Brackets in place

What I thought would be an hour’s worth of work this morning turned into 3-1/2 hours, but I’m feeling good about the end result. I went over to tighten up the bolts on the wing root brackets and install the brackets on the outer portion of the wing, for the N struts and landing wires.

Snugging up the bolts at the wing root went fine. They’re not torqued to spec, I’ll torque all of the bolts during the initial assembly and mark them all with Torque-Seal or some other witness marking paint. With those done, I moved on to the other brackets. I found that with the very slight variations in hole locations, some of the brackets needed a hole adjusted slightly to get everything lined up properly. It was also a real bear getting the bushings back into their holes after varnishing. Let’s just say there’s no play there… they’re fitted nice and tight.

In the end, I got all of them installed and everything lines up the way it should. I need to find one more AN4-16A bolt, but I think I may have one at the hangar. Next step, I think, will be to cut and fit the cover plates for the brackets where the fabric will be glued down where the brackets come through.

Catching up

I’ve missed a couple of updates to work done on the plane over the past week or so. I got the second coat of varnish on the wing, including the aileron. I got all of the bushings in place, and started to attach the various attaching brackets… oops! No torque wrench. And, I can only find one CAW9 bracket. I think I ran out of 3/16″ x 1″ 2024 flat bar stock before I got them all made; I need to go hunting and gathering again. Once that’s done I can finish off the aileron (the lower leading edge needs a pass through the router for its radius) and move on to varnishing the other wing.

More varnish

Man this stuff stinks. I got the wing about 2/3 done, I think. I brushed varnish on everything that I won’t be able to reach after I turn it right side up. Once that’s dry I’ll install the root brackets and flip the wing to finish it up.

Scallops and metal work

Today I had Stew help me mark the leading edge for the scallops, and got those cut. After getting home, I spent an hour or so rounding up and drilling all of the aluminum wing brackets I have cut so far, which is most of them — all but a couple, I think. I seem to recall I ran out of 2024 with one or two left to go. Anyway, I figure I should get them all done up. I’ll need to cut bushings, mount these, and get the fabric stiffeners cut and fitted — along with varnishing the wings — before calling these two wings “done”. Oh, and I’ll need to get the final torque tube bushings milled out and mounted.

Wing work thru 2/20

Top and bottom leading edge plywood has been scalloped. That wasn’t as big a chore as I thought it would be. We used a thin stainless scale to establish a curve between each pair of ribs, marked along it with a pencil, and cut the wood with a utility knife. Some cleanup with sandpaper and Bob’s your uncle.

I’ve made a few iterations of the bearing block. Today I’ll print a couple more test pieces and I think I’ll be done. They fit great, the aileron is very well located, all in all I think it’s a lot more precise than a piece of plywood and a chunk of PVC pipe.

I’ve been preparing some of the wing attachment fittings. I have one or two of each part drilled with 1/8 pilot holes; I’ll use those to match drill the rest, then enlarge the holes for the AN4 bolts. The biggest question was hot wo round off the ends. For that I drilled a 1/8 hole exactly 1/2 inch from the disk on my disc/belt sander. Now I can use the tail end of a drill bit as a pivot pin and put a nice radius on the end of the fitting. I’m glad I kept my gray Scotch-Brite wheel on the bench polisher; it makes quick work of cleaning up the ends of the AL bars.