As you might know, I'm fitting an aluminum tube (6061 .065" wall thickness) over the gear sticking out of a motor shaft. It fits perfectly IMO. So now I either glue it or key it (if "key" is the right terminology). I'm confident that my glue will do the work, but I'd like to key it to make removing and replacing the aluminum tube easier.
The motor and its gear have been pressed and glued against a 2 x 4 so that it is secure during drilling.
I need to know what size hole. I plan to drill with a cobalt bit and then fashion the shank of an inexpensive equal size bit for the key.
I'm planning to go all the way through the gear/shaft/gear so that the key will stick out from both sides and the aluminum tube will be torqued on opposite sides.
By the way. Would there be an issue with just drilling a shallow hole into the motor gear and using a key to turn the aluminum tube from one side only? Does that throw things off balance? The motor will be spinning at 5,000 to 10,000 rpm.
The motor shaft diameter is 1/5". The gear diameter is about 1/2". The gear length is .3".
Should I use a 5/64" or 3/32" drill bit? I might be able to do the drilling with a smaller 1/16" bit, but is a 1/16" key diameter big enough to turn the 6061 .065" wall thickness aluminum tube?
Will that drilling risk loosening the gear on the motor shaft?
Thanks.