Re: Found: Sync Motors??

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 2/17/01 4:15:05 PM Eastern Standard Time, tesla-at-pupman-dot-com 
writes:

> Original poster: "G by way of Terry Fritz <twftesla-at-uswest-dot-net>" <nieporgo-at-
> email.uc.edu>
>  
>  Hi John, List,
>  
>  I double-checked and it isn't marked HYST (like the first 200 motors 
>  I found were!!). It also says 1/35 hp. Is this high enough to spin a 
>  Lexan rotor with a modest amount of electrodes? I have seen many 
>  designs with only 4. Thank you for your help, this is my first 
>  attempt to improve efficiency with a RSG.
>  
>  Greg

Greg,

I use a 1/50th HP sync motor on my TT-42 TC.  Mine is 1800
rpm, and spins a 5.25" dia x 1/4" thick phenolic rotor with 4
spinning electrodes made from nuts and steel bolts.   I run
at 120 bps.  Some motors will be more powerful than others 
though, for the same ratings.  If you motor comes with a start 
or run cap, that helps too.

You can see my motor and sync gap at:

   http://hometown.aol-dot-com/futuret/page3.html

Generally, folks run a sync rotary at either 120 or 240 bps.
I prefer 120 bps because it's always been more efficient in
my work.  Sync rotaries can be used on any type of coil,
but are especially helpful on NST powered TC's.  Non-sync
rotaries are mostly used on MOT, PT, or Pig coils, because
they can destroy NST's.  Some folks have successfully
used non-sync rotaries with NST's though, but protective
NST networks are a must.

If you buy the motor, you can test it to verify that it is not
HYST.  Just tape a 3" dia. cardboard rotor to the motor and
draw a heavy black or white line across the disc.  Run the
motor in a room lighted with fluorescent light.  You will see
a locked pattern on the rotor when the motor is locked.  If
you unplug the motor, you'll see the pattern rotating and
changing as the motor slows down.  It may take awhile to
learn to see the patterns.  Some folks have trouble seeing
it at first.  (or you can build Terry's stobe light, which makes
the pattern easy to see.)    If the motor is a HYST motor, it
will lock in a different postition every time.  But it it's a 
desirable salient pole type, it will lock at the exact same
position (angle) every time.

John Freau