Time: 8 Hours
The first task I started back at when I finally got back to my project was to work on the fiberglass wing tips. The plans call for these to be held on with screws so that you can remove them as needed in the future. Many pilot house different things in them like antanaes and remove compass heads to keep them from the main structure where they may get interference. The only thing I’m going to have in them is the landing/taxi/nav lights. One down side to using screws is that when you removed them post painting they always seem to crack and chip. This ends up being a eye sore if you have ever seen them repainted with touch up paint. Our Lears have the same issue and they look bad once you remove the screws for anything. One cure for this on the RV’s is to use piano hinge to attach the tips. This isn’t for the purpose of having anything hinge open or closed but for a hidden, clean hinge pin to hold the two parts together. There are many builder and many directions online for just this task. I have read several and discussed with my buddy Glenn on how he did his and came up with my plan. First up was to drill additional holes in the wing skin between the holes that were for the screws as you will need extra support for the hinge. Then I cut my hinges to length for the top and bottom of the tip.
I then drew a center line on each wing of the hinge so that I could align them with the row of holes I just drilled. I am using two different sizes of hinge combined together, -3 and -4. The reason is so that the hinge center is off center as you look at the seam between the tip and wing skin toward the wing tip. This ensures that the notches of the hinge are hidden and if there was any gap you would just see solid aluminum of the flange. It would also help prevent moisture from getting inside.
The tips have a flange that slides into the wing in the normal configuration. In the hinge method this is removed and used as a spacer between the skin and the hinge flange to keep everything even. So the next steps are pretty easy. First measure the space between the two lines drawn on the hinge flanges, one for the wing side and the other for the tip side. Transfer that measurement into the tip and mark the holes for the tip even with the wing side holes.
The flange on the left of the next photo will be cut off to use as the spacer. I will sand the edge up to the lip to create a tight seal between it and the wing skin.
After I had all the holes drilled I grabbed the Dremel and cut the flanges off. With those cuts I separated the hinges and clecko’ed them to their respective parts, using the removed flange as a spacer on the wing side.
Based on the advice of some builders I planned each of the hinges to have a eyelet start on the aft end of the wing side on both the top and bottom. The reasoning is that you can insert the hung pin just enough on that eyelet on the wings and have it just sitting there ready to go. Then when you grab the tip to attach it you can hold it in place with one hand and use the other to insert the already started pin making this a one person job.
I am real happy with how the left tip turned out and how the hinge looks. I will work on the hinge pin and how I deal with those later, now on to the right side tip. I just repeated the entire process on the right wing as I did on the left side. In the process where I split the hinge and clecko’ed the pieces to the wing skin and tip I realized I made an error on the top hinge. Somehow I got the hinge alignment off and it wasn’t squared up with the aft end of the top skin of the wing. A couple of options was to just cut the hinge overhang off and make it flush. The downside to that would be that there would be just about a 1/3 of an eyelet remaining on the wing side hinge. The other option was to just redo the top hinge, that’s what I did since I had a lot of extra hinge left over. This presented with a new challenge since I have already cut the fiberglass. What I did was thrilled that he inch to the wing skin first and clecko’ed into position. Hi then attach the wingtip using the bottom hinge in it’s hinge pin. I was then able to use the holes in the fiberglass top to match drill the hinge that was underneath. Everything turned out very nice even though I had to go at this one a little backwards.