Sunday, November 10, 2013

Bottom Skins and Flaps

I haven't posted in awhile, luckily more work has been being done on the plane than this blog. Quite a bit of progress has been made on the wings. The right tank is sealed up and waiting to be leak tested. Then it was time to move back to the left wing. We began by installing the rivets that attach the leading edge ribs to the main spar since we had skipped these before.

Left Wing Torque Tube
We constructed and installed the aileron actuation torque tube for the left wing. Getting this setup correct and tight was an important consideration. Having sloppy bolt holes would mean sloppy control feel, and having the part too short or too long would induce additional stress on the brackets. I think that we did a pretty good job of putting it together, and everything is good and tight. We also constructed the push tubes but set them aside until the bottom skins are riveted on.

Speaking of the bottom skins, they are all prepared for the left wing as well. I want to have angle of attack indication in the plane so instead of using the bent tube pitot that Vans has in the plans we needed a mast to attach either the Dynon or Garmin pitot aoa tube to. I went with the safeair1 pitot mast since it seemed to be the easiest to install and was reasonably priced, at least in comparison to some of the other on the market. I wasn't looking forward to making this cut in that large expensive bottom skin, but using the provided pattern and sneaking up on it with the Dremel tool made it not bad at all. The hole isn't perfect, but it's pretty close. There won't be too many people climbing under the wing to get a look at it anyway.

Pitot Mast
We began to rivet the left bottom skins on but quickly found out that the rivets around the flap hinge brackets were going to require a different tool. The flush set that came with the tool kit just won't get to the rivets that sit right next to the brackets. I've ordered up a long offset flush set but it will take a few days to arrive, so it was on to working on the flaps.

Flap Skeletons Clecoed Together

I got all of the various flap parts deburred and preped for both flaps at once as we have plenty of room to work on both sets of the smaller components. The plans have you cleco the skeletons together, add the skins, and then match drill some holes in the nose ribs as well as the trailing edge. The nose skin is one piece that you form around the nose ribs. When I was installing clecos I didn't notice that one of the ribs was not sitting correctly and the forward cleco pushed the front of the rib over rather than going in the hole like it was supposed to. When I match drilled through the skin the holes in the ribs ended up way off as you can see in the picture. It also tweaked the rib pretty good. I'll be having to order up a new nose rib on Monday. This pretty much killed my plan to have one completed flap today but in the big picture isn't that big a deal.

Misdrilled Flap Nose Rib, Note the Scar Near the Front From the Misplaced Cleco
 Until the long flush set arrives I'll continue preping the flap parts. Things are moving along well, and it won't be too long till we can get started on the tail kit.
 
Flap Hinges