Firewall fittings and rudder cables

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
Front of firewall brake flange fitting.
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.

After torquing the fuel line nut

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.

NPT fitting installed

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.