Re: RSG question

>has anyone ever attempted to build an RSG in which instead of having
>electrodes mounted on the spinning disk there are simply holes or slots
>in a disk spinning between two stationiary electrodes?

I just today ran into the following, from a Tesla lecture before the 
Institution of Electrical Engineers (London) in 1892, as quoted in "The 
Inventions, Researches and Writings of Nikola Tesla" (Second edition) by 
Thomas Commerford Martin, Barnes and Noble, 1995 at p.212:

"...I have also used mechanical interrupters in many ways. To avoid the 
difficulties with frictional contacts, the preferred plan adopted was to 
establish the arc and rotate through it at great speed a rim of mica provided 
with many holes  and fastened to a steel plate..." 

(I have not looked into the power levels involved in this mechanism.)

Michael Tandy