The ailerons and flaps require a super flat 8 foot surface that also has open space under it (to eventually flip parts over and let the clecos stick down through the table top). My workbenches are pretty flat, but not quite consistent enough to just use them on their own. So I took out a second mortgage and went to Home Depot for a 4x8 sheet of 3/4" particle board that I could rip to 2x8. Van's instructions say to build a box out of 2x4s and just put the sheet on top of that, but I'm not sure how that would ever end up flat. Maybe I've just been unlucky, but I can't say I've ever seen a 2x4 that was actually flat. I had some leftover pieces of 3/4" plywood laying around, so I ripped it down into strips and build the supports that way. Because these were kind of piecemeal, they don't provide support like 2x4s would. They just provide the consistent gap under the sheet that I'll need. Setting on top of my workbenches, they are solid though, and after a few shims under the legs, perfectly flat across the 8 foot span (not level, but flat - I never bother leveling anything since the concrete floor has a pretty significant drainage to it). The other 2x8 piece of particle board is just laying underneath and isn't attached to anything. It's not really necessary with my setup. That's just the easiest place to store it for now.
With the table top checked off, I got back to working with metal. The ailerons have a heavy steel tube that acts as a counterweight in the front edge of the aileron. This tube has to be drilled to match the end nose ribs, as well as the skin. It's a little hard to tell what's going on in the picture because the skin is still flipped around backwards - this gets it out of the way, but still allows it to keep the nose ribs set at the right spot while marking the tubing. The tube sits on two flanges of the nose rib. I lined it up side to side and marked the tube through the rib flange holes. There are two holes on each end. I also made sure that the aileron spars were clamped down and flat during this process. I've heard of an issue where people drill holes in the tube, only to realize they accidentally twisted the spar a little while marking it. Once it's all assembled, the spar is what will twist to accommodate any off holes in the tube. At that point here's no saving anything and the aileron has to be rebuilt due to twist.
I was afraid the steel would be awful to drill, but it really wasn't that bad. I used a V-block and drill press to drill the holes with a 3/32" bit, then finished with a 1/8" bit in a handheld drill (just for efficiency, so I didn't have to keep swapping bits around on the drill press). The tube needs be temporarily attached to the ribs to do all of the normal pre-assembly work on the ailerons, but clecos get in the way of the skins and can't be used. Van's says to put pop rivets in the holes and just drill them out later when it's time to take everything apart for deburring and priming. I just slid a couple of rivets into place and put tape over them to keep them from coming out. They hold it plenty firm and will be a lot easier to get out than pop rivets.
As is usually the case, starting a new portion of the build tends to come with a head scratching session. That happened with the skins. The skins are slightly different, but have no markings that indicate the orientation for top/bottom/inside/outside surface, etc. The drawings aren't much help either, since they aren't detailed enough to really provide many clues as to how the skins should be arranged. It took a lot of flipping things back and forth and laying the spars in various setups, but I finally got it figured out. Needless to say, I marked it up really well, and I'll have to take special care to ensure I get things marked again after they are primed.
The first step with the skins is to match drill the stiffeners (I'm doing both ailerons at the same time). The ailerons only have one rib on each end. Everything else is supported only by the stiffeners. That makes it relatively important to keep things flat while you assemble so you don't create any kind of a warp or slack spot that might oil can later. To do this, I just drilled and clecoed directly into the table top. The one bummer I have to deal with is the fact that when I received this wing kit, one of the aileron skins was bent up at the end. It's extremely thin aluminum. I think it'll be fine once I've got everything put together, but I'll keep an eye on it. It'll likely be yet one more spot where I get to use a touch of filler before paint to make it perfectly smooth.
