Are Brass Motor isolation kits available?

Model Railroader General Discussion (Model Railroader)
1

I have an overland diesel engine that I have installed two decoders in but blew them both in minutes on the layout. I was told I needed to isolate the motor before doing this. I see that the motor is right to the frame and not isolated so now I understand that but I wanted to know what kind of kit is there available for doing this? Or What will I need to do to isolate the motor? Thanks

2

Sorry, no such kind of animal available. What you can do is remove the screws that hold the motor in place and use some 3M double sided foam tape to hold the motor in place instead.

3

My “kit” consists of:

  1. A multimete, or a DC powerpack in a bind

  2. CA

  3. .010" styrene strips (I found electrical tape to be too much of a pain to work with, and double sided tape would short the motor against the shell)

  4. xacto knife, with #11 blade

  5. #50 drill and 2-56 tap*

  6. stranded “jumper” wire for the motor brush that was fed from the frame

  7. Nylon 2-56 Screws (like from Kadee)

  8. 1/8" 2-56 screws (to hold the jumper wire to the frame*

*Only used if I can’t mount the jumper wire between the motor mount and the frame.

The method I used was this (note: these were steam locos, some steps may not be necessary):

  • Remove the motor from it’s mount

  • remove driver cover plate

  • remove drivers

  • File down front motor mount about .045" so wire worm gears can mesh*

  • File down rear mount about .015"

  • File down any other metal surfaces that may come in contact with motor about .015"

  • Above measurements are approximate, you really only need to take offenough material so that the gears mesh correctly

  • Glue .75"x.010"x.188" styrene strip to the REAR motor mount, and drill #50 holes as necessary to clear screws

  • glue short (about .25") .010" styrene to other exposed metal surfaces that may contact motor

  • cut a piece of wire about 4-6" long, place UNDER styrene strip*

  • place motor on top, use METAL screw(s) to tighten to frame (nylon screws strip out at this point)

  • replace drivers and driver cover plate

  • check gear mesh, if it’s good remove screw(s) and replace with nylon ones, tighten screws to get tighter mesh, or file down mounting point a bit more

  • Check for open circuit using multimeter or track power

  • (assuming track power method) If the motor doesn’t run, test that the jumper works by touching it to the correct brush - c

4

Yes, there is. It’s called Silicone gel and it works like a charm. Every time I put a newer motor in a brass loco–and I’ve got tons of them–I mount it on a ‘pad’ of silicone. The stuff is flexible, it set-dries in about an hour–you can adjust it until then–and it isolates the motor perfectly. You can buy the stuff at a hardware store for about two dollars, and a little of it goes a long, LONG way. I swear by it.

Tom [:D]

5

[quote user=“NeO6874”]

My “kit” consists of:

  1. A multimete, or a DC powerpack in a bind

  2. CA

  3. .010" styrene strips (I found electrical tape to be too much of a pain to work with, and double sided tape would short the motor against the shell)

  4. xacto knife, with #11 blade

  5. #50 drill and 2-56 tap*

  6. stranded “jumper” wire for the motor brush that was fed from the frame

  7. Nylon 2-56 Screws (like from Kadee)

  8. 1/8" 2-56 screws (to hold the jumper wire to the frame*

*Only used if I can’t mount the jumper wire between the motor mount and the frame.

The method I used was this (note: these were steam locos, some steps may not be necessary):

  • Remove the motor from it’s mount

  • remove driver cover plate

  • remove drivers

  • File down front motor mount about .045" so wire worm gears can mesh*

  • File down rear mount about .015"

  • File down any other metal surfaces that may come in contact with motor about .015"

  • Above measurements are approximate, you really only need to take offenough material so that the gears mesh correctly

  • Glue .75"x.010"x.188" styrene strip to the REAR motor mount, and drill #50 holes as necessary to clear screws

  • glue short (about .25") .010" styrene to other exposed metal surfaces that may contact motor

  • cut a piece of wire about 4-6" long, place UNDER styrene strip*

  • place motor on top, use METAL screw(s) to tighten to frame (nylon screws strip out at this point)

  • replace drivers and driver cover plate

  • check gear mesh, if it’s good remove screw(s) and replace with nylon ones, tighten screws to get tighter mesh, or file down mounting point a bit more

  • Check for open circuit using multimeter or track power

  • (assuming track power method) If the motor doesn’t run, test that the jumper works by touching it to

6

A lot of ‘Made in Japan’ models with open-frame motors have one motor brush grounded to the motor frame with solder. Breaking that connection isolates the brush - which is really all you need. As long as both brushes are isolated from the frame of the loco, it doesn’t make any difference if the motor frame is ‘grounded.’

Chuck (modeling Central Japan in September, 1964)

7

I just roll on the floor laughing when I see dcc websites that state you can’t use open-frame Pittman motors as one brush is grounded.

What a load.

Insulate the silly thing with a piece of shrink-tube or just a chunk of wire insulation and solder the wire to the top of the brush arm.

If your motor is internally gounded, you do have to go through all the rigamarole to isolate the motor and then hope you don’t have a steel worm and brass wormgear.