Patrick's Sling TSi

Weeks 14-15: Wing details & flaps

I was traveling for work this last week, so I didn't get an update done for the previous week and I only had this past weekend to work on the project. I have been trying to get some of the wing details finished before I make a wing rack and move the right wing onto it to get it off the tables.

One project I did get done was drilling the mounting holes in the wing-tip. The instructions say to use a ratchet strap to pull the wingtip into the leading edge with a straight-edge to align it properly. After some trail and error I determined that this meant the strap should go over the leading edge of the wing and the trailing edge of the wing-tip. This pulled the tip tightly into the leading edge.

I used the main spar rivet line for the point to line up the wing-tip with the straight-edge. This seemed to get it close, but some of the mounting holes on the bottom were very close to the edge of the wing-tip, so I adjusted slightly to what looked right to me. The curvature of the tip seems to be pretty consistent on the top and bottom.

When working in this area I noticed some missing rivets that I should have put in before attaching the outboard rib. I was able to get a hand-riveter in the landing/taxi light holes and install those without too much trouble. I also temporarily installed the wing tip light. I need to install the nut-plates on the wing tip before permanently attaching the lights, and I also am waiting on some heat-solder connectors before I can do the wiring for the tip and landing/taxi lights.

I can't build the ailerons until I get the finishing kit, since it contains the eye-bolts that go inside the aileron. I set those parts aside, but decided to go ahead and build the right flap. I noticed that the instructions say to dimple some of the holes, but the parts I have had regular sized holes for 3.2mm rivets. The factory's technical support recommended that I dimple the indicated holes for 4mm flush rivets, as the domed rivets sometimes rub on the wing trailing edge.

I followed that advice, then prepped and primed the parts. I assembled the flap and riveted the bottom and the trailing half of the top per the instructions. The front edge are left un-riveted until the alignment process is done. I then did a test fit on the wing. I added the string between the wing step and wing tip, then after adjusting the alignment started the process of riveting every 4th hole on the flap leading edge per the instructions.

The process is to check the alignment, rotate the flap to allow the center hole to be riveted and then repeat the process moving outward. I think I did this correctly, but I am going to wait until I am aligning the ailerons to rivet the rest of the flaps. This way if it doesn't line up there will not be as many rivets to drill out.

I am waiting on the nut plates to allow the wing tip to be removable. While waiting I finished drilling the mating holes in the tip. I used a method I saw on a Mike Patey video to locate the holes on the trailing edge of the wing tip. In this area the tip fits over the rib, so the holes are hidden with the tip in place.

Mike's method was to use several layers of masking tape (to prevent stretching) and use it as a template. With the wing tip removed I used a drill bit to poke holes in the tape, including some that were already match drilled in the tip. I used those holes for alignment then marked the locations I needed to drill on the wing-tip through the tape with a sharpie. I drilled the marked holes with a small drill bit after reinstalling the wing tip, this way I was able to make sure I was hitting the existing holes in the rib. This method worked very well, and I really had no idea how I was going to do it so I'm glad I was able to catch this tidbit off a YouTube video.

While waiting on the parts I need to finish the wing tip and wiring, I am starting to prep parts for the left-wing. I should be able to fully move on to that soon.

This post is from Patrick's Sling TSi