Took about 2-3 hours per housing. Dremel tool, abrasive disk,
 sanding drum, coarse and fine cratex wheels. Checked for
interference with starret machinists scale.

C. Smith

A Dremel tool is a bit under powered :)

Paul Lamar

Hmmm. Not sure what you mean by that. I'll say this, the dremel
never got away from me and nicked the liner anywhere I didn't want
it to. Die grinders, and other high speed pneumatic rotary tools do
that to me all the time. 8-O
C. Smith

I have watched a pro do it. John at Mazdatrix. In his 40 years
working with rotaries he has probably ported a thousand end housings
:) He makes a wood clamp to securely hold the rotor housing and then
uses two hands on the die grinder. Takes him 15 minutes :) The other
secret is you use grinding stones and those sandpaper wrapped
sanding drums. Less "catching" than a bur.

Paul Lamar


Another tip I have found is to use light pressure. Let the burr or stone and
the speed do the work rather than leaning on the grinder to make it go faster.
It is called finesse. You found out it works on women years ago.

Dale Davies