I’m in the middle of prepping the wing ribs. There are 54 ribs total, and each one has to have the flanges bent to 90º and fluted between each hole to let them lay flat. I still need to debur the lightning holes and edges before they can be attached to the spars. This is a really time-consuming process, and I’m not even halfway through the process yet.
Here are some of the main ribs and prepping the flanges. You can see how straight they are compared with the picture above.
Here is a close-up of the flutes that are added between each hole. Basically, the edge of the flange is longer than the portion of the flange next to the web when the flange is curved. This causes the rib to bow away from the flange. By fluting the flanges, you effectively shorten the edge to be the same length as the flange along the web allowing the rib to lay flat. This is definitely something you just have to get a feel for. I’m getting faster, but it still takes 5-10 minutes per rib.
