# Pump motor problems



## major (Apr 4, 2008)

DavidDymaxion said:


> The cross piece on the end is plastic. Could this be flexing enough the armature is hitting?


That is just a shipping bracket. The motor is intended to use the end bracket and bearing from the mating pump, much like the golf cart motor uses the axle housing for the bracket and bearing.


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## DavidDymaxion (Dec 1, 2008)

Many thanks. It does have a huge bearing in the plastic bracket. I'll make a metal end bell for it.

Do you think the shaft would be accurately centered wrt the motor case? If yes that would make machining the endcap more simple.

If I can get it to work, the pump motor is nice as it was cheap (cheaper than the last car starter I bought), and a shunt motor. As a shunt motor it'll spin a constant speed, great for a lawn tractor that had a constant speed gas motor, and no need for a controller. 


major said:


> That is just a shipping bracket. The motor is intended to use the end bracket and bearing from the mating pump, much like the golf cart motor uses the axle housing for the bracket and bearing.


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## major (Apr 4, 2008)

DavidDymaxion said:


> It does have a huge bearing in the plastic bracket.


Hmmm. Maybe it shares the bearing with the pump. But no-way would use that flimsy plastic bracket. 


> Do you think the shaft would be accurately centered wrt the motor case?


I wouldn't count on it.



> As a shunt motor it'll spin a constant speed, great for a lawn tractor that had a constant speed gas motor, and no need for a controller.


What makes you think it is shunt wound?


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## DavidDymaxion (Dec 1, 2008)

Thanks again. One of the sellers referred to it as a shunt motor, the spec sheet says "Field 12V, armature 12V", and 2800 rpm seems slow for a series motor this small. I haven't been able to test it it is a shunt motor for myself yet, though.


major said:


> Hmmm. Maybe it shares the bearing with the pump. But no-way would use that flimsy plastic bracket.
> 
> I wouldn't count on it.
> 
> What makes you think it is shunt wound?


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