YS 61FR : Cut a small circular
notch in firewall to clear Header. File header flange about 2 degrees
to increase it's angle.
Use epoxy to apply fibreglass
inside firewall across gear mount area and back up the inside of the
second former (the one with the wing pin holes). After the epoxy has
cured, don't forget to drill the epoxy/glass out of the wing pin holes.
Reinforce wing butt joint with
glass and epoxy, approximately 1" wide.
Doug moved his throttle servo
to the gear mount plate as shown in the photos.
Replace the wimpy
elevator pushrod with carbon fiber aeroshaft or similar.
The horns supplied will not
allow you to align the pivot hole with the hinge line. Replace them
with some that will.
Beef up the wing mount bolt
plate attachment to fuselage with epoxy and fiberglass.
Replace stock hinges. Doug
used Radio South hinges.
Replace the tailwheel
assembly. Doug made his own as follows:
1- A brass tube with a washer soldered to one end is inserted into the
rudder post balsa. Choose a tube size appropiate to your tailwheel wire.
2- Bend tailwheel wire as shown to form a bearing surface with a wheel
3- In place of a set screw, use a length of threaded rod fabricated
from a long bolt with the head removed. This will act as a tiller arm.
4- Cover the tiller with a piece of fuel tubing.
5- The entire assembly is held to the rudder using a wire loop or flat
stock formed into a loop and inserted into the bottom of the rudder.
Reinforcement must be added
where the long tips of the cowl are screwed to the fuselage. Doug used
nylon inserts CA'd into the balsa to hold the screws.
After a few flights, Doug noticed the
cowling had worn a hole through the first layer of covering, trapping
oil in a small bubble between the layers. A few strips of thin rubber
on the cowl edge will prevent this or stop further damage, however Doug
says it was not possible for him to get the oil out once seepage began.
Doug's CG: 6.75" from leading edge at