RE: sync motor question

["Lau, Gary" <Gary.Lau-at-compaq-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Hi Mark:

I think Terry covered the sync conversion suitability, but I wanted to raise
a couple more issues.  You mentioned that the shaft had a 5" pulley for a
belt on it.  I'm not sure if you were planning on mounting the disk directly
to the pulley, or using a belt with another pulley on the disk.  There may
be problems with either case.

If you mount the disk directly to the pulley, the 5" size is kind of on the
large size.  You will want at least 2" clearance on the disk from the
(grounded) pulley to the electrodes, so the disk will need to be at least
10" diameter.  You may want to take a look at Terry's technique of using a
drill chuck to mount a disk to a shaft of any diameter.

If you were planning on using a belt, unless the pulleys and belt had teeth,
the RPM ratio between the motor and disk will not be precisely 1:1.  Even if
its 1.00001:1, the phase of the disk will slowly shift relative to the
motor's shaft and the AC mains.

Regards, Gary Lau
Waltham, MA USA

		Original poster: "Metlicka Marc" <mystuffs-at-orwell-dot-net> 

		hello all,	
		i have a question for those in the know about sync motors. i
recently
		got a blower assembly, it has a robbin myers ac motor on it,
on the
		label it reads 115v 60htz 3350rpm\ 115v 50hz 2725rpm, 1/3
hp.
		my question is, since the speed is labeled different for the
two
		frequencies, could this be a synchronous motor?
		it already has a very nice 5" flat belt pulley that bolts to
a hub on
		the shaft, and very smooth bearings.
		i am hoping this can be a good find for a srsg?
		thank you all in advance,  marc metlicka