11/6/2006
Tonight was the night I've been dreading for a long time...installing the flaps. Why? Well, I didn't think ahead when I installed the flap brace, and I dimpled it before it was installed. I've been trying to figure it out in my head how I was going to get the flap hinge on the wing side drilled with dimples being in the way AND the fact that the brace moves away from the skin at the root. Well, it turns out all this worrying was all for not, and the method of installation became very clear when I had it all in front of me to look at.
I started by clamping the aileron in the neutral position again. Then I simply set up a BUNCH of clamps to hold the flap in the correct location. Instead of clamping the hinge on the top where it will go when riveted, I clamped it sandwiched between the brace and the skin. You can see in this picture that the flap brace is far enough away from the skin to allow the cleco clamp in there.
As we move outboard along the hinge line, the brace is closer to the skin, and there is no real way to get a cleco clamp in to hold it. Instead, I used a little one inch C clamp to hold it in place.
Look at all those clamps!! You can see 9 (can't you???) in this picture, plus one on the other end not visible.
With all this set up, and everything nice and true, I drilled the hinge thru the dimples in the skin and cleco'd as I went along.
After all the holes were drilled, I removed the clecos and the flap hinge. I now had a choice to make with the hinge. I could dimple it or countersink it for the flap brace dimples. I've heard horror stories of the hinge deforming badly when dimpled, and I really didn't want to countersink because I would have to add a strip of AL on top of it to get the strength back because the hinge is very soft aluminum and this is now a run-on sentence...I had some scrap hinge material left over that was about a foot and a half long, so I drilled it with a line of holes to test it. The dimples did curve the hinge ever so slightly, but it did not deform AT ALL. Dimple wins! So, I deburred the hinge, cut it in two for the pin insert spot, and then dimpled it. Worked great, and it cleco'd right back in to position.
Left one is ready to rivet, I repeated all the steps above for the right side, and stopped there for the day.
I can see the end of the wings coming!!
2.5 hours