I have a commercial project coming up that requires me to build a
display table for a couple of scale model airplanes, one is the Antonov
124. The models actual wing span is approximately 56", nose to tail is
about 53". The airplane has a single 8mm mounting nut and is elevated
from a platform by that mounting nut.

I need to mount the airplane so that it will not spin while on display,
that is one of the current problems.

I have the details figured out, I think. There will be an 8mm threaded
stud coming from the airplane to an elevated post and will do down into
the post 3~4". I plan on embedding a 1" long set screw rod coupling
1/2" into the mounting post. The 8mm rod will go through that coupling
and down another 3~4" into the post.

Finally the question. A single 10/32 set screw, in the coupling, will
tighten into the 8mm threaded shaft. Since this set screw is going to
be used relatively often I have fears of a hex wrench eventually
rounding out. My thought is to use a hex head cap screw instead, with a
larger sized hex head.

Will the cap screw hold as well as a set screw or will a snug set screw
hold as well as a cap screw that is tightened much tighter?

The job of the set screw is only to prevent the rod from rotating, the
bottom of the hole will maintain proper shaft depth.

Thoughts?