Originally Posted by
JSF-TC
Gerald,
Thanks for your comments.
I agree that Frame 3 is not the best structural arrangement, but if you look at a section through the fuselage at Frame 3 with the gear retracted and pipes installed, you will see that there is no space available to close out that frame.
In order to try to ensure adequate structural strength, I am planning on making Frame 3 out of 3 layers of 1/8" 5-ply. Two layers will have the cut-outs necessary for the ribs and retract plate, but the 3rd frame layer will omit these cut-outs in order to eliminate any potential weak points. I may even go to 4 layers, 2 of each. That would make that frame 1/2" thick. See frame layouts below.
If you can think of a better way please let me know.
Paul
Agreed, superb work.
Regarding this high stress are I had a similar problem with my Rotkoski Sabre which I modified to have removeable wing panels.
I faced the ply formers with 3 mm carbon plate, massively stronger but lightweight.
Flight test showed this to be fine.
Good luck with the first flights, next time you are in UK the champers is on ice !!