Thursday, February 13, 2020

Section 56/58 Garmin Auto Pilot Servos

RV14 Build January & February 

Garmin AutoPilot Servs

This was over different work periods, but I have enough now that I think it made sense to make a post about it.

2 Garmin GSA28 Servos and the yaw dampener attachment arm.

My brain wasn't working this day and at first I installed the yaw arm upside down on the servo and had to remove and flip it, Here it is currently on and the servo motor installed in the empennage.

View of the yaw servo back to front.

Getting the pitch servo on.

Working on running the wires. I have some wire bundle lacing from earlier in life in my tool bock and am finally making good use of it! Really helps manage the wires better.

Trying to figure out how I want them to run.

Went to an EAA electrical workshop! This was amazing I would highly recommend it to anyone who wants some hands on experience using the tools to make wiring harnesses and install connectors.

The 2 wires that are loose with pins on them come from the wiring harness that is part of the empennage kit and run back to the pitch trim motor. From looking at the master wiring harness diagram from the Vans website they are suppose to connect into the pitch and yaw harness. Ill do my best to explain below.

The diagram has the loose wire with pins, red arrow, run through the grommet below the mini-molex connector and into the molex connector coming from the common fuselage harness, yellow arrow, represented by the red box. The "red box" molex and the molex in the picture connect and boom the wires are connected to the pitch motor.


From the harness diagram the 2 wires are highlighted.
From the pitch diagram the wires they connect to in the pitch harness are highlighted.

All this said leads me to the 2 issues. 1 according to Garmin the wires come "from" the pitch servo "to" the trim motor and should be shielded, for this I called Stein and they said it was a revision to the G3X manual and Vans specs the harnesses and thinks not doing shielded wire in this installation is ok. 2. The wire were too short to wrap out through the bulkhead and into another connector. So I used my new found electrical knowledge bought a bunch of tools and a label maker and industrial labels cut the wires coming from the servo added a 2 pin molex to them and trimmed the loose wires added pins and the molex and connected them closer to the servo. You can see the molex on the pitch motor harness and the other 2 wires below.


Cleaned up the wiring harness with more lacing in the empennage.

Added a loop up in the wire to prevent chafing over the sharp edge of the stringer.

2 servos motors installed! Turns out ill have to remove the pitch motor and the bracket to install the push rods...More on this in a post on section 36.

Drilling a tube for the pitch motor pushrod.

Tapping the tube. The hardest part was holding the tube from spinning while tapping it.


Pitch and yaw installed, cable management done with lacing and zip ties, and the pitch servo push rod installed. Ive tightened the cable ties and had to cut them off so many times, I got smart and just left them all loose for now.

Garmin AutoPilot Servos 8.0 Hours

No comments:

Post a Comment

Before Start and First flight testing

 R14 Build August & September 21 Testing Getting into the fun stuf!! Putting gas in for the first time. Have the airplane up to get 15 d...