Well I finally got it all squared away... After lots of frustration and staring at a dissasembled motor assembly with complete confusion I found a tiny tiny piece of metal flash or something that was lodge up in the top magnet of the motor. It would catch on something as the motor was spinning i guess. Anyhow, easy fix which is always was I like to find!
Don
I had an old Atlas/Kato RSD-4 that wouldn;t run - sometimes if you pushed it it would run bu if you stopped, it would never start up again. I took it apart and discovered that some of the glue used to attach the commutator segments had gotten on the surface of the commutator, effectively insulating one pole of the motor. I originally thought I was goign to find a loose or broken wire, hopegully where it was soldered to teh commutator so I could easily fix it - but it was even easier to scrape the excess glue off and clean up the commutator segments. Put it back together and it ran like a Kato should.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Springfield PA
I have an HO GP40-2 doing the exact same thing. I disassembled all the gearing, washed, cleaned and relubed everything... still doing it. My only guess left is that one of the gears has worked its way loose and has a little bit of play in it that is causing it to no longer be planar with the mating gears...
.... if thats not it then I am totally at a loss.
Dave Loman
My site: The Rusty Spike
"It's a penny for your thoughts, but you have to put your 2 cents in.... hey, someone's making a penny!"
I will have to check out the motor issue, it didnt run jerky though. Once it "unsnagged" it ran real smooth. If I stopped the loco it would bind up again, then take off and run smooth again. I may have already taken care of the decoder issue but the binding is still there. Its the fact that it runs smooth after it "unsnags" that now has me puzzled.
If the lights flicker while you're putting it on the track that would seem to indicate a pickup problem. On these N Scale locos it's so easy to get the pickups a little out of line. As for the humming and strange running, I have an SD7 that did the same thing. It turned out to be a slight bind on the motor. The motor was tilted slightly. I pushed it over so it was upright as it should be and it ran like it should. The jerky running sounds (again) like a pickup issue.
Dr. Frankendiesel aka Scott Running BearSpace Mouse for president!15 year veteran fire fighterCollector of Apple //e'sRunning Bear EnterprisesHistory Channel Club life member.beatus homo qui invenit sapientiam
I just got a brand new N scale Kato SD40-2 and spent some time programming it and lubing everything up properly and so on. Before I did all of this I put it on the track for a minute and it had power and was humming but wouldnt run, then it would take off like the gears were catching on something... Anyhow I took it apart and I can turn the gears with the driveshaft freely without it ever hanging up at all. So I oiled it up and put the trucks and the driveshaft back onto the frame, put everything back together properly.
Now I put it back on the tracks and all I get is the lights flicker when i rail it then absolutely nothing... If I take it off the rails then put it back on, same thing.... Im sort of lost here