The first operation we did was to drill out the #30 holes in the root flange of all the wing ribs.

I made a quick drilling jig out of some 2X4s that hung off the edge of our bench.

Never hesitate to make these little jigs. It, ultimately, saves time and limits mistakes.

I tacked a second board, cut at an angle, to drill the narrow rear spar flanges.

The next step is laying out the rib lines on the shear web of the D spar.

The D spar comes pre-assembled from EarthStar. As Martha Stewart would say, "This is a good thing".

Placing the ribs on the D spar for drilling.

Notice that I'm using framer's shims to simulate the final skin. This is a handy little trick that we use often.

Riveting the ribs to the D spar.

I'd highly recommend you purchase one of these pnuematic riveters. They're quite slick.

Here's the mid-spar section taking shape

Here again, we make generous use of shims to simulate the skins.

Mid spar outer stiffeners.

In this process, we made extensive use of inexpensive, stainless steel rulers and lots of Cleco side clamps. Our recommendation is to get plenty of each.