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Re: mod of sync motor (trying to modify)
Hi John!
Original Poster: FutureT-at-aol-dot-com
>
> usually the cut and uncut areas must be about equal, with the cut
> areas a little smaller maybe than the uncut areas, so if you have
> not gone beyond "equal" for the cut and uncut, then the motor is
> still OK.
Well *that* being the case, the 1/40th HP motor is now a nice paper-
weight. But, the little motor was only suppose to be a test case to
learn how to cut the flats anyway. I moved on to the 1/4 HP, 1725RPM
and the 1/3 HP, 3450RPM motors this afternoon.
The rotor on the 1/4 HP motor was 2" in diameter. I hadn't read your
post about cut and uncut being equal, so I started by cutting four
.520" flats. I put the motor back together and fired it up. The motor
seemed to pulsate as it was running, and finially smoothed out. I
took it apart again and trimed down a bit more until I had .750"
flats. (coincidentally, that'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.
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.
Well, more experimenting during lunch tomorrow :)
Paul