Wing work 2/10/24

This covers a couple days’ work. Yesterday we ripped the CW37 aileron bay TE stock down to 1/4” and I got that installed. Today I’ll glue in the triangular support pieces. And yes, I realized after cutting and gluing it all up that the CW37 piece is supposed to be notched for the rib caps. I’ll remember that for the next time.

I continue to be astonished at how light and strong this wing is. I can easily lift it off the bench and move it around; it can’t weigh more than 20-25# without the aileron installed.

The last thing that was really bugging me about the aileron was that the lower edge of the leading edge plywood still wasn’t glued down. I’ve got to find a better way on the next aileron, but this one had to be done so we can radius the lower edge.

Stew’s idea was to make a grooved board for the trailing edge and use that to clamp a board across the leading edge while the glue sets. He used a length of scrap cedar with a groove cut to match the angle of the TE, and we used four bar clamps to apply pressure. In hindsight – I honestly don’t know if just putting a radius on the front corner and wrapping plywood around it would be better or not. We’ll see how this works out.

In other news, Stew has his 4’ CNC machine in and working, and I’m going to put him to work cutting my torque tube bearing blocks out of some UHMWPE stock I have. Better than plywood, I think.

A few more false ribs

I glued up two more last night, and will do two more tonight. That will make 18 down, with 20 19 more to go. I’ll typically take some time at lunch to cut out the cross brace pieces and get everything set up. Then after work I’ll mix up some T88 and glue the ribs up, then let the glue cure overnight. By the next morning I can pull them out of the jigs and start again.

I’ve run out of cross-brace stock that’s been sanded down to 3/32″, so I’ll have to stop while I retrieve the small shop vacuum from the project house where it is now and run some more 1/8″ stock through the drum sander. It’s a pain, yes, but it has to be done.

I’m already debating where to go from here, once all of the false ribs are finished in a few weeks (maybe). I could start on the tail, but that will require a 4 x 8 work surface. The wing spars will require a longer bench, at least 12′ long. I may instead start working on cutting out the large number of nose ribs that will be needed, and the other high volume plywood parts. It’s awfully tempting to set up my CNC router again for that part, but I doubt that I will. I’d have to translate the outline from the printed plans into G-code for the router, and quite frankly I think by the time I got that right I could cut them all out by hand. I’ve seen a couple of guys use a router and a flush cutter to route the nose ribs from a pattern. I’m a little concerned about the radius on the inside corners where the nose rib glues to the false spar. I figure I could either sand a matching radius there, or touch up the corners of the nose ribs with a bandsaw or something. I’ll cross that bridge when I get to it.