My Proto 2000 SD40 has always been running perfectly, drawing 0.2 Amp. Suddenly while pulling a short train it slowed down to a crawl and went from 0.25 to 0.8 Amp.I took the locomotive apart and checked all the moving parts, they were clean and well oiled wkith Nano oil. I then took out the motor and ran it unloaded, it still took 0.8 Amp and got quite hot after a short running time. My conclusion was that the cause of the problem must be inside the motor. My question is has anyone ever had the same problem with a Proto 2000 motor and is there a remedy apart from buying a new motor.
Thanks for any suggestion
Hans
Hans,
It's quite possible that the inner/outer armature shaft bearings/bushings need to be oiled. With dry bushings it takes more current to get the motor to turnn, thus creating heat from the friction of the dry bushings. Sometimes that binding is associated with a slight squeal, but not always. I would try that first before giving up on it. Some motors they are hard to get at, but can be done. LaBelle makes an oil container with a small long brass nozzle that is perfect for that #102 oil. I heard over the past yr. about not so good news about Nano oil, but I won't get into that. There was a thread here sometime ago about it, by Hon30critter....but I don't believe that is Your problem. Just try lubing the shaft...hopefully that will solve Your problem. Could also be brushes worn-out/tension etc. Try the shaft first.
Take Care!
Frank
I'm also interested in the answers you get as I have an MDC 2-6-2 loco in which I installed a NWSL can motor that is also having similar problems. This loco (as well as another MDC 2-6-2 twin) used to run quite smoothly around my layout at DCC speed step 20 of 128 for hours. One day, I attempted to run this loco but had to set the throttle around speed step 80 of 128 just to get it to run at the speed it used to run at speed step 20. Nothing seems to be binding and the loco still runs smoothly. It just requires a lot more power now. It's twin still motors around happily at speed step 20. Is the can motor failing?
Hornblower
zstripeI heard over the past yr. about not so good news about Nano oil, but I won't get into that. There was a thread here sometime ago about it, by Hon30critter....but I don't believe that is Your problem.
Hi Hans:
The thread about Nano Oil that Frank refers to was about Nano Oil not being compatible with ABS plastics. Apparently it causes ABS to break down. As Frank says, that is not likely your problem.
Which grade of Nano Oil did you use on your motor bearings? If you used #5, that may be your problem. #5 is a penetrating oil designed to free seized components. Eventually it will evaporate leaving no lubrication in the bearing. I may be out to lunch here since you said that things seemed to be "well lubrcated" with Nano Oil. If you used #5 there probably wouldn't be any visual trace of it. In any case, I would suggest using #10 for motor bearings.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
No, I have not had this problem with a Proto motor.
The general case:
This motor drawing .8A unloaded and "in free air" (out of the locomotive) is bad. Obviously.
Yes, lubrication is the first thing to check. Does adding lubricant solve the problem?
Next would be the brushes. One or both may need attention/replacement. Does attending to this solve the problem?
Next (which might be done while attending to the above), examine the commutator for damage.
That leaves damaged coil windings. This is almost impossible to repair. Replace motor.
With motors from the olden days (think Pittman), all of the above steps were quite simple. In fact, you could examine the brushes and commutator without disassembly. Motors today are not so accessible. Some of the above steps might by way more trouble than they're worth. And then there's the problem of obtaining replacement brushes.
So the short, practical answer is that if lubrication doesn't solve the rather incredible current draw problem, get a new motor.
Ed