RE: Ace Hardware grinder Sync conversion?

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Jim Mora" <jmora@xxxxxxxxxxx>

<snip>
<terry>
It will run hotter, but since your's is big, is
should still easily have enough power for grinding too...
<Jim>
*** not needed I would rather remove the other side to add power
I have run the 12" up to 3500 and it smoothes out nicely there.******

<Terry>
The motor will run at 3600.00... RPM so two
electrodes would do 120 BPS.  It will always sync
up the first time, every time.  It will be a big
high speed spinning thing, so balance and guards
are needed incase anything flies apart.

<Jim> **** Hmm if I run six will they all sync at 
the peak? I had not pondered that one. yes I?m on 
the lexan hunt? anybody ever form this around a 
barrel or something with heat?****

<Paste> <BW> (to another post) " A much better 
solution is to acquire the correct h.p. size 
non-synchronous motor (in your case 1,725r.p.m.) 
and modify it to become salient pole 1,800 r.p.m. 
synchronous. Be sure that you specify a capacitor 
start/induction run type of motor, and make sure 
it is a ball bearing type. Other types such as 
induction start/induction run or capacitor 
start/capacitor run are not suitable for this 
modification/application. It is best to have the 
modification to the armature done by a machinist 
in a machine shop; you need to make sure that the 
resultant modified armature is still dynamically 
balanced and that the angles of the flats (either 
two at 180 degrees or four at 90 degrees,) is very accurate.
Bill Wysock 
-------------------------------------------Tesla Technology Research

<Paste> <John> Jim,

I'm assuming this is a standard induction motor.
You can modify the motor to run synchronously, but it will
always start up in the same phase position.  I'm not sure
what you mean by making a few starts to get it on the AC
phase peak.  If you mean that you'll make a trial run, and
then rotate the rotor on it's shaft to a new position and try
it again, and keep repeating this until best sparks are obtained.
Then, yes, this will work.  But if you mean that you want to just
try flicking on the power switch to eventually hit the right phasing so
to speak, that won't work.  It's only the hysteretic motors that
are capable of phasing in on various phase positions at start up.
A modified motor will become a salient pole type and require
an actual mechanical or electrical phase shift.  Once it's phased
in though, then it can be left that way.

<Jim> ****John thanks for clarifying that. I?ll 
modify the base to make it adjustable. I?ll take 
the motor apart tomorrow and learn some more from the link you sent Terry****

Cheers,
John

Cheers,

Terry

<Jim>I love this place:-) Will I need a 
capacitive start as the esteemed Wysock suggests?

Thanks,