If magnetic induction from the amount of current is causing the rattle, larger conductors might stiffen it, might even slow the accelleration (f=ma) enough to reduce the rattle but the magnetic field would remain unchanged. So it would probably still rattle pretty badly.
I wonder if filling the conduit with expanding foam or epoxy might eliminate the rattle...
[This message has been edited by SteveFehr (edited 04-02-2005).]
