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Re: SRSG motor anomoly
> Original Poster: "Mark Broker" <broker-at-uwplatt.edu>
>
Hi Mark,
The flats (which you grinded and/or filed) should be equal with the ungound
areas between the flats. Grinding more away will not help the torque. We loose
torque when we create a snyc motor. A 1/4 HP motor is on the low edge for a
motor choice for this pupose. However, depending on the actual spark loading
(physical) at the gap and frictional losses, this may work ok anyway. Try to
keep the frictional losses down to a minimum. A larger heavy disk w/ electrodes
is also going to load it. I would suggest keeping you electrodes down to a
minimum (120 bps) and check out how it holds snyc during actual running of your
coil. It may do ok. If not, try to minimize the frictional losses. Don't use a
belt drive as this adds a great deal of phsical loading. Stick to a direct
drive rotor.
Good luck,
Bart
BTW - my SRSG is 1/3 HP motor size, and I too am on the low edge. Best to use a
1/2 HP or bigger to keep torque up to par.
>
> 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.