Finishing Aileron; Wing Step Skin Try 2

Posted On June 3, 2019

I had a heck of a time getting the aileron to line up properly with the trailing edge of the wing and the flap. I wound up using a technique that involved putting some tape on the skin overlap, twisting the aileron by hand while on the wing, taking the aileron back off, then setting rivets. I had to use a reamer to open up some of the holes so that I could set the rivets with the aileron twisted to match the wing. It was very much a trial-and-error process, since I couldn’t find a way to set alignment once and then rivet the skin.

At first I cleco’d the edge and then used blue painter’s tape to hold the skin in place so that I could remove the clecos and check fit

I needed a stronger tape to hold the skin down, so I switched to strapping tape

I marked some black lines over the skin overlap joint to make it easier to see if the skin was still aligned after taking it off the wing

As you can see from looking closer, the holes don’t line up very well after the aileron has been twisted for alignment. I use a reamer to open these holes up.

I guess it was worth the effort; the aileron alignment looks good

Next, I wanted to install the wing step skin so that I could call this wing finished for now. TAF sent me a replacement skin along with the fuselage kit that I received recently. This skin doesn’t seem to fit either; just like in my earlier post, the holes on the flange don’t line up with the holes on the ribs or lower skin, so I can’t get clecos in.

I decided to try drilling the holes, and as I expected, I ended up having what looks like slots. I am considering just going with this skin as-is; I don’t think this section of skin sees much tensile or sheer loads, but I’m checking with the TAF tech support team to see what they say.

Comparing the new skin (top) with the original skin (bottom). On the original skin, match-drilling to the wing results in holes that are **above** the CNC-cut holes, while on the new skin match-drilling to the wing results in holes that are **below** the CNC-cut holes. You can see there are some holes that are less than 2D from the edge, a potential problem.

I decided to match-drill the rest of the holes on the replacement skin, because it lines up better with the flap when installed on the wing. The holes I drilled are the lower set of holes, some of which are marked with black arrows. I used a file to open up and smooth the adjoining holes.

This week I am going to build an EAA wing rack; I need to get this wing off my work tables and off to the side so that I can build the other wing, and then begin the fuselage.

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