Aileron Actuation – RV-14 Build

Trim System

Posted on December 6, 2025December 15, 2025 by Neal

I didn’t have much time this week, but I was able to get the trim system working correctly.

Using the laptop and a long Ethernet cable I was able to use the VPX configurator tool on my laptop to send power to the trim motors. I was pleasantly surprised that both the roll and pitch servos worked correctly. I carefully verified that the orientation was correct. It would be easy to reverse either one. For example, the elevator trim tab moves up and down just like the elevator, but it has the opposite effect from the elevator itself. Pitching “up” causes the elevator trailing edge to move up. Trimming “up” causes the elevator trim tab to move down, not up. It moves opposite the elevator, providing a force that moves the elevator to change the aircraft’s pitch.

After confirming the motors were working, I was able to set the correct max, min, and midpoint settings for both servos.

I then worked on mounting the aileron trim brackets on the right wing aileron pushrod. These connect the springs from the servo control arm to the pushrod, actuating the aileron.

Aileron trim servo. The servo mounts onto the access panel at this point. Springs will attach to the holes in the end of the arm, and extend to the brackets on the pushrod.

Diagram of the aileron trim system showing the springs and how they connect to the pushrod and servo arm

Using the laptop to run the trim motors and to set the trim limit parameters

VPX config tool. The whole electrical system can be configured and activated from the laptop. The blue Ethernet cable is a 50 foot cable that plugs into the VPX box behind the panel

Due to interference between the springs and the pushrod, I bent the servo arm to gain some clearance

One last picture before closing this up. Note, the d-sub connector is safety wired together

Wing tip

Posted on May 11, 2025May 17, 2025 by Neal

This weekend I focused on the left wing wingtip. With the flap and aileron installed, I confirmed their alignment, then mounted the wing tip and match drilled holes into the wingtip. The holes in the skin are then deburred and dimples, while the fiberglass wingtip tip holes are countersunk, and rivet holes are drilled to install nutplates.

Checking the alignment between flap and aileron

Using a ratchet strap to apply pressure to hole the wingtip in position.

Match drilling holes into the fiberglass wingtip

Marking and drilling holes for rivets to hold the nut plates

Aileron Rigging

Posted on May 9, 2025May 17, 2025 by Neal

Tonight I installed the left wing aileron and used the templates to find the neutral point.

I got a little concerned when I found the pushrod rubbing on the aileron attach bracket, but then realized that it only makes contact at the end of the aileron travel, which is likely beyond the stop on the other side (once the wings are installed and both ailerons are rigged).

I also found that I wanted to use a combination of the flap and the templates to determine the correct aileron neutral position. Luckily these two methods concurred, so I taped the aileron into position. This will then inform the placement and fine tuning of the fiberglass wingtip, which is up next.

Note the blue template being used to help identify the neutral aileron position

Rigging the pushrod from wing root to bellcrank

Where the pushrod extends through the rear spar and attaches to the aileron. I ended up rotating the pushrod so the manufactured heads of the rivets face the spar and bracket, given maximum clearance

Aileron and flap installed, establishing the neutral position.

Torquing aileron pushrods

Posted on August 7, 2022 by Neal

Today I torqued up all the bolts on the aileron, and lock nuts on the aileron pushrods. The lock nuts on the pushrods use thin jam nuts, so I referred to AC43 page 7-9 table 7-1 and used the 320 nut values. For the short pushrod this was 40, and the longer one, 100 inch pounds.

I applied torque seal on all the nuts I final torqued.

I also took the opportunity to apply touch up paint to the pushrods, painting over the ends of the aluminum rivets in the shorter pushrod.

Torqued jam nut. Note painted rivet ends.

Fuel pump, fuel lines

Posted on August 6, 2022 by Neal

Tonight I reinstalled the NPT fittings into the wing tank using Loctite 565. I also reinstalled the fuel filter and pump, securing the NPT threaded fitting with Loctite 565. I completed the torquing of the flexible fuel line at the pump end, leaving the firewall fitting end finger tight. Once I have installed the elbow fitting onto the firewall, I’ll torque that end. I torqued the nuts on the outboard elbow fittings, setting those to 120 inch pounds, after finding that value on VAF. Then I installed the fuel line between the selector valve and the pump, and final torquing those fittings.

I also final torqued the bolts on the aileron torque tubes in the wing root area.

Torqued the flared fitting between fuel pump and firewall

Final torqued this nut to 120 inch pounds, on both sides of the fuselage

Torque tube bolts torqued and torque sealed

Fuel pump installed, along with the fuel line connecting to the selector valve