I finished flanging the edges. All center ribs are flanged (14/.025 and 8/.032). I did a little more deburring on the flange edge. I found it to be easier with the flange bent.
I started cutting the lightening holes. I started with the smallest hole. The first hole was actually the 1 inch hole for the flap torque tube in the .032 ribs. I cut that with a hole saw bit in the drill press. I cut all the remaining lightening holes in the center ribs with the fly cutter.
I started deburring the lightening holes. Several ribs in I trashed one of the .025 ribs on the deburring wheel. The opposite side of the hole edge caught the wheel head on and it took a good bite. It bent the hole slightly but I noticed it stretched the aluminum and distorted the rib. I scraped it. I made a note to myself to not do that again, but I got sloppy and did it again on one of the .032 ribs. This time it ripped it right out of my hands. It also took a big chunk out of the deburring wheel. Two scraped ribs, I hate going backwards.
I had to dress the wheel down and the 6 inch wheel was soon a 5 inch wheel. I decided to rethink my process for deburring the lightening wholes. I had an order for 1 inch and 2 inch deburring wheels so I decided to wait until they arrive to finish.
I pulled out some aluminum sheets and cut a new blank of one each, .025 and .032. I drilled and routed both, deburred and decided to call it a day. Did I mention I hate going backwards?
