10-11-25

Before I started to fit the wing tips I researched what other builders had done; there seemed to be primarily two different methods utilized: cup the wing tip over the outside of the wing assembly and live with the resulting bowing of the wing tip, or add some straps to the lower surface of the wing rib flanges to obtain a flush fit.

I opted to add the straps but instead of notching these straps wherever the wing rib flutes were located, I fluted the straps themselves to nestle right onto the wing ribs and I found this method worked quite well.

The straps were made from 0.032" aluminum and after forming I applied alodine, primer then installed the nut plates. I also found I needed to bevel the outboard edges of the straps to make the installation process of the wing tip assembly much easier.

The wing tips themselves did not fit as nicely as I would have liked and I found the edges were not really straight so before trying to fit the wing tip to the wing assembly, I had to trim these edges down to a straight line. At the aft end, where the wing skin ended, the wing tip needed to be notched to fit over the TE rib, a distance of about 0.7" and having a straight edge was essential to making the notch and fitting the wing tip.

After drilling the wing tip, I found there was still some bowing along the upper edge so to solve this problem I cut relief notches into the wing tip assembly and after drilling the mounting holes and clamping the wing tip down flush onto the straps, I filled the relief notches with fiberglass resin and chop. Once that had cured, I applied fiberglass cloth to the inside surfaces of the relief cuts as a reinforcement.

I plan to install the rear position lights on my wing tips so I made a fiberglass housing for these lights which fits over the TE of the wing tip assembly. I have not yet installed them as I am pretty certain I will need to lengthen the wing tip to match the training edge of the aileron once I have that mounted.