Brett and I did a test of a folding wing glider
I got it at Walmart for something like 10 bucks (end of summer sale).
It flew poorly. We could not get it to pitch up. It comes all ready to fly. I can see that they designed some wing reflex into it but perhaps because of flat packaging it wasn’t enough. I bent some more into it. It helped a bit but it still couldn’t raise the nose.
The construction methods are interesting. Very robust with the use of a fabric like wing surface and injection molded parts. Too heavy for rubber-power at this scale but just right for a toy catapult glider. Also the hinged folding wing worked fairly well.
There is a traditional type of folding wing glider concept by Jim Walker. I added the patent pictures below. They have a DIY/kit over at make that I’d like to try. Bill Kuhl also has done some recent experiments.
I feel that there is a lot of complexity in the traditional design. So when I took a stab at catapult gliders not too long ago. I decided to not do a complex folding wing but instead try a spinning maple seed type descent. As it turns out, a spinning maple seed doesn’t work as well when you scale it up. They work but they don’t have the beauty since the efficiency seems to drop off. This is an awesome marvel of nature.