Re: sync motor RPM ???
---------- Forwarded message ----------
Date: Tue, 21 Oct 1997 18:56:53 +1000
From: Peter Electric <elekessy-at-macquarie.matra-dot-com.au>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: sync motor RPM ???
I have modified a few of these motors now and none of them could be
checked by just using a flouro light on the shaft. The flouro's just
don't give a sharp pulse of light like strobes do. Get a plywood disk
(at least 4" in Dia) and draw two large black 90 deg quadrants with a
whiteboard marker (opposite each other) spin this up and you should see
staionary dark patches. As you turn it off you should be able to see
them start moving as it goes out of sync.
Hope this helps,
Tesla List wrote:
> ---------- Forwarded message ----------
> Date: Mon, 20 Oct 1997 18:17:55 -0700 (PDT)
> From: gweaver <gweaver-at-earthlink-dot-net>
> To: Tesla-at-pupman-dot-com
> Subject: sync motor RPM ???
> I made a sync motor today using a 1/4 HP electric motor. I cut 4
> flats on
> the motor rotor. The flats are all equal. The flats are at 90, 180,
> and 360 deg. The space between the flats are equal to the flats in
> width. I
> did this in the milling machine so its within a few thousands. The
> motor is
> 1725 RPM and has 4 start windings and 4 run windings. I turned it on
> let it run for 5 hours and it did not over heat. I checked it to see
> if it
> was running 1800 RPM's but I don't think it is. Fluorscient lights
> blink at 60 HZ and make the shaft appear to be stopped but it
> doesn't. I
> connected a neon light in parallel with the motor and use the light in
> dark to see if the shaft appeared to be stopped but it isn't. I put a
> on the neon so it would blink at 60 Hz and tried again and the shaft
> does not appear to be stopped. The shaft keyway can not be seen even
> if I
> move the neon light all the way around the shaft 360 degrees in the
> Any ideas?
> Gary Weaver