RE: SRSG motor modification

["Colin Dancer" <CMD-at-datcon.co.uk> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

I'd second the suggestion to use a larger capacitors, but you need to be
careful not to go too far.  If you make the capacitor too big, you can end
up with the phase in the secondary winding nearer 180 degrees out of phase
rather than the 90 degrees intended.  I found that with a 20uF capacitor
(rather than the 4uF original) my motor ran raggedly at 1500 rather than
3000 rpm!

If you motor is close to but not quite locking it should be making a whining
sound with a 0.5s - 3s period (as it gets near to lock and then slips).

Kind of like,   wwwwwWWWWW.....wwwwwWWWW......wwwwWWWW....  :-) 

If that's the case, then it might be worth trying to get an lock using a
variac to boost the initial voltage.  I found only an extra 30V was required
to get my 1/4HP motor to lock with a 6"disc, and after lock I could reduce
the voltage back to 240V.  It's also worth trying for a lock without your
disc attached.  If it won't lock with no disc then it's never going work
when you add the extra drag of a rotor plus flying electrodes.

Regards,

Colin.

P.S. A number of the images on your website seem to be zero length files and
I wasn't able to load the picture of your motor.

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: 08 August 2000 18:41
To: tesla-at-pupman-dot-com
Subject: Re: SRSG motor modification


Original poster: FutureT-at-aol-dot-com 

In a message dated 8/7/00 4:47:35 PM Pacific Daylight Time, tesla-at-pupman-dot-com

writes:

> Original poster: "Garth van Sittert" <garth-at-mediasupplies.co.za> 
>  
>  Thanks for replying.
>  
>  The motor is 1/4 HP or 180W
>  2850 rpm 50Hz
>  
>  My armature measures: 4" long,  2" diameter.
>  
>  The 2 flats I have made are 1" wide.
>  
>  I have pictures of it at http://teslacoil.8k-dot-com/spark_gap.htm

Garth,

I tried looking at your webpage, but the pictures didn't load for
some reason.  In any case, I'm thinking that maybe you need
to use a larger capacitor than 6uF,  you could try larger ones
such as 10uF or 20uF, and see it that makes it lock up OK.
The flats should be plenty deep enough the way they are now,
by the way.

Cheers,
John Freau