ETLB Squawk Forums — Archive

Hey guys , I am working on vmax wings and after compression members and drag diagonals placed pretty much done except the front rib plywood web, I decide to feel the wing up and put some twisting force on it, I was surprised at the flexion of this, of course I know it shouldn't be completely rigid but I have never handled a max wing before, and I know after mounted with the struts supporting this will decrease flexion even more , so I guess I just need to here someone else who has had a max in the air describe to me how much flexion is normal versus (dude your wings going to explode in the air) lol   Thanks for input  J.

Hi
If you have built the wings according to the prints, what you feel is normal. When you complete the "D" section leading edge, most of the flex will be gone. Add the finished fabric, wing struts and you have a heck of a wing.
Bob

Thanks bob! I think your right and the designer put years of input and experience into the plans so ... and I haven't deviated from exact instruction. Thanks for your input.  J

Hey
You b welcome, anytime.
Bob

The struts react all wing torsion. The 'D' tube does its bit as well but not primarily torsion, more for main spar bending.

Totally agree with Bob. Most of the flexing will disappear after the leading edge is wrapped with plywood. If you lift one corner of wing after that, you may still find about an inch or two of flexing at the corner.

I also tried bolting down the wing to my workbench at the 4 points where wing is attached to the airplane ( by clamping down the root rib, and also clamping down the wing at rib #5 (?) where struts attach ). Then I tried lifting a corner of the wing tip. It flexed very little.

thanks guys good info. j