<February 10, 2008>
Armrests & Conical Bend #1
Back at it! After a few weeks away from the project it took me a few minutes to figure out where I had left off. First item on the list was to flute and drill the armrests, then it was time to do the conical bends on the side skins.
I started by laying the F-720 Armrests on the edge of the table, working my way aft fluting between every other hole until about the last 4-6 holes, which didnít require fluting.
Looks good so far, the proof will be in the fit.
They both fit fine, without the need for additional fluting. I am going to reinforce these with some aluminum angle, but I will do that later.
Ok, time to put the conical bend in the F-770 Forward Side Skins. I started by drilling some scrap al angle to the skins. I angled and rounded the edge of the aluminum angle to provide support for the forward end bend. I then clamped the skin to the edge of the table using my back-rivet plate. Subsequent to taking this photo I adjusted the position of the back rivet plate a bit.
With everything clamped tight, I clamped my adjustable wrench onto the angle and bent the skin upward while pushing down a bit on the forward end of the angle. It worked pretty good.
I then reinstalled the skin back onto the fuselage. This was a pain in the butt. After struggling for a few minutes to get it all lined up, I removed the clecos and started over. I found that by first inserting clecos into the aft line of rivets, where the side skin meets the aft skins, I was able to get it all together fairly easily. I then worked my way forward with the clecos.
Hereís the front end of the bend. It came out OK. At least it didnít crack, but I am trying not to get cocky as I still have the other side skin to bend. I am left with a little bit of a gap between the side and belly skin, but the picture makes it look much worse than it really is.
All back together. Again, I found it easier to install the clecos from aft to forward (left to right in the picture) but YMMV.