When you're remotoring a loco..???

Model Railroader General Discussion (Model Railroader)
1

I have been looking into remotoring my PFM Santa Fe 4-8-4. Here’s my questions. When looking at the Precision Scale gearboxes, included is a 3mm axle with a grea installed in it. So to install the PSC grearbox do I have to remove the drivers from the old axle and re-press them on the new axle? If this is what is needed, then:

  1. How do you get the drivers off the old axle without damaging them?
  2. How do you press them on the new axle without damaging them?
  3. How hard is it to re-quarter them once they are on the new axle (assuming I didn’t destroy them in the first 2 parts!)?
  4. What gear ratio do I want??

Now the for the motor…

  1. How do I pick a motor!?

Thanks guys…this is just something I hear people talk about, but I have never really understood it…my goal would be to end up with something similar to this…
http://www.tcsdcc.com/decoderpics/Brass%20by%20Vander%20Meer/m1_decoder_in_brass_loco_instala.htm

2

Professional’s that do this kind of work generally use NWSL gear boxes, motor’s and quartering jig’s. You might want to start there.

Larry, at PSC, used to do this kind of work at Caboose Hobbies. He might talk to you.

3

NWSL makes a wheel press just for these purposes. I’ve found mine indespensible. I am certain other companies make them as well. The object is to apply equal pressure all the way around the wheel. Prying on one side at a time will either bend the axle or warp the wheel.

Once again NSWL makes a driver quartering tool. BUT quarter them before you press them all the way on.

These two things work together to determine the top speed and low end performance of the model. Generally 4-8-4’s didn’t have a good low end. I know GN tried to use retired ones for switching. It was an experiment that lasted only a day or two. Anyway back to the topic - First determine the desired top speed for the loco. Calculate the number of revolutions needed for that speed based on the sized of the drivers. Take that number back through the gear ratio and you should have the required rpm for the motor. There should be several gear ratio/motor combinations that work.

4

If you’re going to do a re-motoring/re-gearing job, in my opinion, the best place to go is NWSL and the best place to start is their catalogue. It’s obviously got all the listings for motors, gearboxes, and drive train parts, but it’s also loaded with information and tips on how to do what you’re trying to do. Good info on selecting the best motor and gearbox combo for your particular loco and advice on getting the optimum performance out of any engine. Also a section on some useful tools for the type of work that you want to do. Well worth the price.

Wayne

5

before removing the wheels mark the shaft and driver with a cut from a back saw,
you can push, or pull the drivers off, but dont try to turn them. as the shaft has a splin, and can get stripped. also see mr mag, (may 2002) they hav an artical modifying and updating a 2-8-0 its like 5 or 6 pages on just this type of thing
hope this helps

the bud