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Discussion Starter #1
My question actually goes along with several pre/postwar spur gear type locomotive mechanisms. The armature shaft hole in the fiber brush plates often wear out due to years of minimal maintenance and lots of running. I've got a 2065 Hudson on the workbench that I'm working on and it has this problem. I can lightly grease the shaft of the armature and it eliminates the resulting squealing noise for a short time, but in the end the brush plate just needs replacing. Jeff Kane supplied me with some modern versions of the brush plate that have a bushing installed (much better design IMO) but he mentioned that they don't fit everything. Everything lines up and the fit around the armature shaft is snug, but not condemnable. When it's all assembled however, things get rather tight. I believe it's due to the shoulder on the bushing that protrudes out the back side. The thickness of that shoulder allows it to rub on the armature and likely causes my problem. I believe the MPC motors these were designed for have cutouts on the armature in this area, so it's not much of a problem. The postwar armature actually has a built in thrust washer to space it out from the brush plate. I tried shimming the brush plate out slightly with some thin cereal box cardboard which does help, but only without the shell in place. With the shims in place the brush holders just barely touch the shell and cause a short. I'm going to disassemble it again tomorrow to see if I can eliminate the short.

Now to the question. Is there an easy way to modify these modern parts to work with the postwar armature? Is there a source for NOS originals? I may have a good one on a junk box locomotive, but I hate to scavenge from them as I intend to put them back in service one day... :rolleyes: I also hate to take a chance on an eBay part as most of the ones available seem to be used and possibly have the same issue.
 

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Yard Master & Research
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You could update yours with a rivet. The armature shafts are a little long maybe you could layer something and glue in place, I am sure of the 2065 piece if it is original or used in other models.
 

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Discussion Starter #3
Thanks! I've contemplated doing something like that. A brass grommet with the correct interior diameter might do the trick without sticking out so far from the brush plate. We often make repairs at work on larger, but similar things by drilling oversized and installing a pressed in bushing. I wish I would have thought to bring my wire size drill bits home from work before we got locked out. The hole size seems to be just a hair smaller than 1/8".

I may try filing down the shoulder a bit on the MPC part to see if they fit any better. I think it fit the purpose of that built in thrust washer that the postwar armatures seem to have, so it probably doesn't need to be as thick as it is.

I found a couple of originals on eBay that were a reasonable enough price to take the chance so they should be here later this week. The 2065 I'm working on belongs to somebody else, but I just noticed that my recently acquired one seems to be having the same issue. I probably have at least a half a dozen of these chassis under various locomotives so it's a problem I should probably learn how to deal with sooner than later :D
 

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I turn my own bearings but a grommet should work. I would try and find one slightly undersize and drill to fit if you have number drills. Its too far off for a common fractional drill to work.

Pete
 

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Discussion Starter #5
As an experiment I filed down the shoulder on one of the MPC parts I got from Jeff Kane this morning and it seems to have done the trick. The locomotive runs great with no drag on the mechanism and best of all... no squealing. I plan to give it some more break in time to see if anything changes, but so far so good. My shorting issue when I shimmed the plate out was due to the modern parts having solder blobs on the other end of the brush springs where they meet the brush holders. The postwar units just rely on spring tension to make proper contact. I filed the solder down a bit to be safe and that seems to have solved that.

If it comes to making a bushing for the original parts, I'll likely wait until I'm back to work and turn out a couple on the lathe when I'm on my lunch break. Unfortunately I only have a cheap set of fractional drills here at home for around the house stuff. The more I've been thinking, a grommet sounds ok in theory, but I'm not sure how it'd be as a long term solution and I'm not sure I could end up with the proper ID with something like that. I could drill it out to whatever size I want, but I'd worry that the wall thickness would be on the thin side with a solution like that. Thanks for your insight.
 

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If you have a lathe then its pretty straight forward assuming you have drill that is close. It seems Lionel used an oddball shaft size on their armatures like .090" instead of the more common .093.

Pete
 

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Discussion Starter #7
Yes, I've probably made more difficult parts before. Unfortunately I decided I didn't need to bring anything home for the quarantine period so all of my precision measuring tools and drills are still locked in my toolbox and unaccessible for a couple weeks... That'll probably be an experiment for a later date now that I seem to have a solution in place at the moment.
 
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