SRSG gap distance?

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

Original poster: "Luke" <Bluu-at-cox-dot-net> 

Let me see if I have got this right.
In a static gap the adjustments are made by varying the distance of the gap.
With a rotary gap however you do not adjust this distance.  It is set and 
the thing that makes and breaks is the physical motion between electrodes.
Is that it?

And if this is all true how do you determine how close the gap should be on 
a SRSG?
Is there a formula for this?  Or is it just set really small and the 
distance doesn't really mater?

Luke Galyan
Bluu-at-cox-dot-net