Re: I got a new motor! (SRSG HELP)

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

Original poster: "BunnyKiller by way of Terry Fritz <twftesla-at-uswest-dot-net>" <bigfoo39-at-telocity-dot-com>

Tesla list wrote:

> Original poster: "Andrew W by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<fateagk-at-home-dot-com>
>
> Hello everybody,
>
> I picked up a nearly brand new 1/3 hp motor today at a hamfest for $10. The
> label says 1725 rpm. There is no motor start capacitor that I can tell.
If this
> is not a capacitor start motor, but an induction start, will this still be
> usable as a SRSG? Also, just so I am sure my information is correct, do I
need
> 4 flats at 90 degrees to each other for synch operation? How do I
determine how
> much material to take off for each flat?
>
> Thanks,
> Andrew

hi Andrew...

this is from a previous post   hope it helps



> the width of the cut can depend upon 2 items
> the design of the case windings ...   dead pole or non dead pole
> ( if there is a point at which the windings are formed away from each
other this can be
> considered
> a dead pole area. , and then there is the true dead pole area , this is
in which there is a
> lack
> of windings in the core slot.)
>
> as far as cutting the rotors a formula was derived for simplicity
>
> a 38 degree arc ( for non dead pole windings) is suggested
>
> a 40 degree arc for true dead pole windings
>
> the 38 degree arc formula is...
> this will determine the WIDTH of the cut made upon the rotor
>
> 2 X (sqrt(R^2 - (R X .9455)^2))
> (( the .9455 = the cosine of 1/2 of the arc angle))
>
> the 40 degree is ...
>
> 2 X (sqrt(R^2 - (R X .9397)^2))
>
> for a 38 degree cut...
> example    we have a rotor of 3" diam.    therefore the R =1.5"
>
> R squared = 2.25        (R X .9455) squared  = 2.011
>
> 2.25 - 2.011 =  .23385
>
> the square root of  .2385 = .4884
>
> this multiplied by 2 = .9768" width of the cut made to the rotor
>
> hope this helps ...
>
> Scot D