On Fri, 2 Nov 2012 14:20:33 -0700 (PDT), Sonny
wrote:

For whichever set screw you use, file flat a part of the 8mm threaded rod where the set screw will contact. Re-die the rod, if need be, if the filing messes up the threads on the rod, for screwing it onto whatever. With a flattened side on the rod, either set screw would not have to be tightened so tight.

Sonny
DON'T use threaded rod. Use a good alloy steel "shaft" threaded to
fit the airplane, and a close drop fit into the stand - with a flat
ground on the shaft to take the set-screw.