So I am making progress on the sample wing section practice kit from Vans. This practice kit uses all the tools so is very helpful in getting to know my way around cleco pliers and such.
A word about reamers and drill bits; the holes in the parts are prepunched on a very precise CNC machine so everything lines up. If things don't line up, something is wrong. I found the clecos from Brown Tools are professional grade and line up the holes precisely. The prepunched holes are slightly undersized and need to be enlarged to final size. This can be done with a standard drill bit or a reamer bit. The reamer looks like a drill bit but the flutes are straight up and down. I use the reamer just like a drill bit and enlarge the holes to final size. The reamer produces a nice clean hole that is perfectly round and others say less prone to cracking; reamers also tend to leave smaller burrs so deburring seems to be minimal.
Deburring was a challenge. Most of the tools I tried for deburring the holes were too aggressive. I found what works best was a 120 degree counter sink on the end of a tapped rod. And for the skin edges, the old tried and true butterfly deburring tool works great (red handle on bench). For drilling out bad rivets, the drill press was invaluable. I can lock the piece down to the table and use an end mill to knock off the head. It turns out the heads of a squeezed rivet are pretty hard and it is easy to bugger the flight piece if not careful. All the more reason to make the rivets right the first time, quality is never having to say rework. I also made a holder for the clecos. This was suggested by a mechanic friend and was a great idea.
I thought I would get away without having a belt sander, then I realize the reinforcing strips of the practice kit didn't fit without heavy mods. I tried to trim with snips and files, but was not happy with the results, so I broke down and bought a belt sander and added it to my lazy Susan in the background. What a difference. I also tried to rivet with the DRDT2 in the foreground and that was hopeless; there was no way to secure the part and operate the handle while keeping everything aligned. My best rivets were with the Cleveland Main Squeeze shown in the corner of the bench; what a nice tool. I used the close edge dimpling tool attached to the bench in the corner with the rivet gun to dimple the ribs; this was noisy and brutal. The results were good, but it is still too out of control for my liking. So next time I will either use the Main Squeeze or I will make a top guide for the rivet tool to keep everything lined up. The less I rely on my holding things straight, the better the results seem to be. Jigs are our friends.
Also, having the work well secured seems to make it much easier to add a little English to the tools to keep everything lined up as the rivets are formed.
I feel confident that the skills I have tested on this kit are good enough for real parts. Next up this weekend is the riveting the skins to the spars and completing the practice kit, and then having my mechanic friends review and critique.
So I am making progress. Who needs sleep, there is plenty of time to sleep when I am not building.
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Dues paid 2019, worth every penny
RV9A- Status: tail feathers done less tips
Wings done less tips and avionics