After a long week at work and a busy saturday, it was a pleasure to get back to the airplane, especially since one of the last few items I can work on before the wing kit arrives is the trim tab motor.

Specifically, getting the motor (which is mounted to the access plate), mounted and rigged with the pushrod.

I haven’t done as much research as I wanted, but I figured out that I should figure out where the motor’s travel is centered, then size the pushrod to fit a faired trim tab.

First, let’s run the motor all the way up (jackscrew away from tab, tab goes down, forcing the elevator trailing-edge up) and measure.

Then let’s run it all the way down (jackscrew towards tab, tab goes up, forcing the elevator trailing-edge down) and measure.

Well, “measure” here meant estimating it’s total travel once the side pictured above (not below) went sub-flush.

So 20 mm of travel, so I want to rig when it’s 10mm away from one of the stops. 16mm protruding, minus 10mm is 6mm.

I moved the motor using an old battery until the jackscrew was 6mm protruding, then screwed the clevises in both sides of the pushrod, then measured from the center of the tab hole to the center of the clevis hole.

It was 92mm too long.

Removed the clevis, trimmed the pushrod by 92mm, reinstalled the clevis, used a small clamp to fair the tab, and attached.

1.0 hour tonight. A fun hour.