Chapter 17 - Trim System
Start: 09/01/08
Finish: 03/31/09
Total Time: 14 Hours

Being our Infinity stick grips have coolie hats it seems a waste not to connect them to electric pitch and roll trim. We chose the Strong Pitch Trim with PWM Module for greater control, but didn't want to mount it in the location suggested in the instructions (along the fuselage side). Instead we fabricated brackets that would allow mounting of the pitch trim forward of F22, and attaching to the plans pitch trim bellcrank on the elevator torque tube.

For the roll trim, we chose to implement the Wright/Hanka roll trim utilizing the Ray Allen T3-12A servo. To make the fiberglass spring we wrapped 10 plies BID around a bottle, forming an Omega shape, then laid up and additional 10 plies about half way up each side, followed by an additional 10 plies at the 'feet' alone. Drilling an 1/8" hole in each end of the spring allows for attachment to the servo, as well as to a cable or hose clamp affixed to one of the aileron push rods. A number of people have mounted this system to the firewall and attached to the CS-125L crossover tube that connects the left and right bellcranks. We're a little concerned about the heat in under the cowling causing issue with the trim servo, so we're going to attempt mounting it in one of the wing roots. The servo is certainly small enough, just not sure about the fiberglass spring. Might have to make a slightly smaller one. The wings are up at the hangar, so we'll either make a trip out there to work on it before it get's too cold, or we'll wait until we bring one back for finishing.

Now that the wings are on the plane, we were able to fabricate a bracket attached to the spar to mount the roll trim servo.