Question on Attaching Hubless Gears

[lndnny]

Team 808 was unable to do FIRST this year so we decided to do a 150 lb sumo robot for http://www.nationalroboticschallenge.org/

We've decided to use hubless gears with keys and setscrews because we don't have the extra funds to aquire a hex broach in our current situation.

We were going to drill a hole into the face of the gear and into the bore. Then drill a clearance hole and thread the inch or so near the bore for a set screw.

Is this how teams have done it in the past? Is there a better way? We want to make sure the key stays in place and doesn't widen the keyway.

Our mentor wanted us to see if there was a better way of holding the key in place.

Thanks
Inventor Drawing coming once we build the sumobot
Fully autonomous 150 lb robots + IR Stealth = You can't see me!

Dan and Team 808