Flap System – RV-14 Build

Assembly Tasks

Posted on November 30, 2025December 6, 2025 by Neal

This week I’ve continued with various assembly tasks.

Lighting:

I resolved the issue with the strobe lights, finding I had mis-pinned a molex connector on the wingtip. Once I corrected the pins, everything worked just fine. It took longer than I care to admit to troubleshoot and find the problem. I learned that it’s useful to start by validating assumptions around where your wires are going by measuring impedance and verifying there is a good electrical connection. Then start measuring voltage drop, once you know your wires are going where you thought they were going.

Comparing this picture to the diagram below, you can see the difference in the pinout. This is actually how I left the connector. Previously the female molex connector actually had the correct pins, but the male was incorrect. Rather than switching the male pins, I just changed the female.

How it’s supposed to be wired. I had the right hand side of this correct, and the left hand side incorrect. I changed the right hand side to match the left .

Aileron Attach:

With help from a saw horse with adjustable leg height, I was able to quite easily install the ailerons. I used new hardware, except for the bushings, since I’ve had these on and off a few times. I was wondering if the install would be more difficult than when the wings were in the stand, but I found it the same, or maybe slightly easier.

I installed and final torqued the aileron pushrods, verified they were correctly rigged using the templates. The templates allow for the pushrod between the aileron and the bell crank to be correctly sized to establish the correct neutral point. Later in the week I rigged the stick-to-wing root pushrods per chapter 41, and adjusted pushrod length until I had the neutral point on both ailerons aligned with a level stick base. I was then able to test the stick clearance, and found I need to trim more off both sticks to avoid hitting the throttle (pilot side) and mixture (passenger side).

I hung the flaps and connected the pushrods, adjusting them to get both flaps all the way up, then verified they have enough clearance from the fuselage.

I also secured the wiring for the magnetometer. I had installed this a couple of years ago but hadn’t finalized the wiring. I had plenty of length so I created a large service loop and secured it out of the way of the pushrod.

Calibrating the pushrods took an iterative approach but I eventually got it

Wing tip template helps keep the aileron neutral

Getting the washes onto the bolt that secured the pushrod at the stick base was a challenge. Note, this picture was taken before I torqued up the nut

Flap position sensor

Posted on July 10, 2023 by Neal

Today I installed the flap position sensor. I tried a right angle drill bit to see if I could drill the torque tube without removing it. There’s just not enough room, so I reverted to unbolting it and moving it. I found by sliding it up in was able to get a clear enough line to drill the hole. I used a 12 inch drill bit and flexed it slightly to get square onto the torque tube.

After unbolting the flap torque tube, I was able to slide it up enough to drill the required #30 hole

With the hole drilled, I moved on to fabricating the connecting rod. This was easy enough.

The rod in it’s final shape, just needs to be trimmed

Instead of using a molex connector, I followed the SteinAir how-to video and used d-sub pins and sockets to form the connections. Each wire’s connector is then covered with heat-shrink to insulate it.

Sensor installed, and flap torque tube reinstalled and bolts torqued

With all that done, I installed the rod and then reinstalled the flap torque tube, which was the hardest part of the whole process. Then I mounted the sensor, and stopped for the day. I still need to tidy up the wiring, but will do that later this week.

Firewall fittings and rudder cables

Posted on October 5, 2022October 11, 2022 by Neal

Tonight was a busy night. My friend Simon came over to help me rivet the firewall flanges, and to torque up the nuts on the fuel line.

We were able to quickly and easily rivet the fittings on. I had to modify one of my rivet gun fittings to grind down one side, allowing it to fit squarely onto the head of the rivet without touching the fitting. Because the rivets were essentially glued in place, I numbered the rivets so we could just call out which rivet we were setting.

The brake line flanged fitting before riveting

The brake fitting after riveting. Note the numbering to identify rivets

Torquing the fuel line required Simon on the front of the firewall with a wrench holding the correct clocking while I cranked up the torque inside. With that done, I installed the flexible fuel line and torqued it also.

Next, I installed the NPT fittings into the brake fittings, including the T fitting connecting to the reservoir. I used Loctite 565. I torqued up these fittings, doing two full turns beyond the initial point of resistance. Getting the clocking right on the t fitting took two attempts.

Then I moved onto the flap motor. This required a carefully drilled hole to hold some safety wire. The drilling wasn’t too hard, and the hole turned out exactly how I wanted.

With the hole drilled, I then installed the motor into the fuselage.

Then finally, I routed the rudder cables forward, and secured the polyethylene tubes in place using adel clamps. These protect the spar from the rudder cable, so they are carefully positioned to do so. Getting the nuts onto the bolts was challenging, but I found it possible using tape to hold the washer and nut, and then rotating the bolt until it caught.

Flap torque arms

Posted on October 4, 2022October 11, 2022 by Neal

Tonight I drilled the flap torque arms, then installed them into the fuselage.

The flap motor sits between the pilot and passenger, oriented almost vertically. The motor connects to a lever that rotates an arm that extends under the seats out to the wing root on each side.

The arms are match drilled to the center fitting using a template (same one used for the wings). I had to slowly step up the drill size because the steel was grabbing the drill bits.

Once the arms were drilled, it was disassemble and install into the fuselage. Some grease helped squeeze the arms through the plastic blocks and into position.