I'm to the point of turning the drive wheel for the belt grinder I'm
building for my son. It'll be 6061 Al, 6" dia. x 2" wide, running on
a 3/4" keyed shaft, and turn up to 3800 rpm. I figure I'll put a
setscrew on the key and another at 90 deg., which will require
drilling from the circumference. I can drill holes opposite to help
balance.

Any suggestions on how to balance this for a hobbyist? I'm not buying
a balancer, but could build something. Or just spin it up and see how
it does? Thanks.

Pete Keillor