Calibrating Control Surfaces and Cable Routing

TLDR

• Calibrated all control surfaces:
  • flap, aileron, trim, rudder, elevator
• Routed the parachute pull cable along the center channel
• Rerouted pitot/AoA/static pneumatic lines behind the dashboard for better organization

Details

I spent most of the time performing calibration tasks today. I had to turn the avionics on and off quite a few times, so I disconnected the fuel boost pump power to avoid dry-firing them. Then I started the calibration tasks.

Flap Calibration

I loosened the jamnuts on both flaps so the torque tubes could rotate and move the flaps up and down. Then I put the G3X in configuration mode and ran through the flap calibration process.

On my G3X, the calibration is at: Engine & Airframe -> GP2 Flap -> Calibrate.

I followed the calibration video from Midwest Panel Builders for both the flap and trim calibration. For the flaps, I raised them all the way up and bumped them down a little, then recorded the 0, 10, 20, and 30 degree positions. Lastly, I went to the Flap configuration page and set the partial flap extend speed to 90. Easy. I tested the flap full travel range a few times and let it sit at the 0-degree position, then confirmed the torque tube was in the right position and locked the jamnuts again.

Trim Calibration

Then I moved on to trim calibration (Engine & Airframe -> GP1 Trim -> Calibrate). The three positions required during calibration were full up, full down, and neutral.

Full up/down was easy. To find neutral, I stuck a digital angle measure on the trim tab and set it to 0 when it was parallel to the top skin of the horizontal stabilizer. Then as I moved the trim tab up and down, the digital angle moved with it. I just moved the trim slowly until the readout showed 0.

Rudder Calibration

To calibrate the rudder, I need to ensure it moves 22 +/- 2 degrees on both sides. To measure the movement, I downloaded an app called Protractor from the Play Store and stuck my phone to the side of the rudder. Then as I moved the rudder, the app read a degree offset from the starting point. I checked the offset was 20.x degrees on both sides, so it was within range.

I think I can get the range closer to 22 degrees. I will leave it like this for now and adjust if the turning doesn’t feel right after I get the engine started.

Elevator Calibration

Used the same digital angle measure. Moved the elevator full up then full down. The reads are within range as required by the POH.

Routing Parachute Pull Cable

I spent another yoga session under the dashboard ziptieing the parachute pull cable. There was not much to it, just a lot of twisting and swearing. So far I have crawled under the instrument panel a few dozen times; I think the trick is: you have to be skinny lol.

Routing the Pneumatic Lines

When I connected the pneumatic lines for the pitot/static system, I didn’t have a good big picture of how everything should be routed. So the routing was not great.

The other day when I debugged the fuel boost pump, the pneumatic lines’ routing really bothered me, so I decided to redo them before the panel was fully closed.

I bought some more quick-push connectors and 1/4” lines in different colors. I cut them to size and rerouted them so the lines can be tied to structure instead of flying around behind the dash.