Wingtips move, hinge method

SeanB · #1 06-21-2022, 07:30 AM

Hello All,

I’ve just concluded installing the wingtips using the piano hinge method. Very happy with the results and was able to get the trailing edges to align with neutral ailerons. Used ProSeal under the hinges before riveting, and e-glass to cover the rivet heads. Added stiffeners. Had to modify the aft rib some to miss the hinges, which I’ve seen done by others.

Kinda disappointed though. If I grab the aft part of the tips and wiggle up and down, there is slight play in each. Maybe 1/4” or so. I’m guessing this is play in the hinge. Anyone else have this issue? When at rest, the tips are still aligned with the ailerons. In flight??? Could raise some. Wondering if this could cause heavy wing, and over time cause wear in the hinges.

Any ideas, feedback, suggestions are appreciated.

Thanks!

Bavafa · #2 06-21-2022, 09:23 AM

I think most folks report some movement but don't think 1/4" as that seems excessive.
I have done mine and one side is rock solid and the other side has about 1/16 or slightly more but the pin slides in easier on the side that has movement. Wingtip has been known to have little to no affect on wing heavy so that is not going to be an issue. And I believe if the movement is not in such a way that each time the plane flys, the wingtips rocks up/down then this is not going to be an issue long term.

SeanB · #3 06-21-2022, 09:43 AM

Thanks, Mehrdad. I appreciate your reply.

wirejock · #4 06-21-2022, 10:00 AM

How far forward did you install the hinges? Could that cause it? Mine are pretty solid. Hinge goes almost to the tip. I have to use a drill to get the pins in.

SeanB · #5 06-21-2022, 10:54 AM

Hi Larry. Interesting thought. I do not have the hinges all the way forward. Could be a factor, as you describe. Pictures I’ve seen from prior builders seemed to leave a portion of fiberglass on the leading edge, then start hinges aft.

Bavafa · #6 06-21-2022, 11:23 AM

Quote:

Originally Posted by SeanB

Hi Larry. Interesting thought. I do not have the hinges all the way forward. Could be a factor, as you describe. Pictures I’ve seen from prior builders seemed to leave a portion of fiberglass on the leading edge, then start hinges aft.

Sean,
Mine are also go forward just as the photos or possibly a little more. I believe only one rivet hole on top was installed without the hinge which I put a dummy rivet.

clam · #7 06-21-2022, 11:35 AM

This is the answer. It will secure the wingtip.

Quote:

Originally Posted by wirejock

How far forward did you install the hinges? Could that cause it? Mine are pretty solid. Hinge goes almost to the tip. I have to use a drill to get the pins in.

SeanB · #8 06-21-2022, 11:50 AM

Thanks for the replies, everyone. I did just use the standard pre-drilled holes of the aluminum skin to determine length. Wondering if I could add a bit more hinge material (4-5 eyelets) forward of the existing. Will have to be very careful with alignment or I imagine getting pins in will be difficult.

wirejock · #9 06-21-2022, 04:55 PM

Quote:

Originally Posted by SeanB

Hi Larry. Interesting thought. I do not have the hinges all the way forward. Could be a factor, as you describe. Pictures I’ve seen from prior builders seemed to leave a portion of fiberglass on the leading edge, then start hinges aft.

Mine are almost exactly like the photos. It's a bit of work to get the pins all the way in but they don't move.

wcalvert · #10 06-21-2022, 05:55 PM

Sean. The tips on my plane are mounted just like yours and move a little (maybe 1/8") at the trailing edge on the ground. My hinge goes forward enough that the last bit of hinge pin can be difficult, but they go in. I may have used a drill motor when doing the final install to help drive them home.

180 hours of happy flying with all sorts of maneuvering and they show no signs of wear or getting looser. So that's good.

Cheers