Rib Fluting problems

[Mark Henderson]

I just started fluting the wing ribs tonight. Before starting I watched Alan Gilmore's video and read every post I could find. It all seemed relatively simple, til I started at least. I am having problems with the ribs warping side to side. I have no problem getting either the top surface, or the bottom surface flat, but not both. When I get one side done and move to the other, it messes up the side I just finished. The hardest part is around the notch machined in the upper web of the rib. The rib wants to flex at this point. The rib can be made to lie flat with minimal pressure, but I can't seem to find a way to flute the rib to keep it that way. What am I doing wrong?

 

[sglynn]

too pickey

You're probably just being to picky. I just finished my wing ribs, tank and leading edge and I could flute the ribs flat sort of. Like you said, sometimes working on the opposite side screws up the first side. Also, making the flange 90 degrees changes the flatness so you have to do a redo. Also, they do an oil can kind of thing flopping back n forth a bit. I think the major point is to get the holes in a line best you can. When I drilled and riveted, I didn't notice even one place that things didn't line up. They went together fine. have fun

 

[JonJay]

Pretty common

It is very common for some ribs to slightly warp. What you are trying to do is straighten the flange. If both flanges are straight and the rib lays flat with minimal pressure, you should be good to go.

 

[RyanM]

Mark,

I had the same issue/concern. See this Thread.

I've built both of my tanks, and started on the outboard leading edges, and my concern wasn't one. Everything fit together excellent.

If for some reason, when you cleco it together, and it doesn't seem right, then take it apart and tweak it. But, if you can get the rib to lay flat on a table with a little pressure, you're golden.