Wing tip questions

[Charles in SC]

I am trying to start on my tips. I cut styro ribs to put inside but after moving them around to various places I cannot seem to get all the dips and such pushed out at the same time. Has anyone ever tried putting a long square piece of styro (maybe 2x2) lengthwise on the top and bottom in the tip and glassing over them to make individual ribs kind of like a bass bar in a guitar or fiddle? I am just trying to make them look right not reinvent the wheel.
Thanks in advance!

 

[D-Dubya]

I think there are some builders that have installed fiberglass stiffeners inside the wingtips, but most will leave them as is. Yes, the tips get somewhat deformed in shipping and seem to take a "set", but it typically works out after a while. And once you get them attached to the wing, they seem to fall into the proper shape.

If you haven't already, place the tips with the open end down (tips up) so that they're not laying on the curved surface. Check after a few weeks and see if the bumps and humps have smoothed out all on their own.

 

[Rick_A]

I did something similar to your lengthwise idea. I used some light weight rope as a form rather then foam as the "core". I think the glass is that part that really adds the strength. I may have even removed the rope after the glass set.

In order to make sure that you get the shape of the tip right when you do this, my suggestion is to cleco the tip to the wing while the glass stringer is curing. I did it with my wing upside down on a bench.

 

[dhall_polo]

heat?

If you're just dealing with an issue of the tips being a bit flat from having been packed up and such, then this can be resolved with a hair dryer or heat gun. Just heat up the glass a little and hold it in a shape that's around where you want it to be while it cools down.

For my -7, the wingtips needed very little work. I think they all come a little too long, so you have to sand them back a bit to line up with the ailerons. The best time to install the wingtip rib is when you've aligned the flaps and ailerons to neutral position.