rotarys (update)

Hi All,
	After checking with the local supplier on the cost of "kite" brand tufnol
I was pleased to find that it is not as expensive as I at first thought. 15
UKP (10 USD) for a 12" x 12" sheet of 3/8" thick. This is much much cheaper
than G10 which was about 125 UKP (83 USD) for the same size. As I have to
buy a 12" x 12" sheet anyway I might as well make the rotor 12" diameter.
If I do that what size motor should I be looking for? I am thinking of
using 8 electrodes using Brent Turners design of brass bolts with grub
screws to hold the electrodes. If I design it for 5 kw what size electrodes
should I use? Stilll haven't decided whether to go for sync or async yet,
it might be down to what motor I can find. Am i right in thinking that if I
use an async motor with a rotor of this size I could be pushing the limits
of the tufnol at the speeds it will be running at. I am going to use this
gap with my 8.2 kv 250 ma radar transformer, (the one driving Mike and
Brians coil at the winter teslathon). At some point in the future I might
try and use two of these transformers in series so I want to design my gap
with that in mind. 
Any feedback on this most welcome.

bob golding