Get Rid Of Those Bushings!
Trex 450 Ball Bearing Flybar Gimbal Mod
This photo shows a plastic align rotor head all stock. A screwdriver is pointing to the
only place in the align rotor head that is not supported by ball bearings for smooth, free
and long lasting life of the teeter axis.
We will be changing all that in this modification. You will be required to find
two Trex mixing lever bearings and two countersink screws (ment for being used on
the ball links of the Trex kit), as well as two of the tiny washers used for spacing
bearings in the mixing arms.
The Reason for the mod:
I have flown my Trex SE for well over 200 flights now, and I notice that the bushings in
the flybar seesaw allow for back and fourth play in the flybar, causing slop in the teeter
axis when the bushings wear away. Simple solution. Replace the bushing with
bearings! Read on..
To start, Simply remove the old bushings from the teeter axis of the flybar gimble. Now
find a drill bit to make the OD of the Trex mixer arm bearings you found when you
started reading. Drill out the bushing slot as centered as possible, and press fit the
bearing into the new drilled hole after removing any drilling flash left with a razor knife.
Click the image to enlarge. One side has the bearing installed (front), while the rear
side still has the bushing installed and the new bearing hole has yet to be drilled.
Here is a photo of both bearings installed. A four bearing seesaw gimble!
Time to install it.
Here is the screws and washers with a test fit of the pitch mixing arms.
You need the screws used for Trex ball links.. Like on the swashplate, for the new
bearing screws. Also, dig up two extra tiny washers. The ones ment for the bearings
of the mixing arms work well.
Now slip the gimbal, with no bearings installed in the teeter axis, over the rotor head
and position it over the teeter axis screw holes. Now slide your ball link countersink
screw into the bearings, slip a washer over the back side of the bearing on the screw,
and screw it into the rotor head teeter axis, through the flybar gimbal. When you are
done, you should have something resembling the picture below..
Enjoy! Nice smooth teetering and no slop.
