Rib modifications

I built all of the wing ribs exactly to plans, per Sheet 1 of the plan set. Unfortunately, that sheet has not been updated since the rear spar was changed from using 1/2″ square spar caps to 3/4″. As a result, the X braces just aft of the rear spar were way too far forward in all of the ribs I built — all except for the 16 aileron ribs, which don’t get those X braces. Installing the rear spar would require extensive trimming or notching of the geodetic stock — I just wasn’t happy with that. Plus, there’s another piece of square stock on the aft face of the rear spars on the upper wings. It already needs to be beveled to clear the ribs, and with the braces in place would need to be cut down to almost nothing.

So, out came the razor saw. I cut those two X braces from every one of the ribs, cut new ones, and glued them in place with enough clearance for the rear spar. It was a couple hours’ work, but since I have a lot of extra rib geodetic material wasn’t that big of a deal. On the bright side, I got to test the glue joints on all of the pieces I pulled out. We want the wood to fail before the glue does. Every single one of them broke the brace or separated it along a grain line before the glue gave up — 100% successful tests. That was not unexpected, but was reassuring nonetheless.

Now we can move forward with assembling the wings.