Paul,

When I was at the Seven Stock Show, I noticed that all of the rotors were
cast iron.  Has anyone made aluminum rotors?  Is there too much thermal
expansion to use aluminum?  I was also thinking that the rotors could be
made of a ceramic--low expansion, lighter weight, and possibly lower cost.

Steve Brazil

I think it is  a heat issue. The rotors can run 500 F or more.
Titanium seems to work but it is expensive.