Stupid Response WAS Re: Casting clearance

This may be a stupid response, after all, it is 12:46 a.m.
Any way, Ron Ginger is considering on using wax as a mold release on a
acme form thread, groove 1/32" wide. Would not the wax at the bottom of
the acme thread create a radiused bottom between the two walls,
especially when the rod is dipped, therefore cancelling out the goal of
having the lowest possible clearance between the rod and the epoxy ?

My question:
For those who are using emc/rtLinux, what CAD program [suchas QCad,
LinuxCAD, or ?] and what conversion program used to send CAD result to
emc ?
w.c.gutman