9V Motor jittering on straights?

[Rail Co]

Hi, I have probably a 20-25 year old motor that only on the straights jitters/loses connections and looks to be slightly bouncing. The track is clean because other motors work flawlessly on it. I am wondering if I need to take it apart or if something could be warped. I'd rather not have to buy another $50-$80 motor for my metroliner if I don't have to.

Thanks

-RailCo

[tnmears]

I found that sometimes it just takes running the motor for a time and it sometimes sorts itself out. This happens especially after not running for a period of time.

[Kintobor]

Could be dirty wheels. Try taking a paper towel piece and placing it on the track. Put the motor on the track with one wheel on the paper towel and run the motor, holding onto it. If you see black streaks on the paper towel, you've got dirty wheels. Do this with all the wheels and the motor should work again.

[legoman666]

Contacts inside the motor could be broken.

[dr_spock]

If it is straight only, it could be the pickups are making intermittent contact. You could have broken contacts or they don't have enough spring tension against the wheels. In the curves the track would force the wheels against the pickups making constant contact.

[pirzyk]

Is the jittering constant or follow a repeated cycle? I have seen it with PF motors as well under a constant heavy load (i.e. really long trains). It would do a 2 cycle jitter, clear up for a second and then another 2 cycle jitter. If I reduced the load, it would not exhibit the jitter. In a dual head setup, only 1 engine would jitter.

You may want to swap motors to see if it is the train itself or the motor. Also does it jitter with just running the engine (i.e. no cars)?

Edited July 11, 2016 by pirzyk

[Rail Co]

Okay so it was a mix of dirty wheels and dirty track actually. I used a paper towel on the wheels and on the track and they both came up black so when I ran it again it ran smoothly. I also brought out a third motor and it did the same thing so I think one of my motors just is in really good condition and it didn't mind the little grime on the track. Thank you for all your help!

Also out of curiosity what is the best way to open a 9V motor?

Thanks!

-RailCo

[mjotrainbrain]

If you take an X-acto knife and cut off all the little tabs on the bottom the case can open. You can still reassemble it without gluing and it will actually stay assembled fairly well, but not as well as with those clips intact. There is plenty of stuff inside that could need cleaning, just be careful not to bend the thin metal pieces on the sides!