Cleaning gears

[Curtis Kyger]

I have four locomotives which I believe are all suffering from the same problem. They are N-Scale Atlas ESU equipped: 2 C420’s and 2 GP30/35.
My purpose in posting is to see whether yew awl will share your methods of remedy, or whether you think I’m off base in my analysis.  [Speaking of remedies, queue the picture of a bottle of Bourbon or Scotch here].
The units ran flawlessly for several years but have stopped mid route with sound still functioning but motors no longer turning -- and no, it's not a Drive Hold issue.  Initially I thought the motor tabs may no longer be in contact with the electrical pads on the bottom of the ESU boards.  However, upon inspection I determined that is not the issue--the motor just no longer desires to spin. I can flick the motor with a wooden toothpick, and it will resume running.  My analysis based on observation is that there is so a bunch of excessive grease on the worm gears, bearings and truck gearing (which has not aged gracefully) and that rather than continuing to function as a lubricant, it has thickened to the point of becoming resistant to movement.
Assuming my observation is correct, how do you guys clean old lubricants from your locomotives?  What products, tools and methods have you found optimal to do the job?

[peteski]

If these experienced long time usage then it is possible that the motor brushes or even the commutator wore out. Or there is a broken wire in one of the windings.
Some older locos has a light cream colored grease which could harden up and get sticky. If there was hardened grease then the model, especially when cold after sitting overnight, I think it would need much higher starting speed step (to overcome the sticky lube). SInce the motor starts running normally after being flicked that to me also indicates that the problem not due to thickened lubrication.

Since you are using a toothpick to move the motor's rotor, you can likely tell if there is any extra resistance while turning it. If you have similar loco which works ok, you could try comparing the turning resistance in both models.

There is also a possibility of a strange decoder malfunction. I seem to vaguely recall that @Dwight in Toronto had a strange problem similar to this. Sorry to get you involved again Dwight, but I think you did some serious troubleshooting (and I don't recall the outcome).

When I need to tuneup and clean locomotive mechanism I fully take it apart (including full disassembly of the trucks) and clean everything with solvent in my ultrasonic cleaner. Then I assemble and lube everything.

[Dwight in Toronto]

Peter - good memory!

Long story short … I had both a Kato and an Atlas ESU sound-equipped loco act up in ways similar to OP’s description.  In both cases, I stripped the mechanisms down to bare components, cleaned everything (including removing motor brushes and cleaning commutators). 

After rebuild, everything would run fine on DC.  Upon reinstalling decoders, DCC/sound would be good, sometimes for days, other times for a few minutes, and then the “died on the tracks” frustration would reoccur.  I seem to remember sound and lights remaining functional, but no motor action whatsoever.  Bypass decoder - good DC operation; reconnect decoder - good DCC/sound for indeterminate time.

In both cases, I think I ended up installing new motors and decoders.  I’ll try to review those threads and report back. 

[Dwight in Toronto]

As promised, I found the thread from two years ago regarding Atlas motor/decoder troubleshooting:

https://www.therailwire.net/forum/index.php?topic=57864.msg796834#msg796834


Damn, that was a head-scratcher!

[Dupesy]

I also have 2 of the newer Atlas mechanisms (both of the GP38/40 variety) that will randomly stop running.  One has a factory-installed LokSound decoder, the other a LokPilot I installed.  I'm almost certain (especially after reading the linked thread) they have faulty motors.  Both have only a couple hours of run time.

[mecgp7]

Do not forget to clean the phospor-bronze cups that hold the axle points.Over time they gunk up and you will experience what you have described. I have had brand new locos suffer from this due to excessive lube. Loco may not start, but will with a push or a flick of the motor. It will gain speed slowly, but never reach a top speed.

[bbunge]

My go to for cleaning grease and over lube from mechs is CRC electric Parts spray.  I used to do tests to see if it damages plastic parts, but tend to skip that these days since I've never experienced a problem.  It will take off some paint though. 

While I've decanted it into small containers, I'll usually take a stripped down chassis and truck assembly and spray it down over a container to catch the drippings.  It takes the grease off, but also cleans any electrical contacts. 

A second vote for checking the axle cups. 

Bob

[peteski]

I'm curious why check axle cups if simply giving the motor's rotor a little push with a toothpick makes the model run again.

Chris mentioned "not a Drive Hold issue" which seems to imply that the decoder is still receiving track power, the sound is playing, and the lights are working with only the motor stalled.  Is that correct Chris?  If that is the case, then the power path from the track to the decoder *IS NOT* the issue.

[Curtis Kyger]

That is correct Peteski.

[randgust]

Bachmann is notorious for drowing units in lube, some others, but I've never seen an Atlas seize up due to that.   But yeah, the end-axle pickups, in Kato, and Atlas, have the potential to oxidize and build up an arc carbon layer over time.    Nudging it or holding it to get it restarted spins the points enough to wear through a layer temporarily in the cups.   Just like wheel tread oxidation on a Life-Like.

Before they started soldering truck wires to everything, it was fairly easy to pop apart a truck, pop the pickups out, and either manually or ultrasonically clean them.   Now it's more complicated.   Most of the DCC boards I've seen are incorporating plugs now on the basic connections, helps, sorta.

And after you get the stuff out, I'm a firm believer in Atlas Conductalube.   It's magic.  The 'before and after' is actually worth it, particularly on Kato drives.

There's times when I think it would be worthwhile to dummy up something out of styrene or RP or something with some strip brass or wires on it to simply temporarily hotwire a mechanism back to DC, eliminating the decoder entirely, to research the problem.  I've gotten that frustrated with BLI, and also my Trix Decapod, to develop a hotwire system to snap in an instant 'convert to DC' option when I'm suspect it's motors, gearing, pickup, etc.

I've seen other things go haywire, especially with 'modern' tiny-teeth gears, with random debris getting caught in there and randomly siezing a mechanism up.  Scenic turf, metal particles, etc. 
I have a micro-gear motor with a 3v motor on it for an animation, and the darn thing kept randomly seizing up.  Took a magnifying glass to spot it, one tiny piece of scenic grit, in one micro spur gear tooth, that would travel around.   Couldn't believe the size, and the random behavior, but picking it out with a piece of .008 wire did it.

[peteski]

Bachmann is notorious for drowing units in lube, some others, but I've never seen an Atlas seize up due to that.   But yeah, the end-axle pickups, in Kato, and Atlas, have the potential to oxidize and build up an arc carbon layer over time.    Nudging it or holding it to get it restarted spins the points enough to wear through a layer temporarily in the cups.   Just like wheel tread oxidation on a Life-Like.

Sure Randy, but in this case electric pickup between track and decoder is not the problem.

[McKeen]

My go to for cleaning grease and over lube from mechs is CRC electric Parts spray.  I used to do tests to see if it damages plastic parts, but tend to skip that these days since I've never experienced a problem.  It will take off some paint though. 

While I've decanted it into small containers, I'll usually take a stripped down chassis and truck assembly and spray it down over a container to catch the drippings.  It takes the grease off, but also cleans any electrical contacts. 

A second vote for checking the axle cups. 

Bob

I do exactly as Bob does also saving the decanted fluid after straining through a coffee filter and storing in a small glass jar.
When axle cups ae extremely tarnished, I use a Tamiya triangular (conical) cotton swab with some Brasso.
It makes those pick-up cups shine like new money.