Re: srsg confimation of findings

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

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi Ben,

At 12:43 PM 4/24/2002 -0700, you wrote:
>Hi colin (Terry), 
>  I just finished building an SRSG, and mine starts to
>'hunt' at about 75-80 votls.. (that's what the variac
>says.. I haven't measured it yet).. 

That is perfect!

>I have a few questions
>though.. My rotor is mounted with a small aluminum hub,
>which is slightly bent.. I'm guessing that the motor was
>dropped on the shaft end and that's what bent the hub..
>when I run the motor, the rotor wobbles a little and sends
>the whoe thing dancing across the table.. I've already
>checked for balance, and that appears to be ok.. will this
>be a problem as far as jitter and gap spacing goes? 

Motors almost always need to be bolted down when running.  They like to
travel around if not bolted to like a rock.  The faster 3000 RPM motors are
more sensitive to imbalance and such.  I think once the motor is bolted
down it will be fine.  It is very important to be sure the rotor will not
fly off and to shield it somehow incase it "explodes" so chunks don't go
flying far.

>Is
>there any way to correct this without access to a lathe?

Balance is about all you can do.  You may try using a marker to find the
bend direction and try bending it back, but that is sort of risky.  See how
big of a problem it is once the motor is bolted down before worrying too much.

>Also, I was gonna build a phase shifter for it with a
>variac, but the motor has a run cap already on it.. Are
>there any design constraints that I have to watch out for
>with this kind of motor? Thanks for any help.. 

A John Freau question ;-)

Cheers,
	
	Terry


>
>Coiling In Pittsburgh
>Ben McMillen
>
>--- Tesla list <tesla-at-pupman-dot-com> wrote:
>> Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
>> 
>> Hi Colin,
>> 
>> That sounds perfectly right.  If you want to be
>> scientific, you may want to
>> check to voltage when sync is lost.  I think people say
>> it should be less than
>> 100 VAC (assuming 120VAC is normal for your motor) to
>> give a reasonable safety
>> margin.
>> 
>> Cheers,
>> 
>>         Terry
>> 
>> 
>> At 02:32 PM 4/24/2002 +0100, you wrote: 
>> >
>> > hi all
>> >         thanks for the help with my srsg i think it is
>> syncronous as when i
>> > watch it the electrodes appear still my the posts under
>> flourescent light
>> > they do not slowly move around and when i drop the
>> voltage it hunts
>> > could you people confirm weatgher this sounds right?
>> >  
>> >  
>> > many thanks
>> > colin heath        
>> 
>>