carbon bellcranks are molded with high-temp epoxy and continuous carbon
tow. The weight of these bellcranks are between 7 and 8 grams each
without the leadouts and pivot post. The installed weight will
depend on how long the pivot post is and the type of leadout material
used. The leadout holes are bushed with 3/32 inch ID brass and the
pivot post is 1/8 inch music wire. The pivot bushing is oil
impregnated bronze to provide a smooth long lasting bearing surface
without any wobble to last thousands of flights. The pushrod
bushing is machined to tight tolerances from phosphor bronze to provide a
slop free fit with 3/32 inch music wire. If a Rocket City ball link
is used the pushrod bushing can be tapped to accept the 4-40 bolt. If this
method is used a 4-40 lock nut will need to be added to the 4-40 bolt. The
bellcrank is positioned on the pivot post by two retainers. The
large retainer supports the bellcrank from the bottom while the small
retainer is at the top. The best way to install the retainers on the
pivot post is to use JB weld epoxy. When solder and flux is used
there is the chance of contaminating the bearing and pivot post with flux.
If the flux is not neutralized it will cause the music wire to rust.
JB Weld is a high temp aluminum filled epoxy that adheres well to
steel. The low weight and tight tolerances of this part make it a
natural for today's modern aerobatic aircraft.