I was discussing the Zen Glider over at Reddit’s Engineering Porn forum. Zen is a walkalong glider.

A few people inquired about the materials but PinkBalloons was guessing polyethylene sheet (the Zen is actually polyurethane). It then dawned on my that I had some of that foamy fabric-like packing material lying around and it might be a good candidate. I think it might be “expanded polyethylene sheet” since when I googled just “polyethylene sheet” I got all this ultra high stuff that was very dense.

It’s not very rigid but it turns out it works great and the resulting aircraft is very resilient.

The sheet I had seemed to be 3.5mm (0.14″). I cut it into a 6″ wing and added a couple of toothpicks for ballast. I just poked the toothpicks through the fabric. That worked very well. You can just slide the toothpicks fore and aft to change the centre of gravity!

I was able to bend the wing around so it had the effect of about 1/8″ dihedral and a bit of reflex. I trimmed it to go straight by warping it around and viola.

I didn’t add any “flaps or elevons” since this material doesn’t seem to take a fold very well. I was thinking heat might work but it seemed easy enough to warp it around since it has a bit of memory.

The toothpick attachment mechanism was so cute that I think it might be worth trying to design one that is based on just one toothpick.

Related

Walkalong gliders.

Duration Competition in Ottawa

Aviation Museum Ottawa