Wingtip ribs

September 22, 2012 – I carved the ribs for the wingtips out of 1″ insulation foam. Fitted in place, the wingtip fits really nice on the end of the wing.

 

I then moved to the aft fixed metal rib. I already knew that I wanted to install these ribs “backwards” from the plans, creating a smooth flush fairing between the aileron and the wingtip.

The problem I see with this is that the rib will  interfere with the nutplate reinforcement strip that will be installed later. The top and bottom of the rib are shown below. You can see the drilled screwholes in the wingtip.

 

I decided to cut the metal rib back to where it will not interfere with the nutplates. I still get the aerodynamic smoothing I want, and I don’t believe I’ll lose any structural integrity.

I located where the rib will go in relation to the wing skins, and marked the screw holes. The location of the cut line nearly matches the aft edges of the upper and lower skins.

 

I cut the flanges of the rib, then drew a cut line on the web of the rib to allow for a bend for stiffening. I cut the rib, and bent and trimmed the material for the stiffener. Here’s a before and after; the original rib vs. my version:

Here’s the rib temporarily placed in the wingtip:

Time: 2:25

Leave a Reply

Your email address will not be published. Required fields are marked *