Brush Angle vs Commutator Rotation

["Mike (il Matto)" <madmike@digizen.net>]

I noticed that the brushes on my motor are mounted at an angle to the commutator
rather than perpendicular to it.
My questions are
Why?

Which way does the commutator move relative the beveled brush, hitting the
pointed end of the bevel first or last?
point first:
  / / 
 / /  brush
----> Commutator direction

point last:
  / /
 / /  brush
<---- Commutator

If one is running the motor reverse, does this cause excessive wear, or
resistance or what?


-- 
Mike Shipway
madmike@digizen.net
Freelance programmer, solar powered.
Electric propelled.