Wingtip Nut Plates

[Utah-Jay]

Based on rivet spacing and putting nut plates between rivets, I can skip two rivets for 2 15/16” spacing or skip three rivets and go with near to 4 1/2” spacing for the nutplates/screws

I have tended to over do things, but 4+” seems like a bit too far apart

What did everyone else do?

[jaredyates]

We did the wider spacing. Not to say it's the only right way, but it worked.

[Nev]

I can't recall whether I drilled out some of the existing rivets, or did it as you describe in between the existing rivets. Here's a pic that might help.

9CCC5049-151D-438B-9DB4-961B27ED7C6D.jpg

[gregc]

I went with the wider spacing and drilled out every 4th rivet. When I have this kind of question I look at nearby certified airplanes to see how they did it.

[Mark Goldberg]

On my last project I used different spacings for the wingtip attach depending on how much the wingtip edge was pouching up between fasteners. Mark

[Battson]

If you have a lifting wingtip then you're going to want more screws to take the load. Think about the weakest point experiencing maximum g-force. I calculated it, it's a lot of force per screw. I used wide area washers to spread the force across the fibreglass.

If you have symmetrical wing tips, then as Mark says - it's really just avoiding "scalloping" which drives the spacing, that will vary depending on fit and overlap. Especially if there's a lot of overlap to the wing skin, or a poor fit.



I started with symmetrical wing tips and very few screws - but I got sick of seeing those little scallops in every photo taken out the window.... Now I have extended high lift wingtips, I have a lot of screws.

IMG_20180105_174014.jpg

IMG_20180107_202801.jpg

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[Nev]

Good idea with the wide area washers.

[alaskabearhawk]

This was talked about a few years back. I drilled out every third rivet which equaled out to 4 3/8" spacing. I fretted about this a few years back and how it looked, but after painting it looks just fine. I'm glad I didn't take the time to mess with it.

https://bearhawkforums.com/forum/bearhawk-4-place-quickbuild/56209-wingtip-fit

Wing tip.jpg