Large Scale Central

Help me diagnose a motor problem?

General Discussion
#1

Dumb newbie questions. I know very little about DC motors, and have never taken one apart.

I have an old LGB 0-4-0 steamer in American profile–model #2117 D

It ran marginally well but sometimes needed a nudge to start. Then it fell into a pond–kids!–and after that ran poorly and then not at all. I finally took it apart today–power pickup was fine, but when I hooked the motor directly to the transformer I got nothing. The worm gear and driveshaft turn freely. It’s a Buhler motor.

So I sprayed a whole bunch of contact cleaner in there. Now it runs, but it still needs a nudge to start–just a little tiny twist of the worm gear. And it seems to run a bit unevenly–if the motor is rotated, it seems to hesitate a bit.

So what am I looking at–internal corrosion? Maybe some of the contact cleaner hasn’t evaporated yet? Does it need to be lubed, and if so how? It can obviously be taken apart, but I’m not sure at all that I want to go there. Maybe it’s just shot? Any suggestions?

I have some other LGB 0-4-0s–two “stainz” engines–I could cannibalize.

#2

Make sure that the drive gear is not binding and has sufficient lube. That is the usual suspect. From what you describe, there might be some corrosion in the motor bearings. As to how to address that, I will defer to someone more experienced than I.

#3
mike omalley said:
I have some other LGB 0-4-0s--two "stainz" engines--I could cannibalize.
They should have the same motor. If you do scrap one of the Stainz, I would be interested in buying the remainder.

Jack

#4

Thanks all. I just ran it some more–the motor completely removed from the drive block–and it runs better in some positions than others–that is, as I rotate it, it runs more roughly then smoothly. An it seems to run better with the polarity going one way. When I hit the “direction” switch on the transformer, it runs more smoothly in one direction

I suspect it’s on its deathbed

Jack the stainz I would cannibalize has seen HEAVY use at the hands of kids

#5

Mike,

Sounds like a brushes and commutator problem.

#6

Is it worth it to try to take the motor apart? Is there likely to be anything I can fix?

#7
mike omalley said:
Jack the stainz I would cannibalize has seen HEAVY use at the hands of kids
Mike, I'm looking for some of the steam pipes, tank filler (on the left side). I would still be interested.

Jack

#8

Mike,
you need a replacement motor. Any of the small four wheel motor blocks would be suitable as a donor. This motor sounds like it has has had a lot of use. The swim in the pond did not harm it. The motor is worn out (commutator and brushes). Commutator cleaning/refurbishing and brush replacement is not really an ‘inservice’ adjustment.

#9

Sounds like it could have a dead winding, if you were real ambtious you could use an ohmmeter to check. Check the pairs of commutator segments that the brushes touch… you could try measuring the resistance of the motor while you manually turn it from segment to segment. I’ll bet one of them is open.

Regards, Greg