Weeks 104-108: Wiring/Firewall Forward

In the last few weeks I have been working on the avionics wiring and the fuel system. The avionics rack backplate needed standoffs so that it did not interfere with the formed openings on the fuselage rib. Midwest panel suggested using a few washers to provide the necessary spacing. To keep them in place I superglued them on, letting the glue cure overnight. This worked well as I did not have any issues with them falling off during installation.

I did find that the regular 4mm rivets I had did not have a long enough grip length to accommodate the spacers. I ordered and used some 15mm long rivets instead. To make sure that the avionics rack was secure I decided to rivet the top skin to the rib and firewall. This also included riveting on the cowling attachment strip under the firewall flange. I think this probably was not the right move since I still have somethings I need to access under the top skin. It would be easier without it installed but I will manage with it on, its just going to require some additional flexibility to contort myself into place.

One advantage of having the top skin on was that I could test fit the glare shield to see where it would fit in. This let me make sure I was getting the ventilation components in the right place. I went through several arrangements of all the ventilation components, eventually coming up with a layout that fit with the avionics rack. The method shown in the instructions extended out too far, but I am confident my way will work fine.

To get ready for the center console, I put on the flap actuator and prepped the seat rails. Some of those parts had to be countersunk, and the plastic slides also had to be countersunk to keep the flush rivets from interfering with the seat movement. Those are done, but I am waiting to install them and the center console until I get more of the wiring done.

I also installed the fuel booster pump, which involved match drilling holes for the mount and connecting the hoses with a check valve in parallel. I got this in place and connected the leaving side to the firewall bulkhead fitting. I continued with the fuel lines on the engine side of the firewall, connecting them to the gascolator and Rotax fuel pump. Those also have the heat shield added and safety wired on.

I also started putting the lines connecting the fuel pump to the fuel filter but ran into an issue with the line kinking due to the tight bend required. I added a 90 degree fitting which fixed that problem, but I am unsure if the extra connections are worth it or if I should just use a longer line to try and make the connection without any kinks.

The rest of the time I spent working on the wiring. I had some confusion due to the documentation from Midwest Panel not matching the way my harnesses were built, but they helped me get it sorted out and provided updated drawings to match. I have started putting the electrical components on and have a battery ordered as well as wire and connectors for it. I did find that my version of the harness did not have firewall connectors, so I didn't need to the two additional holes that I added. I made a cover for those with a piece of stainless steel and the high temp gasket I used before, then cut a new piece of firewall insulation to cover it.

The next few weeks I should be getting the rest of the wiring installed and hopefully getting the engine mounted. With the engine on I can work on getting everything connected to it as well.

The big question I have left is paint. I need to see if I can find a local paint shop that can get it done in a good timeframe, or if I am just going to try and do the paint myself.