In a message dated 23/11/97 22:20:16, Dave Watts wrote:
<< did the mod by leaving the old tailwheel spindle and rudder control system
as was. I removed the fork mounting lugs.... >>
G-EMIN's new tailwheel installation has been compleded similarly, but without
cutting off the lugs - a 3/8" steel rod was inserted instead of the old fork
pivot bolt. The loops at the end of the springs were then passed over the rod
ends and set to the required arm length with washers, spacer and split pins.
With the original mounting intact the old wheel could be put on again to get
you flying (e.g. in the event of a spring arm breakage). The calculated cg
shift is little more than the intended way - for although the old wheel mount
is retained, this has 22 in. less arm than the now absent rudder parts further
back. You also have advantage of the solid stops of the original system.
With a rod doing the driving, you only need one run of cable from the spring
to the tailwheel arm.
<<were pushing the aircraft backwards on the rough ground, with one person in
charge of the rudder direction, when we hit a small bump, which spun the wheel
straight round, snapping the roll-pin limit stop that is built in >>
Having read that, I left out the roll-pin stop and did some tests. Pushing
straight back (or pulling back on a curve to one side) is immediately simple
- as Dave found, the wheel goes through 180 with the cables crossing. If you
want to go the other way just, you just move the tail sideways so the wheel
goes round the other side.
I really can't see any snags to this. If you could a) get the wheel to, say
190 deg, and b) be stupid enough to pull/push or taxy forward in such a state,
then cable wind up would ensue, but I haven't been able get into this
condition, due to the tension and spring return force present. And if you
could , it would be obvious in your walk-round.
Spoil my day - prove me wrong
Graham C. G-EMIN
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