Sep 14, 2023     OP-38-06 - Trim Servo Wiring - (2.1 hours)       Category: Controls

8/25/23 - 1.1h
8/26/23 - 1.0h
This should have been a standard wiring step, but it was complicated by the incorrect installation of the micro-molex connector for the aileron trim system on the WH-00013 wire harness. The first problem I ran into was the micro-molex sockets were installed backwards into the 6-pin housing, which made it impossible to connect to the micro-molex pins and housing I attached to the trim servo. To make matters worse, I also installed my micro-molex connector backwards. Additionally, I learned after the fact that crimping micro-molex connectors is slightly different than crimping larger molex connectors. The difference is the aft and center set of wings are crimped together, and the forward set of wings does not get crimped at all.

Micro-Molex Crimping Video
https://www.youtube.com/watch?v=NCU86Yxnnac

Standard and Mini-Molex Crimping Video
https://www.youtube.com/watch?v=h4xdpWOKBr0

https://www.youtube.com/watch?v=NXg3koRHdTQ

After I came to the realization that the connectors were installed incorrectly, I used my micro-molex pin removal tool to pull the wires and pins out of the connectors. This was a difficult process since the pins were installed incorrectly. I wanted to see if there was a better way to pull out the pins, and I stumbled across the spec sheet for my pin removal tool. It had instructions for use as follows:

Molex Application Tooling Specification Sheet for HT60923A Extractor Tool
1. Insert the tip of the tool on either side of the terminal until it stops.
2. Rotate tool clockwise then counter-clockwise approximately 25 to 30 degrees in each direction, once or twice.
3. Repeat steps 1 and 2 on the opposite side of terminal.
4. Pull on the wire and remove the terminal from the housing.

The spec sheet also included the following note about micro-molex connectors:
NOTE: When a terminal is removed in this manner the locking tangs are damaged and the terminal is not reusable.

The result? I crimped the male pins incorrectly, I removed the pins from both the male and female connectors, I damaged the connectors in the process of removing the pins, and I damaged the pins in the crimping and removal process.

The solution? It was clearly time to start over with this connector, and install new hardware. I also decided to install new wires since the original wires on the harness don't have any excess to clip off old connectors and install new ones.
I decided to order new parts from SteinAir, since they were the builder of the original wire harness. I could not find any of the micro-molex hardware on the SteinAir website (they are on the Van's web store), so I called and was surprised when Stein answered the phone. After a brief intro, he knew exactly what I was working on and what the problems are. He recommended cutting the micro-molex connectors off of the harness, and replacing everything with d-Sub pins and sockets. He directed me to a you-tube video he made for exactly this type of application.
https://youtu.be/f8DCvBV2V4M

Taking the micro-molex connector out of the equation worked great for me, and I think the d-Sub approach will end up working better than the original. The d-Sub pins and sockets are much easier to work with than the micro-molex pins and sockets. The installation is clean, and should be easy to work with. When I connect the aileron trim servo to the springs and wires for the final time, I'll install heat-shrink tubes over each individual d=Sub connection to give them some extra pull strength and insulate the wires from each other. I will also put a second layer of heat-shrink over the entire d-Sub wire connection bundle to keep everything neat and together. I don't anticipate ever disconnecting the aileron trim servo wires, but it should be easy enough to cut off the heat-shrink and disconnect the d-Subs if I need to.

There are a couple of final checks to ensure the trim servo is operating correctly after the wings are attached to the fuselage, but for now I'm calling this section of the build complete.
[Wire Stripper, Flush Cutters, Open Barrel (Molex) Crimping Tool, High Density D-Sub Insertion Tool, D-Sub Crimping Tool, Heat Shrink, Heat Gun]

  Sep 04, 2023     56-02 - Garmin Autopilot Servo Pushrods - (2.7 hours)       Category: Controls

Initial Prep (Debur, Trim, Drill, and Cut)
9/1/23 - 0.6h
9/3/23 - 1.8h
This is my first opportunity to use a tap to cut threads on the inside of a tube. The first step in the fabrication of the autopilot servo pushrods was to cut a couple of pieces of tube to the specified length. The tube cutter did a nice job of making accurate and square cuts to the tubing. I also cut the short (15/32”) stand-off spacer for the roll servo installation since the tube cutter was out and ready.

There was a short piece of tubing left over, so I decided to use that to practice the rest of the fabrication steps starting with drilling out the center of the tube with the #3 droll bit. The #3 bit tracks with the tap guide in my tap and die kit. I wrapped the tube in a layer of duct tape, and then clamped the tube into a bench vise to hold it still and steady. The tape did a good job to keep the outside of the tube from getting damaged by the vise, but it can slip. I found I had to reclamp the tube several times throughout the drill and tap process when it started to slip. My main concern with drilling was drilling straight and center on the tube.

The next step was to tap the tube 1/4-28. I used some cutting fluid on the tube and the tap, and started turning the tap very slowly. The tap does not need a lot of downward force, and the main concern is starting the tap straight with the tube. Once the tap is going, I would complete one turn with the tap, and then back it out two or three turns to help clear the shavings. This process continued until the tap was to the correct depth. After taping the tube, I pushed a couple q-tips through to help clean out the debris from the process. I also pulled a thin cloth with alcohol through the tube to clean it out. The process worked well on the test part, and I was able to repeat that success with the real parts.
[Hole and Edge Deburring Tools, Tube Cutter, #3 Drill, 1/4-28 Tap, Boelube, Tap Cutting Fluid]

Prime
9/3/23 - 0.2h
Priming was similar to other pushrods in the build. I started by priming the interior and ends of the pushrods, and then primed the exterior. I also primed the stand-off spacer.
[Scotch Brite Pads, Dupli-Color Degreaser, Rust-Oleum Automotive Self Etching Primer (Green – Rattle Can)]

Assemble
9/4/23 - 0.1h
Assembly went very quickly after giving the primer the evening to cure. The jam nuts get threaded onto the rod ends, and then the rod ends get threaded into the push rods. The drawings in the plans are scaled 1:1, so it was easy to size the pushrods using the drawings on the page.

  Aug 25, 2023     OP-38-05 - Trim Spring System - (2.7 hours)       Category: Controls

Initial Prep and Prime
8/22/23 - 0.6h
8/23/23 - 1.2h
The aileron trim servo connects to the control system using a couple springs attached from the aileron trim arm to small brackets attached to the torque tube-to-bellcrank pushrod. I separated the trim spring brackets with a hack saw, cleaned up the cut edge with a file, and then deburred the edges and holes on each bracket. Priming the trim spring brackets was also straight--forward and relatively quick with my well-practiced process.
[Hole and Edge Deburring Tools, Hack Saw, Files, Grey Scotchbrite Pads, Bon-Ami Cleanser, Dupli-Color Degreaser, Rust-Oleum Automotive Self Etching Primer (Green – Rattle Can)]

Assemble
8/25/23 - 0.9h
The real trick to this step is locating the trim spring brackets and assembling the system. The first step is to mark the centerline of the trim arm, and then transfer that line to the pushrod while the pushrod is in its neutral position. I used the neutral template for the bellcrank to position the pushrod and hold it in place. I then attached the trim servo assembly to the spar with clecos through the wing access panel attached to the trim servo. This is one instance where it is helpful to have access to the interior of the wing without the bottom skins in place. If the skins were attached, there would be no way to see the centerline of the trim arm to transfer that location to the pushrod. Given unencumbered access to the wing interior, I had room to use a laser line to find the trim arm centerline location on the pushrod.

Another benefit of doing this step prior to attaching the bottom wing skins is the installation can be completed without removing the pushrod. Once the centerline was marked, I used 6” strips of tape to locate the edges of the trim brackets, and I used the laser to find the centerline of the pushrod to align the brackets. From there a couple taps from the center punch located the first hole for each bracket. I match-drilled the brackets to the pushrod, and then riveted the brackets in place.

The final step prior to attaching the wings to the fuselage is to test fit everything. The springs are insanely tight, but I got the springs attached to the trim arm and the spring brackets after a lot of time and effort. After attaching the springs, I cleco'd the trim assembly back to the wing, and noted that the springs held the pushrod in the neutral position. I struggled to disconnect the springs after completing the test fit, and discovered that I could use my duck-billed pliers to open up the end coil slightly to make the spring easier to connect and disconnect. I inserted the pliers inside the connection coil for the trim arm, and then opened the pliers to provide enough clearance to remove the spring. I plan to leave the springs permanently connected to the spring brackets, and I'll squeeze the connection coil shut after I reinstall the trim assembly for the final time.
[Laser, Center Punch, #30 Drill, Rivet Puller, Duck-Billed Pliers]

  Aug 22, 2023     OP-38-04 - Trim Access Plate - (1.9 hours)       Category: Controls

Final Prep (Dimple, Countersink, and Shape)
8/19/23 - 1.1h
The aileron trim actuation assembly is mounted to the inboard access panel on the right wing. The location on the panel is specified in the plans, and from there it is a matter of match drilling and final drilling the holes from the trim assembly to the access panel.

After the holes are drilled, the access panel and trim assembly need to be dimpled to accept flush screws through the access panel into nut plates on the trim assembly. The instructions are abbreviated at this point in the build (“Dimple the holes in the bottom flanges of the Aileron Trim Actuation Assembly flush on the bottom side.”), so you need to recognize that the center hole for the nut plates gets dimpled first followed by the rivet holes with a reduced diameter dimple die. You also need to dimple the nut plates.
[#30 Drill, #19 Drill, Hole and Edge Deburring Tools, 22” C-Frame with #8 Screw and #40 Reduced Diameter Dimple Dies]

Assemble
8/21/23 - 0.5h
8/22/23 - 0.3h
The assembly process starts by riveting the nut plates to the aileron trim actuation assembly. The assembly can be clamped to the bench with good access to the nut plate rivets. After the nut plates are in place, the wing access panel can be attached to the trim assembly with #8 flush screws, and then the entire assembly can be test fit into the wing skin to insure no interference between the skin and the trim assembly. If there is interference, the trim assembly can be removed from the access plate and filed as needed to fit. Fortunately, I didn't see any fit issues with mine.

The other step in this section is to center the aileron trim arm to the neutral position. I drew a centerline on the trim arm, and then attached a battery to the white and gray servo wires to move the arm to a 90-degree angle with the trim assembly housing. That will be my neutral position for the aileron trim.
[Rivet Squeezer, Flat Squeezer Set, Cleco Clamp]

  Aug 19, 2023     OP-38-03 - Trim Actuation Assembly - (0.8 hour)       Category: Controls

8/18/23 - 0.1h
8/19/23 - 0.7h
This is a relatively short step in the aileron trim build, starting with final drilling the holes to mount the servo to the bracket built in the previous step. After the holes are drilled, the servo is attached with screws and nuts. The clearance between the nut and servo was too tight for a socket wrench, so I ended up holding the nuts with a needle-nosed pliers while I turned the screws until they were tight. The other prep task in this step is to strip the five 24-gauge wires from the trim servo, which is easy to do since the wires are completely accessible at this point.
[#28 Drill, Screwdriver, Needle-nosed Pliers, Wire Strippers]

  Aug 19, 2023     OP-38-02 - Aileron Trim Brackets - (3.5 hours)       Category: Controls

Initial Prep (Debur, Trim, Drill, and Cut)
8/16/23 - 0.5h
8/18/23 - 1.4h
The aileron trim system starts with two brackets, eight trim links, and the trim arm. The brackets and trim links are all final drilled #30, and then each part needs to be deburred for final assembly.
[Hole and Edge Deburring Tools, #30 Drill, Dremel with Metal Cutting Disk]

Prime
8/18/23 - 0.7h
Priming the parts followed my standard process of cleaning, scruffing, degreasing, and then priming. The trim links were a little tricky to prime because they are so light that the primer spray blew them off the table! I eventually managed to get the trim links back under control and primed.
[Grey Scotchbrite Pads, Bon-Ami Cleanser, Dupli-Color Degreaser, Rust-Oleum Automotive Self Etching Primer (Green – Rattle Can)]

Assemble
8/19/23 - 0.9h
The first assembly step sandwiches six trim links and the trim arm between the two brackets. I found that cleco clamps between the rivet holes on the trim links did a good job holding the parts tightly together. I also inserted the trim arm with its washers and clevis bolts before riveting the parts together. You could probably insert the trim arm after riveting, but I think the washers would be difficult to install in that tight space. It was a little cumbersome keeping everything together before riveting, but doable. After the riveting was finished, I used a needle-nosed pliers and small side cutters to finish off the clevis pin.
[Rivet Squeezer, 1/8” Cupped Squeezer Set, Needle-Nosed Pliers, small side cutters]

  Aug 19, 2023     OP-38-01 - Electric Aileron Trim Plans - (0.4 hour) Category: Controls

8/16/23 - 0.4h
There are a few tasks I want to complete before installing the bottom wing skins, since I think having unimpeded access to the interior of the wing will make these tasks easier and hopefully turn out better. First on the list (starting with the right wing, and working from the root to the tip) is the aileron trim system. I have found the neutral position for the aileron torque tube - to - bellcrank pushrod, which the trim system connects to, and I inserted the neutral template to hold the push rod in the neutral position for this task.

I reviewed the plans for any potential problem areas, and went through the Bulletins, notices, and change pages on the Van's website to make sure my plans and parts are up to date. I didn't find any changes to my plans or parts, and I was able to download an electronic copy of the aileron trim plans from the change pages section of the website. The actual assembly of the aileron trim system looks pretty standard. There is some electrical work at the end with micro-molex pins (time to get out the magnifying glass!), and the spring brackets for the system have to be mounted on the pushrod requiring precise measuring and drilling of the tube. The trim system mounts to the inside of an access panel, which will require some modification to add dimpled screw holes to hold the trim bracket to the panel.