Cozy MKIV - Chapter 17

Installing the Trim System

Start Date: January 19, 1997

ch 17 levers I began by drilling the holes in the instrument panel for the roll trim handle mount, and cutting out the plywood backing plate. I floxed the bolts and backing plate in place and covered them with 1 BID. I attached the cables to the handle and cut the springs to length. Then I modified some cable thimbles, attached the springs to the thimbles and the thimbles to the roll trim tab (on the front of the torque tube) with safety wire.

I cut the cable guide supports from plywood, floxed the cable guides to the edge (after softening the cable guides in boiling water) and then glassed 1 UNI over the guides. Next, I floxed and glassed the cable supports to the fuselage sides.

I had to modify the Brock pitch trim part (you'd think they'd actually make the parts to the drawing, no?) by reversing the direction of the bends (apparently, the COZY III part is different, but they don't make two different parts - ingenious, yes?). I then cut out the plywood support, drilled the holes, floxed the two pieces of plywood together, and then floxed and glassed the support in place behind the instrument panel and on top of the nose wheel cover.

I installed the canard, and then attached all the trim parts for the pitch trim. I needed to bend the arms on the pitch trim handle out a bit more to get the springs to clear each other, and I had to bend the arms on the canard belcrank as well, but once I did that, the system worked like a charm.

ch 17 rear landing
brake mechanism I installed all the roll trim pieces and attached the cables to the handle. I threaded the cable through the cable guides and attached the springs on the ends. After attaching the springs to the RT-2 brackets on the torque tube, I realized that I had a lot of hysteresis in the system; i.e. I had to move the roll trim handle over 3/8" before the torque tube would begin to move. Not good. I experimented with many different springs, but none of them made a large difference. Other people claim that many EZ type aircraft with this type of roll trim system have the same kind of hysteresis in the, so I know it's not me. The problem is due to friction in the front torque tube bearings. I'll experiment with some teflon tape and/or roller bearings. (See Chapter 16 for the [semi]-resolution of this issue.

I installed the landing brake mechanism in the rear fuselage. I found it a bit of a pain getting in that cramped region. The only difficult part involved getting the "stop" to line up correctly so that the over-center mechanism would work correctly. It seems to do so.

After installing the center console in the front, threading and tightening the cables, and cutting slots for the Landing Brake Handle, I jacked up the rear of the fuselage and tested the Brake. Works like a charm!

End Date: March 1, 1997

Addendum Start Date: July 19, 1997

landing brake damper In order to try to dampen the motion of the Landing Brake handle while extending or retracting (it had the bad habit of slamming into the stops on either end and pulling the wire out of the nicopress sleeves on one end), I bought a pure damper (not a gas spring) from McMaster Carr and installed it in the center console between the front seats. I floxed an aluminum pad onto the passenger side (inside), then drilled and tapped it for the damper mounting ball. I drilled and tapped the landing brake handle for the other end of the damper in such a position that the damper extends (it's an extension damper) an equal amount when the brake retracts and when it extends.

You can see this assembly here. I'd say that this was a qualified success - it definitely dampens the motion, but not as much as I'd hoped. I still yanked the wire out of the nicopress sleeves once during testing. I reinstalled the wire with two sleeves. The damper will keep the handle from crushing the passenger's left thigh, however.

Addendum End Date: July 20, 1997


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Copyright 1997, All Rights Reserved, Marc J. Zeitlin