I am building a wing section for wind tunnel testing in the University of
Illinois low speed wind tunnel. It is 18" chord by 34" span with a 20%
chord aileron. I used standard aluminum piano hinge for the aileron hinge
and was not satisfied with the amount of play in the new piano hinge
(purchased from Wicks Aircraft). After seeing the posts about the
teflon/stainless hinge pin modification I thought I had found the answer
to the play in my hinge. I ordered the teflon tubing and bought a pound
of stainless welding rod. These are the dimensions of the materials:
original hinge pin .084"
stainless welding rod .061"
dia hole in hinge > .091" could only check with piece of brass tubing
as I don't have a set of drills to verify
diameter.
stainless rod with
teflon sleve .091" but would compress to .084"
The stainless rod easily slid into the teflon sleve and the sleve/rod
assembly easily slid into the hinge. There was still slop in the hinge
after inserting the teflon/stainless rod due to the assembly being able
to compress to .084" but it was a smoother operating hinge. It would
seem that the modification would help prevent new hinges from wearing but
I don't know about using it to repair a worn hinge. Would seem that a
thicker wall teflon tubing would be required. I am on the look out for
such teflon tubing. If anyone finds any please let me know.
A 100 ft. of teflon tubing from McMaster-Carr was $14.00 USD and a pound
of welding rod was $14.00 USD.
Steve Eberhart
newtech@newtech.com
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