Week 16: Wing tip and left wing prep

This week I started the process of attaching the nut plates to the right wing tip so it can be attached to the wing, but remain removable. I had previously ordered some 8-32 screws and nut plates but decided these were larger than necessary. I ordered some 6-32 screws and nut plates and while I am happy with the size, I don't like the style of nut plate I got. The screws do not easily thread into the Tinnerman nut plates and tend to go in at an angle. I also had issues stripping out the screws as I was trying to install them.

I decided to order a flat nut plate to use instead. I don't think I need them to be dimpled since the thickness of the fiberglass should accommodate the dimpled skin on its own. There is also plenty of material to countersink the rivet holes to let the rivets sit flush. I also ordered Torx screws to prevent them from stripping when they are installed/removed.

I did find a good process for installing the nut plates that I will be able to use for the rest of them. I first drilled out the center hole to the correct diameter for the screw, then thread in a screw with a nut on it into the nut plate mounted on the outside of the wing tip. I then tightened the nut to secure the assembly in place while I drilled out the mounting holes. With that done I used a hand countersink tool (that I mostly use to deburr holes) to countersink all the holes. The center hole gets opened up all the way through the part, but the nut plate should be securely held by the rivet holes.

When I get the new nut plates I will remove the ones I already installed and replace them as well as finish installing the rest. I also started mounting the Archer nav antenna, so I will complete that as well with the nut plates securing the antenna to the wing tip. I need to make sure that there is a good electrical contact between the nut plate and the antenna so it will be properly grounded to the wing.

While I am waiting for those parts, as well as for my replacement fuel tank parts, I started prepping some of the ribs for the left wing. I am also cleaning up the inside of the fuel tank so I can reseal it properly.