Initial Prep (Debur, Trim, Drill, and Cut)
2/24/24 - 1.2h
4/28/24 – 3.8h
4/30/24 – 1.2h
5/1/24 – 0.5h
This is my first foray into the world of fiberglass parts, so I was very hesitant to jump in and begin. I'm to the point, though, where the garage is starting to feel a bit cramped and the wings may have to be relocated to a storage location soon, which means I need to get at least the rough work on the wing tips done. The good news is this is just the first chapter in a longer wing tip book. No special skills are required other than a little care and patience (like everything else!).

The first step is to trim the edges of the wing tips leaving a 1/2" flange. The wing tips have indented flanges molded into them, and I used a roll of 1/2" wide electrical tape to measure the edge of the flange. That turned out to be a good approach – just cut and sand up to the tape, and the result is a decent 1/2" wide flange. The plans don't explicitly say how far aft to cut, and the indentation in the mold ends approximately where the top and bottom wing skins end. Go ahead and continue the tape in a straight line all the way to the trailing edge, and cut the edge of the wing tip down to the tape around the entire wing tip. The aft portion of the wing tip will get some additional cuts later, and cutting the entire wing tip even now is easier and makes later cuts easy, too. I used a Dremel and plastic-cutting wheel to trim the wing tip edges, and then took a small hobby file followed by 120 grit sandpaper to clean up the entire cut to the tape edge.

The wing tips can be loosely test fitted into the wngs at this point to locate the aft edges of the top and bottom skins on the wing tip. All of the cuts from this point forward are referenced to the aft skin lines.

The next cut was a little confusing. The plans say to notch the bottom flange of the wing tip 1/8” deep up to a point 1/2" forward of the aft edge of the bottom skin. The purpose of the notch is to allow the wing tip flange to clear the aileron hinge bracket. The key phrase there is “clear the aileron hinge bracket”, not the aileron hinge itself. The aileron hinge bracket is riveted to the aft edge of the outboard wing rib with the forward portion of the bracket extending about 1/2" forward of the bottom wing skin. Cut off the 1/8” wide portion of the bottom inboard wing tip edge starting 1/2" forward of the aft edge of the bottom wing skin all the way to the trailing edge. You can also cut off the 1/8” wide portion of the top inboard wing tip edge starting at the aft edge of the top wing skin to the trailing edge.

The final series of cuts are to allow a minimum 3/16” clearance between the wing tip and the aileron. I made a series of 1/16” cuts to the aft portion of the wing tips until I got about 2/16” clearance. I'm going to leave that clearance for now, and come back later with some finer grit sandpaper to open up the gap and smooth the edges. That will be in a later chapter of the wing tip story. For now, I have trimmed the wing tips to the point where they can be fitted into the wings, aligned, and modified with nut plates for attachment to the wing tips with screws. The final gap will come after the final fitting of the wing tips into the wings.
[Dremel with PVC Cutting Wheel, 40” Straight Edge, Spring Clamps, 1/2" Electrical tape, Sanding Blocks, 120 Grit Sandpaper, Hobby File]