All,
The clamp and Loktite solutions address the problem by by increasing the
friction between the torque tube and tailplane drive bushes, thus reducing
the load imposed by the clevis pins on the edges of these parts to the point
where wear and distortion do not occur. The Loktite answer has the
disadvantage that the friction becomes semi-permanent and could make
disassembly difficult.
Another idea, which may be simpler and less of a design variation, than a
clamp is to substitute bolts and saddle washers for the clevis pins. When
tightened, these would provide both friction and direct loading. The holes
would probably need to be drilled oversize and reamed to be an interference
fit for a 5/16 bolt. Suitable aluminium plugs would be also required inside
the torque tube in way of the bolts (to prevent "ovalling" when the bolts
are tightened) but would not need not be permanently bonded.
The clevis pins in my assembly are only a very slight interference fit and,
given the discussion to date, I would rather fix the problem while I still
have the top off. Grateful for any comment or criticism of the idea outlined
above.
Best regards,
Nick Hammond
XS Monowheel 418
-----Original Message-----
Subject: RE: Tailplanes
Bob,
Very interested in the clamp system as it sounds less 'final' even with the
possibility of heat release (note Duncan McFadyean's reservations/
observations). Do keep me posted as at present the 'plane is in the garage
ready for work on it and I hope to get it back on Kidlington airfield by
Easter.
Regards
Peter D
-----Original Message-----
Subject: RE: Tailplanes
Hi! Peter.
Yes, you are right the TP12's and the TP9 are all stainless. However we are
going ahead with our clamp idea( with respects to John Moran's Intellectual
Property if he insists?) which I'll publish when approved, but I can't see
any structural objection is possible since we are only beefing up rather
than changing existing design. Watch this space.....
Regards
Bob Harrison G-PTAG
Subject: RE: Tailplanes
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