Screwin around with a power tool armature (belt sander).

5/16" shaft kind of "flatted" itself on one side in roller bearing. Best option?? :

turn down for hardened sleeve, then A) shrink on, b) locktight on?

or

try to tig it up and turn/grind back to size (Windings on, will I kill them).

uute

I believe I can get a replacement after I destroy it, but I definitely need the practice!