Re: RSG gap at side of electrode.

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

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

In a message dated 11/25/02 3:40:37 PM Pacific Standard Time, 
tesla-at-pupman-dot-com writes:


>Hi Ed
>Ted in NZ here
>Looking at the thermal coefficient of expansion for Tungsten (assuming that
>is what you use) is 1 part per million per deg kelvin.
>So if a 200mm rotor heats up by an average of 100deg delta L is 0.02mm
>
>I'm not a mechanical engineer dealing in this stuff so forgive me if I've
>stuffed up but as you can see with tungsten delta L is pretty small.
>
>Other designs with other metals will be quite different but all in all
>expansion is relatively small and only a problem with high power, longer
>rotors and very close gaps. Again my problem was with brass rotor of 5mm dia
>220mm long running over 5kva and I'd set up the gaps very tight.
>
>Best
>Ted L in NZ


Ted,

I was primarily thinking of the rotor disk itself growing in size as it 
comes up to speed.  Ever watch the rear wheels on a double A fuel dragster?

Ed Sonderman