RSG rotor mount

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

Original poster: "Steve White by way of Terry Fritz <twftesla-at-uswest-dot-net>" <slwhite-at-zeus.ia-dot-net>

I am currently building a 3600 RPM RSG. The rotor is 10" diameter, 1/2" thick
G10. I am currently using an arbor to attach the rotor to the motor shaft. Due
the imprecision of the arbor face, the rotor still has about 1 mm of runout at
the edge. I am also somewhat uncomfortable using an arbor at 3600 RPM with a
10" diameter 1/2" thick G10 rotor. My question is this. Does anyone know of a
suitable device for mounting the rotor to the motor shaft? A pulley or spur
gear with a flat face come to mind. I am thinking of buying a spur gear from
McMaster-Carr for this purpose. It is quite expensive (about $40). I am
assuming that the gear face is flat. If not, I could have a machine shop true
it up. Does anyone have any better ideas? Any suggestions appreciated.