Weeks 20-23: Left Wing

I haven't been making as much progress in the last few weeks as I would have liked. After finishing the bottom skins of the left wing I started prepping all the fuel tank parts. I spent all of week 20 working on this, but then managed to have a complete mental breakdown when dimpling the fuel tank skin.

Somehow I thought that it would be easier with the male portion of the dimple die on the bottom (which worked great for the flat skins), but this meant that I had to bend the other half of the skin away from the dimpler arm. Doing this bent the skin against its natural bend, and ended up leaving it dented in a way that I don't think I can use it. At a minimum it is going to be just uneven enough that it will bother me forever, so I ordered a replacement skin.

I have to wait on that to assemble the fuel tank, but I should be able to still finish the rest of the left wing. The weather was excessively hot so my neighbors were not spending much time outside. It took me a few days to catch one of them and have them help flip the wing over. Once that was done I riveted the ribs to the brackets on the front spar, then started installing the wiring.

I had test fit the pitot tube while the wing was still upside down, and had decided I needed to get some shorter #6 screws to mount it. While waiting for those I made a bracket to hold the temperature controller (for the heated/regulated pitot tube). I have seen some builders install the controller directly to the access panel cover, but a bracket just inside seemed easier to me. After forming it and match drilling and dimpling the appropriate holes, I primed it then riveted it to the wing rib and the bottom skin. I used some of the #6 riv nuts I had left over from the right wing tip and secured the controller using a little bit of blue Loctite.

With the controller installed I mounted the pitot tube and connected all the wiring. I am using the solder-sleeves to connect the wire harness to the controller. The next step was to connect the pitot and AOA lines. Midwest panel recommended colored NITRA tubing for each type of line. Their recommendation (which I believe is relatively standard) is blue for the static, red for the pitot, and green for the AOA. The website they recommended (automation direct) was out of the green, so I am using yellow for the AOA.

It took a little research to decide the best way to connect the aluminum lines from the pitot tube to the 1/4" NITRA tubing. I ultimately decided to flare the aluminum tubing and use a NPT to push connect adapter to connect to the plastic lines. The tubing was 3/16" OD, so I determined that I needed a AN3 flare (37 degree) fitting to connect it. I had to order those, the adapters, and a flaring tool to make the connections. I also saw the book "Standard Aircraft Handbook for Mechanics and Technicians" mentioned on a homebuilt YouTube channel so I ordered that as well. That has great information including the recommended torque for flare fittings, which came in very handy when connecting the pitot and AOA lines.

I am now waiting for the second EAA technical councilor visit before I can close up the left wing. While waiting I am working on prepping the top skins so I will be ready to install them as soon as that visit is complete. I also received the replacement parts for the right fuel tank, so once I am done with the left wing I will get the right one back out and complete the fuel tank. As soon as that is done I should be able to start on the fueselage.