Big day today! I started out by fitting the F-770 side skins to the center fuselage.
My left longeron needs to be bent up a little more - about 1/4".
Same goes for the right longeron -- maybe 3/8" for him.
I didn't want to take the longerons out to bend the a little, because that would be been a major hassle. So I brought the vice to the longerons in place. clamped down the longeron using some scrap 1/8" angle held down to the sawhorse by a mondo large clamp. Spread the side skins off, pull up, hit with hammer, repeat. That did the trick. The longerons line up perfectly now.
Next was installing the armrests. They need some fluting as well as adjusting the flanges perpendicular to the web.
One issue with the armrests is they seem to get bent easily. Some people rivet on some angle to them for reinforcement. I was playing around with some stock to see how it would be done. Looks like an easy lightweight mod.
Clecoed and drilled the armrests.
Next was making the bend in the side skins for where it meets the aft skin and the center section bottom skin. Its sort of a compound bend.
I started by making a line where I wanted the bend to be. Also, I deburred the edge where the sharp bend is to mitigate the possibility of a crack forming. I have heard that a crack forming here is somewhat common.
I used the backriveting plate to form the bent line and back drilled some scrap angle to make the bend happen.
After two iterations, it looks like it fits very well.
Feeling cocky on the second one, halfway through the bend I saw a crack forming! Ahh! I flipped out and cussed for about 3 minutes straight. I looked to see how much a new side skin was - $80! I calmed down a little (aka had a beer) and decided to stop drill the crack and see what I could do with it.
Lucky for me, the crack follows the bottom skin of the center section almost perfectly.
What the heck, one more.
Jeez, another one? I guess I was photo happy because of how small of an issue this turned out to be. I am going to make the crack fit in better with everything else there, so basically you will never know. Well, of course you will know if you look at the other side, but who will ever remember?
Finally, I clamped the longeron to the aft fuselage. I have other stuff to do tonight, but this puppy is ready to be drilled. Oh yeah, I also need more #40 and #30 clecoes. I am desperately close to being depleted. I should be able to borrow some in the next day or so.
Last Modified: August 13, 2023