RE: surging, motor

["David Roden" <roden ald net>]

Lots of great posts on this one.  This mailing list tends to be quiet 
much of the time, but when somebody has a problem everyone pulls out the 
stops.  I sure appreciate the help folks have provided me, and hope I can 
be of help to others.

Christopher Meier <Christopher Meier cwix com> wrote:

> Just to be clear;  
> occasionally, when at a complete start,
> when I advance the speed selector, the
> contactors clack on, but the motor doesn't
> budge or make a peep - nada nothing. 

Does the ammeter deflect upscale when you do this?  If not, you may have 
one or more open windings in the armature.  The winding might be just 
detatched from the commutator segment.  These are usually silver-soldered 
to withstand heat, so you can't just solder it back on with a 25-watt 
iron (alas).

It might also be just a cruddy com segment.  In any case you should not 
continue to run it.  If you have a motor shop you trust, have them do a 
test.  If you need to find a shop, call a couple local golf courses and 
ask the mechanic for the name of the shop that does motor work for him.

If the ammeter does deflect (especially if it deflects *a lot*), it might 
suggest some pretty serious friction in bearings or brushes/com.  
Friction would have to be *very* high; starting torque on these motors is 
pretty good.  This seems unlikely, since you're able to rotate the motor 
manually.

>  I turn the speed selector off, reach down, rotate the motor pully 
> slightly, then advance the speed selector, and it works fine again.
> Like a dead spot or something.

I have seen motors that wouldn't start in spite of drawing monstrous 
currents -- it was an open field connection.  However in this case a 
field problem doesn't seem so likely since you say it starts on its own 
after you have nudged the pulley.

I agree with the other posts; check the commutator, brushes, and armature 
windings.  Or pull it and take it to the shop.  Don't keep on running it, 
or it's apt to do more damage to itself.

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