Safe RSG?

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

Original poster: "Jason Johnson by way of Terry Fritz <twftesla-at-uswest-dot-net>" <hvjjohnson13-at-hotmail-dot-com>

Well today I had a great idea for an async RSG that I could build w/o having to
buy anything and stick together using stuff I had in my garage. It has a ~13"
long peice of .5" Al square stock as the rotor, on a 1/4 horse 3450rpm motor.
It spins up fine and will hit top speed w/o a problem, but to be totally
honest, this thing scares the crap out of me. It sound like an airplane's main
rotor and while it doesn't shake really at all the shaft on the motor is 3/8"
and that doesn't leave much Al on either side, and it has two 8-32 holes tapped
right in the middle at right angles to the shaft (for set screws). I calced it
and the ends of this thing are moving at just over 133mph (212kph), which
didn't seem that fast until I saw it going! How much stress can Al take? I
don't want this thing to come apart! I have no doubt that if I was in the wrong
place if/when this thing came apart I'd have a hole in my chest. I don't mind
this thing if I can just build a "blast shield" around this thing and not worry
about it coming apart. Also I'm pretty sure that this stuff isn't pure Al, but
I don't know what alloy, maybe 6061?
 
Jason Johnson