Flap System – RV-14 Build

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.