"Leon" wrote:

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.
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Set screw is a failure waiting to happen IMHO.

How about an 8mm lock nut that locks the 8mm stud on the plane
to the mounting post below?

Lew