I have finished installing the new tailwheel on XDY (and done the plenum
chamber and moved the battery to the baggage bay).
I installed the spring and wheel as per the factory instructions, and cut
off the bottom of the rudder as recommended. However instead of recessing
the foam, I made flox corners and glassed the finish level with the cut.
This was because I left the old drive assembly intact, so that I now only
needed a drive to the new tailwheel.
I removed the wheel and its fork from the old spindle. This left two lugs
hanging down that the fork was pivoted on and these were removed with a
hacksaw. This gave me a reasonably flat area that I could attatch a flat
plate to with AN4 bolts. I would then be able to connect the drive cables to
this plate. In fact I spaced the plate away with large area washers all set
up with redux and flow to ensure a flat area.
Now for the dimensions of the plate which would be governed by the hole
centres for the drive cables. I took the plate as supplied for the rudder
and worked out geometrically how the holes in this moved. This told me that
for a rudder movement of 30 degrees the cable drive holes would move 35mm
forward and 37mm backwards. The difference being due to the 6mm offset from
the centre.
Now to translate this to the spindle of the old tailwheel, which moves
through 45 degrees each way. Again using geometry I came up with holes that
would be 102mm apart and 1.5mm forward of the hinge centre.
Everything seems to work ok like this but a call to the factory seemed in
order, especially as a call from Ron Swinden queried whether the wheel
should move through its entire stop to stop range, which mine does not.
Andy informed me that they had not actually measured the travel of their
wheel, as there position was arrived at by trial and error (i.e. set it up
then go and fly it, coming back periodically for adjustments until
satisfactory). His opinion was that anyone who tackled the problem
differently to the factory would simply have to go through the same process.
This is in fact quite simple as all you need to take with you is a drill of
the appropriate size for the small holes and redrill the plate. Inward on
the new tailwheel plate for more movement, inward on the old tailwheel plate
for less movement (unlikely).
The beauty of doing the job this way, is that it is very simple with the
least amount of removal of old parts, so that if someone comes up with a
better/neater idea (getting anywhere yet Graham??) you can still change to
this better idea.
The total job is quite feasible in two days (most of that spent waiting for
resin to go off)
Hope this is all of some help,
Dave Watts 229.
Hopefully flying again later next week.
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