Re: SRSG motor anomoly

To: tesla-at-pupman-dot-com
Subject: Re: SRSG motor anomoly
From: "Bunnykiller" <bigfoo39-at-telocity-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Wed, 22 Mar 2000 07:28:36 -0700
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

Tesla List wrote:
> 
> Original Poster: "Mark Broker" <broker-at-uwplatt.edu>
> 
> Hey,
> 
> I finished machining 4 flats into the armature of a 1725 RPM 1/4 HP (or
> something close) motor recently.  Today, I attached my G-LE rotor (no
> electrodes yet :-(  )  to the motor and fired it up.  Ran pretty smooth
> after balancing.  I grabbed an old stroboscope and clocked it at 1800RPM!
> I was happy, despite there being no way with this scope to test for rotor
> position vs. the AC cycle.
> 
> Then, I applied a little load to the rotor by gently pressing on it with my
> hand.  The rotor position rotated about 10 degrees, then a full 90 degrees
> (to the next pole).  It took surprisingly little pressure to cause this.  I
> was wondering if I need to grind a little more off the armature?  I
> machined 4 flats .675" across, which is the distance between the two "dead"
> poles in the winding.  That is according to the directions I found on
> Terry's site.  Is it possible that the motor is crap?  It was replaced in a
> furnace.
> 
> Thanks
> 
> Mark B.



Hi mark ....


what HP is the motor rated for ? and what is the diameter of the rotor
of the motor? I also cut flats into a 1/5 hp motor for "synchronizing"
but i ended up cutting the flats to .89" wide.  the rotor dia was 3.25 "
and it takes a bit of drag to cause the shift to occur. 

you may need to cut a bit wider flat on the rotor to help maintain a
locked position....


Scot D