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Re: mod of sync motor (trying to modify)



In a message dated 3/28/00 3:39:01 AM Pacific Standard Time, tesla-at-pupman-dot-com 
writes:

> at's just a little below a 50-50 ratio, 
>  just like you suggested :) The motor ran *much* more smoothly. 
>  I attached a fan to the shaft and put it under a floressent lamp. 
>  I could see a "cross" pattern in the spinning blades, so I "think" 
>  I've succeded here.

Yes, if the cross pattern does not rotate under fluorescent light,
then it is good,  as you lower the voltage with a variac, you'll hear
the motor fall out of lock and begine hunting sounds as you raise
teh variac gradually, then when it locks fully is will be very steady and
smooth.
>  
>  Feeling lucky, I moved on to the 1/3 HP, 3450RPM motor. Still working
>  under the dead pole method, I cut .750" flats on it's 2" rotor. 
>  (BTW, what porportion of cut to uncut do you use on a 3450RPM motor?)
>  I had a starting cap that came with this motor, and when I powered it 
>  up, it spun right up and ran very smoothly. I didn't have anything to 
>  put on the shaft to help in telling if we're locked or not. I'll be 
>  making the strobe described in Terry's STROBE.ZIP file to help verify 
>  sync.

I'm not as sure about the best amount of cut for a 3600 rpm motor, because
i"ve only modified one of those.  My rotor was 1 7/8" diameter.  I made the
cut 1 1/16" wide, but I think maybe a little narrower would have been good
too.  In any case, the motor was very powerful when done.

Cheers,
John Freau
>  
>  Well, more experimenting during lunch tomorrow :)
>  Paul