[Launchpad larry]

Just getting started on my 2 hand rv4 project when I was laying everything out I noticed almost all the ribs have a slight ark to them that the right wing didn't have did I miss something in the plans? Or is it a mater of finesse when skinning.

 

[RV7AJeremy]

Flute?

Sounds like you need to flute the ribs to make them strait. http://www.cleavelandtool.com/Fluting-Pliers/productinfo/FP200/#.UawX_8u9KK0

 

[Michael Henning]

Before you flute the ribs, make sure you mark the rivet locations so that you are not trying to put a rivet in a flute.

 

[Launchpad larry]

Thanks for the heads up on the rivet placement that almost got me on the first few and I understand fluting the ribs but a few of them are pretty bad just wanted to know if anyone has run into that as well

 

[fixnflyguy]

Bowed ribs

Its a common occurence to have "bowing" during the heat treat process as the metal was compressed and streched during forming. Some of my -4 ribs had 1/2 inch or more bow. The fluting (doesnt take much) between every rivet hole goes quickly once you get the knack. As mentioned, establish rivet locations and to make it simple, draw a line on the flange with a sharpie where the rivet will be. you will quickly see how the fluting moves the rib back straight as work along the flange. If you accidently over flute it, simply squeeze down the flute with hand seamers or duckbills. You will also have to do this on all the fuselage bulkheads...