Wingtips move, hinge method

[clam]

I also ground the tip of the pin into a point to help it make the turns and not hang up on eyelet borders.

[Outflyn]

I also used the hinge method to attach my wing tips on my -9A, but I also added small "L" brackets to the tip rib and the aileron bracket and added a bolt between them to prevent the wing tips from moving. It has worked well and I have no movement of the tips.

My build log is on the EAA Builders site: https://eaabuilderslog.org/?blproject&proj=7ZLY3oI53

Photos showing how I did the tips are under the Left Wing subfolder Left Tip entry: https://eaabuilderslog.org/?blprojec...cat=^left_wing

Not sure if you’ll be able to see the picture I’m trying to put here, if not hopefully the link will work.

https://eaabuilderslog.org/showmy.ph...f=IMG_9768.JPG

For the finial assembly I used a drilled bolt head and safety wired it to the bracket. The bolt is easily accessed in the gap area between the tip and the aileron.

[Traash]

Same problem here. My fix works well. Made a strap to connect the wing to the tip. Riveted to wing, screwed to tip.

[Traash]

Pictures added for clarity.

[SeanB]

Thanks guys! I was also having similar thoughts to mechanically stop top movement. Your ideas and pics are very helpful! I appreciate it.

[toolmanmike]

Guys, what is the purpose of the hinges in the wing tips? Why not nut plates and screws? Etc. Im not there yet, but am looking for good mods before I reach that phase.

[wirejock]

Originally Posted by toolmanmike

Guys, what is the purpose of the hinges in the wing tips? Why not nut plates and screws? Etc. Im not there yet, but am looking for good mods before I reach that phase.

Makes R&R fast and easy. Just pull the pin.
I have a "how to", draft article on my blog.
https://wirejockrv7a.blogspot.com/p/wing-tips.html

[Stevea]

Originally Posted by wirejock

Makes R&R fast and easy. Just pull the pin.

OK, granted it may be slightly faster than me spinning out 45 #6 screws per wingtip using an electric drill.

OTOH, think I've had the wingtips off maybe 3 times since first flight. Once for paint, second time for a landing light upgrade, and third time to pull a new temp probe wire through the conduit. Other than needing to get in for landing/strobe/nav light access, there's no reason to pull the tips for any maintenance related job......at least on my airplane. Yours may be different.

Interestingly, the screws/nutplates addition to the wingtips is itself a change to the original plans. The 3/4/6 plans call for flush 1/8" pop rivets on the wingtips. Not sure about the later models.

Next time you see a T-34, take a look at the spar to leading edge connection. Held on with hinges and pins.....probably thicker hinges with larger pins than the ones being used for RV wingtips, but still pinned together. So, it does work to hold relatively important things together on a wing.

[erich weaver]

I agree with above post. This mod is just not worth it. Wing tips very rarely come off and when they do it’s a very quick job with power screwdriver.

[Bavafa]

Originally Posted by erich weaver

I agree with above post. This mod is just not worth it. Wing tips very rarely come off and when they do it’s a very quick job with power screwdriver.

I agree that if the primary motivation is faster removal/installation, then this mod is not worth the effort. I have done the standard way and my latest plane has the hinge method. I did it primarily for the looks and I lucked out as mine has no movement.