Wings 68.5, Total 531.5 - Deburring and Fluting Wing Ribs

Well last night it became obvious that I have not had to straighten or flute any ribs lately. WIng ribs turned out to be a little bit different than the empennage ribs in that they are alittle less rigid and susceptable to getting bent incorrectly if you are not careful with them. I almost ruined the first rib I was trying to striaghten and flute.

After I figured out the process I needed to follow, it seems to be working out OK, but is taking a very long time for me to get the rib flanges to the point where all of the rivet holes line up fairly straight. I decided to use my 24 inch straight ruler as a straight edge to determine when the rivet holes in each rib flange are lined up correctly. Although I am using the straight edge to check for this, it is still a bit of an art to determine where and how much to flute each rib flange to get everything lined up correctly.

I have to try to find a way to do this a bit faster, but unfortunatey I think that this will only happen by repeating the process on each rib until I find the magic formula to straighten each one in the least amount of flutes possible.

The process is basically to lay each rib flat on my bench, then determine where the deepest point of warpage is located, and flute that part of each flange. Then I lay my long ruler on top of the flange with the straight edge right next to the two farthest rivet holes, and check the remaining holes to see if they are outside the line or inside the line made by the ruler. For the empennage ribs I was using a piece of fishing line with some success, but the ruler seems to work better on tge larger wing ribs.

Noting the position of the rivet holes against the straight edge of the ruler allows you to determine where and how much to flute each rib. ANother part of the process is to then place each rib in my homemade flange straightening tool, adn straighten each of the flanges. You may have to straighten, then flute, then straighten adn flute some more until it all ends up correctly. Each flange should be 90 degrees to the rib web so that the wing skins will sit on top of each rib correctly, and all of the rivet holes need to line up correctly to match the prepunched holes in each wing skin.

So this continues to be a time consuming process, but it is not overly difficult to do. I'll have some pics tomorrow to better illustrate some of the challenges of this.