Yesterday I glued up the last full rib (#26) and the first aileron rib. I’m going to call this a milestone. 🙂 I now have 15 more aileron ribs to go, then 34 false ribs. I suppose I should pull out the plans sheet for the spars and see exactly what I need to order for them. I have the BOM, but it doesn’t really tell me what I need to know without looking at the plans too.
I had to look at the plans a few times. It looked like the plan sheet was calling out just one geodetic brace to omit for the aileron ribs, but the locations to mark for eventual cutting didn’t make sense. I finally realized that the text read, “Omit this X-brace for aileron ribs”… as in, BOTH braces, not just the one. Great! That’s two less pieces to cut and glue.
I finally went out and got the second rib jig from the garage and brought it down to the basement. Ribs 24 & 25 are now curing, they will be ready to pull tomorrow evening. My new routine:
Put the first jig on the bench. Cut all the pieces fro one rib and set the geodetic pieces above and below the rib caps, ready to glue.
Stack the second jig on top of the first, cut all the pieces for it.
Mix up enough glue for both ribs (14cc seems about right)
Glue up the rib in the top jig and set it aside.
Glue up the rib in the bottom jig.
Double the completion rate. I’m out of pre-cut geodetic pieces, so now I”m marking and cutting them individually with a razor saw. It doesn’t take much longer, really, and each one is cut exactly to fit.
I’m almost out of pre-curved top capstrips. The comments on the plans say you can bend the spruce dry and glue the ribs. I don’t like the idea of having that much tension on the wood. The nice thing about working indoors, though, is that I can keep hot water hot longer. When I run out of pre-bent pieces, I’ll try the hot water bend method again. In the garage the water cooled off far too quickly. In the basement, I can get REALLY hot water in a capped length of PVC, and keep it hot long enough to soften the capstrip. System 3 says T-88 works fine on damp wood… I’ll try that and see how it goes.
I finally took a minute to go out and count the ribs hanging in teh garage today. Combined with the ones in the basement, I have 22 of the 26 required full ribs. Four more and I can start on the 16 aileron ribs — they are identical to the full ribs, but missing one geodetic brace. After that will come 34 false ribs. I’m considering (maybe) using 1/16″, 2mm or 3/32″ birch plywood for those, just to speed up the process. Haven’t decided yet, and probably won’t do it because of weight. We’ll see once I get to that point.
Progress has been slow, much slower than I planned, but really — building ribs is a pretty low priority. I have knocked out half a dozen in the basement, to add to the I-forget-how-many in the garage. I’ll need to count them up soon, but I know I’m not at 26 yet, which is the count of full ribs I will need.
Got the basement workbench cleared off enough to move rib production indoors. So far I’m only using one jig, but I’ve knocked out two ribs now. I need to get the second jig set up. One rib per day isn’t going to cut it. Sure is nice working in the basement instead of the garage though.
I’ve been wanting to get back to building ribs. The garage bench has been piled too deep to get anything done, and now it’s been below zero for over a week solid. Insulation or no, it’s damned cold out in the garage. Too cold for epoxy to cure, and too cold to work.
So… there’s a perfectly good work bench down in the basement. 8′ long and rock solid, built by Dad back in the 1960s. It’s been pretty much completely covered up for the past several years with a collection of parts, partially-disassembled or -assembled prototype projects and assorted debris from the side business I was running, plus a CNC router that took up about 3′ of it. I have cleared most of it off (much of it into a trash can). The CNC machine is shelved for now; I’ll maybe resurrect it when needed at a later date. It will probably come in handy for cutting the instrument panel and/or nose ribs.
The next issue is containers for the geodetic rib braces. There are 24 braces used in each rib, all of which are of course slightly different. Just enough so that none are interchangeable. I was using paper cups to hold them in the garage, but it’s a completely unsatisfactory solution. In the basement I think I’m going to try stapling taller plastic cups along the back edge of the bench and see how that works.
I’m not moving power tools down there from the garage, so new geodetics will be cut with a razor saw. We’ll see how that works out… it’s one of those jobs I wish I could set up a machine or fixture to do. It’s 24 different lengths with over 40 different angle cuts, so I’m not sure how I’d make that work. Even cutting them out in batches on the band saw meant fine-tuning each one with a sanding block before assembly. It’s fiddly work and tedious as hell. Classic gusseted ribs would be a whole lot faster and easier to build. If I were starting this over I’d probably just depart from the plans and build them all that way; I’d probably have them all done by now.