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Modifying Bühler replacement motor for LGB 2085D Mallet Locomotive

2K views 9 replies 6 participants last post by  Dan Pierce 
#1 · (Edited)
I inherited a lovely LGB set from my father, including a 2085D Mallet locomotive he purchased circa 1980. The rear motor on the locomotive died a couple years ago. (Taking it out and pumping high voltage and current through it causes it to turn fitfully, requiring far more DC than it ought to.)

I purchased a replacement motor and just went to swap it out…and it's not quite right. It's still a Bühler motor, and the body and shaft lengths match, but the motor does not fit correctly in the plastic; the "bumps" on the ends of the motor are 0.5mm and 1.1mm too long, and one of the bumps is just a little bit too wide (unsure if this is an issue). And, the metallic contacts are not in the same spots.

Photos and comparisons follow. My question is: have other people experienced this? Did I buy the wrong motor, or is 40 years too long to get a perfect replacement? I'm hoping I can file down the motor bumps to fit; have you done this? If necessary after I get it physically in place I may have to solder in a very short jumper wire to make the electrical connection.

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Thanks for any help or advice you can offer!

- Gavin Kistner
 
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#2 ·
The 2085 did have a motor that was shorter than the replacements available now. My friend has mounted the newer motor on his lathe and trimmed a small amount of metal off one end and these fit perfectly (another Jiro special). Others have trimmed the plastic in the engine to make the newer motors fit. I would replace both motors as there is years of difference in the making of these motors and I prefer a matched pair.
 
#4 · (Edited)
@Dan Pierce Great point about replacing both at once. Really good idea. And thanks for the confirmation that the “right” motor is the wrong size, even if it’s not what I wanted to hear. Will figure out how to safely but efficiently shave the extra metal.

@Exador If I had a lathe, it would seem a better choice than the bench grinder or angle grinder I’m considering… 😝
 
#7 ·
I inherited a lovely LGB set from my father, including a 2085D Mallet locomotive he purchased circa 1980. The rear motor on the locomotive died a couple years ago. (Taking it out and pumping high voltage and current through it causes it to turn fitfully, requiring far more DC than it ought to.)

I purchased a replacement motor and just went to swap it out…and it's not quite right. It's still a Bühler motor, and the body and shaft lengths match, but the motor does not fit correctly in the plastic; the "bumps" on the ends of the motor are 0.5mm and 1.1mm too long, and one of the bumps is just a little bit too wide (unsure if this is an issue). And, the metallic contacts are not in the same spots.

Photos and comparisons follow. My question is: have other people experienced this? Did I buy the wrong motor, or is 40 years too long to get a perfect replacement? I'm hoping I can file down the motor bumps to fit; have you done this? If necessary after I get it physically in place I may have to solder in a very short jumper wire to make the electrical connection.

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Thanks for any help or advice you can offer!

- Gavin Kistner
 
#8 ·
I ran into exact same issue on my 2085D a few years back. One motor was seizing and I ordered two figuring the second was not far behind. Upon arrival ran into fit problem. I elected to use my dremel tool to modify Loco chassis. It's been running great ever since. Good luck!
 
#10 ·
Note that it was Jiro that did my motors, he is a member in my RR club and lives only 40 miles from me. He let me know it is important to be careful on how much you trim the metal and as a result the motors after being trimmed do have a tight fit as he did not want to disturb the bushing/bearing.
 
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