Re: RSG gap at side of electrode.

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

Original poster: "tesla by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla-at-paradise-dot-net.nz>

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
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, November 26, 2002 11:08 AM
Subject: Re: RSG gap at side of electrode.


 > Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<Esondrmn-at-aol-dot-com>
 >
 > In a message dated 11/24/02 2:09:50 PM Pacific Standard Time,
 > tesla-at-pupman-dot-com writes:
 >
 >
 >
 > >Subject: RSG gap at side of electrode.
 > >
 > >Tnx Pete I think that would work well and might have other advantages
too.
 > >I would not want to over state the expansion problem, it arose for me at
 > >very high power and in special circumstances (ie brass rod rotor) and is
 > >very easily accounted for with a small extra amount of clearance to the
 > >fixed electrodes.
 > >Best
 > >Ted L
 >
 >
 > Since I am in the process of building a new rotary gap, I find this
 > discussion interesting.  With the stationary electrodes set to the outside
 > of the rotating electrodes - will the diameter of the rotating electrodes
 > increase when comparing the static dimension to the clearance when it
comes
 > up to speed?
 >
 > Ed Sonderman
 >
 >
 >