Chapter 19 |
Wings & Ailerons |
The longest chapter...at least I think. Each wing takes about 100 hours to complete. There are so many things to do and get just right. Plus these things are big!!
Beverly and I cut the cores in the summer of 2001 after we finished with the canard and elvevator cores (I had to take advantage of the time, since she would be delivering a new baby in a couple months!). These are a lot bigger, and need more cuts in each set of blocks. We finished all the cores for left and right wing in a couple of days of work.
I cut the jigs from 3/4 in particle board which seemed to be strong enough. At first I tried to use dowels and a strip of plywood to hold the joints together. This was not a good idea and I ended up using wood screws through the plywood which held better but these things still seem a little wobbly if you ask me. Next problem that I had was that I couldn't jig the wing to the floor because my floor was very uneven. I learned in Chapter 10 that I don't like bondo on my jig table because it always takes a piece of the table with it when it 'pops' loose. So I got some right angle brackets and attached them to the bottom of the jigs and then the jigs to the table. Now the biggest problem that I face is having to work on a ladder to get to the shear web.
BIG OOPS! Ok, my first major mistake (which I would find would not be my last). When I tried to jig the right wing onto the table I found that I always had a 2" gap at the trailing edge. It took a little while for my tiny brain to figure out what went wrong. But I didn't double check my measurement before cutting the blue blocks to the correct size and angle. The top measurement was an inch off in the wrong direction. At this point I scraped the center wing core blocks and ordered more. While I was waiting I jigged the Left wing, this worked (because I didn't mess up the measuments). I cut the 2024-T3 parts and the little pockets for the wing attach bolts. I micro'd the blocks together, and then did the shear web. It was difficult getting to the back of the spar cap because the wing was jigged to the front of the table and the table was against a wall. But somehow I managed to get it done and micro'd the Leading edge back onto the wing bottoms. My foam arrived while I was working on my left wing, so I unjigged the Lt and did the right too.
Spar caps were next, and this almost went without a hitch except the spar cap tape from ACS was junk! Every so often the key thread was tied to the spar tows, which reaks havoc on your layup when you try to pull it out. Even worse, I found some of the tows cut and glued (or epoxied) back together!! I ended up getting rid of quite a bit of tape and complaining to ACS. I didn't get anywhere until I sent an email to Jim the president. After the lower spar was done I did the skin, I had tried to precut the UNI cloth, but that didn't work as well as I wanted (in the future for large parts I just roll it off the spool as I need it). The bottom was easy, but shortly after I finished I was at the hospital getting a new baby. Delays, delays, nothing but delays! But she is very cute, so I guess it was a needed break.
Okay it is mid November in Ohio and the temperatures don't favor glassing any more. But I need to get this thing out of the jigs. I got some space heaters and crank them up and they manage to keep the garage at 75 in the day, but wake up temps are around 65. I contact PTM&W industries to get an idea of what effect it will have on the finished product. Scott tells me that it will be fine, but the cure will take much much longer. I decide to do the spar cap and skin all in one day. This ended up taking around a total of 10 hours after foam core prep the day before. As the temps dropped in the evening to around 70 the epoxy kept getting thick and I rushed even faster. I finished, but man what a day, never will I do that again. After 2 days of waiting the epoxy still hasn't reached a fully cured state. So I convince Beverly to let me bring the wing inside to finish curing. Two more days inside and the resin is hard as it should be. Whew! At this point I hung the Lt wing on the wall of the garage and jigged the right wing so it would stay straight until spring when I could glass it.
Spring came and the right wing was skinned, the only problem that I had is that I jigged the wing to the floor for skinning and this made it very difficult to get the overlap on the leading edge correct. Another thing that I did was to dry micro holes in advance of laying the skin. My reasoning here was that uncured dry micro has a tendency to sink into the hole that it is filling when more epoxy is put on it. I tried to overfill the holes but this leads to other problems. Finally, I dry micro'd the holes and divits and then sanded them to shape, it works great but I don't know how close this is to hard shelling since I do not do the entire core. But it is done and now I can move on to doing the ribs and ailerons.
![]() |
![]() |
Bottom spar on right wing | Bottom skin on right wing |
![]() |
![]() |
Right wing top micro'd almost ready to skin | Right wing top skinned |