Needed to figure out what to do with large pip pin access holes on the top
of my accelerated tailplanes.
Needed was major surgery on the inner and outer bushings to make them much
more better stuck, which garbage picked pieces of a Carbon Fiber rowing
skull oar (tie inner and outer from bottom) did a nice job.
I have read of some that use plumbing screw on caps, some that remove the
keyring, and use a special tool, or push from bottom and leave a smaller
hole on top, some that cover the top with some sort of tape. Also no holes
or covers on top, no drain and install pip pin from bottom with cap.
I almost went for the pip pin in from bottom with cap, then I began
feeling a bit uncomfortable that if it was assembled and pip pin was not
in place, unless you removed cap, inspection was not possible.
Awe/screw-it!
I purchased from McMaster Carr a 1/4" shoulder Stainless Steel 1/8" allen
cap screw, 3" long with 10-24 threads. The cap is 3/8" diameter. I also
purchased 1/4" ID and 3/8" OD -10 O rings, but they are in fact square and
have 4 sealing lips. A simple lathe job of making a 10-24 tip out of
aluminium, and a 1/4" hole tube for top with a 3/8" nest.
No drain on bottom, just screw in from top, the Square-ring does the
sealing.
I had 2 5/40 stainless ball plungers with plastic ball for the bottom up
job that I will not be using, so installed on the top tube and made a
groove in the shoulder screw.
The diameter of the shoulder screw is the same as the pip pins. The
Stainless used is not awful hard or strong, but I kinda think a 1/4" birch
dowel is probably strong enough. You can buy the same part from McMaster
in steel which is twice as strong and harder.
Ron Parigoris.
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