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Forward rib fluting question

georgemohr

Well Known Member
Hi 14'ers!

I've been fluting the forward ribs based on the "tabletop" then "straight edge" approaches, and I think I'm getting good results. However the ribs with a cutout for the stiffeners exhibit something I'm unsure of.

You can see from the difference in image 1 and 2 below that the aft upper portion of the rib seem to "cog" between these two orientations. It doesn't take much force to alight the fore and aft sections into a line, but the rib really doesn't want to sit that way by itself.

The fluting activity doesn't make this tendency better, in fact it probably worsens it a bit. But as you can sorta see from the edge shot below, I'm getting the rivet holes lined up nicely.

So am I ok, or missing something?

TY!
G
 

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You are OK, from my experience these need the most fluting around the nose of it and be aware that putting them in place dry require more fiddling. Once you coat them with proseal on the flange, it acts as lubricant and they go into place easier.

Good luck
 
You are OK, from my experience these need the most fluting around the nose of it and be aware that putting them in place dry require more fiddling. Once you coat them with proseal on the flange, it acts as lubricant and they go into place easier.

Good luck
 
Fluting

Hole alignment is what matters. Flute in small increments only where needed to get holes aligned to the skin. Checknoften. Note. Not all skin holes are in a perfect line.
 
No, you’re not missing anything. As long as the fore row of rivets are straight in line and the aft row are straight in line the slight joggle will be a non issue when you cleco the rib in place. Don’t forget to check that flanges are square to entire web depth. You can check this by laying rib on flat surface with flanges up and use a small machinist square. Or use a big enough square to span entire web depth.
 
I found the easiest way was to use an 18 in stainless ruler that is thin enough to bend around the ribs. Once the holes are all in line, your good.
 
Thanks for all the feedback. I'm happy with the hole straightness using the flexible ruler method so I'm going to press on! I suspect this cogging is a side effect of the stiffening embossments in the rib web, coupled with the large cutout in the flange for the stiffener pass through.
 
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