Upper Wing I

4/2/2007

All ribs were filed at a small angle within the spar openings to accommodate the 6.5 deg sweepback, then threaded through the spars. The compression ribs were then glued in place along with the compression struts and the drag blocks. When I came to drill the blocks, I discovered that my copper tube drill jig that I had made for the lower wings was too short, so I had to extend it to suit.

Tip: After drilling the bottom holes in the drag blocks, insert a bolt or a piece of scrap rod in the lower holes while drilling the over-holes. This will ensure that you achieve clearance between the two.

Ply doublers were then added around the I-strut and hinge areas. These all take longer to cut than the lower wings due to the 6.5 deg angle. Then all ribs were glued in place. Spar strips were then glued in place, full width for the rear spar, and 1/2 inch for the front spar.

Tip: If using the spar racks as per manual, ensure that you insert a spacer between the spars near the outboard ends - the last outboard rack ends 3' or so inboard, so the spar centers need to be governed toward the wing tip end.

Another tip: This may seem obvious, but when cutting the compression struts to length, gang-cut them all the same size and make them fit. When it came to cutting these for insertion, I must have been having a bad hair day because I found myself adding a /32...or removing a /64 to make them go in easier at each rib station. Then I suddenly realized what I was doing! If your spar racks are accurate [clones of each other] that really pays off here, but even then, due to wood properties you have to maybe either tap them in, or use a bar clamp on the spars to close 'a hair' - just don't trim the struts individually.

I had started to do all of the above on both wings, but after the drag holes stage, I decided to focus upon the left wing only. This is due to it being a bit cramped in my shop now I have this full 24ft wing sat in there. The pics are really in reference to the next stage, my camera died on me in the middle of all this, so am short on pics.