On 11/2/2012 5:20 PM, tiredofspam wrote:
The screw type won't matter. Either will hold. A soft screw is actually
better than a hard screw, it will deform where it sets in and grab
better. Some of the better screws made to lock in have brass tips to not
deform the shafts, but bite in on the piece.

I am thinking a cap screw, and a hard SS shaft. I would rather the
clamping screw deform than the shaft. If the shaft threads deform it
may be difficult to pull it out of the hole. And i am going to try to
sell the customer on there being give in the event some one grabs a wing
and gives it a push. Better for the plane to turn than something crack.
Or I could grind the threads off on that end to prevent the above
mention possibility.







Can you make a small cradle for the belly where the screw will go, so
that there is more support and that will help prevent it from spinning?
If just mounted on that one screw point, it will definitely put lots of
pressure on the fuse, and could eventually crack that area. A plane
that size weighs a good amount, and you don't know how it was built.
Ask about a small cradle to spread the load.

Thought of that too. Way too much detail for that, there is landing
gear in that area and the customer wants a clear view. The airplane has
been displayed multiple times, the single mount is adequate. They just
want to to tilt and not spin now.

I think I am going to talk him into going with a snug fit so that there
will be some give in case something hits a wing and there needs to be
give to prevent damage.








On 11/2/2012 4:53 PM, 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.

Thoughts?