>I fear that too
>little tightness may give a sloppy mating either side of the tufnol bearing
>and too much tightness may be effected by temperature creating binding. It
>has been suggested that I pack out between the inner face of the bush(CS03)
>that mates with the tufnol bearing(CS04) with an ultra thin spacer such as
>a thin plastic medium, but what thickness, if at all?
You are right, I had a puzzling occurence once. Flying on a cold day we
took the airplane out of its (not as cold) hangar and went flying. Fine,
but ten minutes into the flight the roll control went stiff. A certain
amount of thought concluded that the Aluminum tube contracted quicker when
moved into cold air than the Tufnol, so the flanges on the roll control
torque tubes started to grip the Tufnol.
Moral: don't aim for a perfect fit. I never did the sums but if you work
out the contraction of half an inch of Aluminium with a temperature drop of
say 20 degrees and use that as the end float clearance you should be OK. (
I'm too old to do it tonight) Too much clearance will cause excessive
backlash in the pitch control but I doubt you will ever notice. Don't
forget the Flettner strips on the anti balance tabs though. Vital.
Graham
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