
If this will work at all, the solution will probably be to use nylon M1.4 screws on the insulated gearbox (assuming they will fit) and/or Kapton tape.
