Update: I went and redrew my old plans for the German DFS Habicht. I made a long wing version out of foam board
And a stub-wing version out of rubber foam.
The rubber version was cut out of two sheets of about 1/16' foam rubber from a craft store. With the sheets being letter-sized, this limited my fuselage to 10 in.
Unfortunately 1/16' is a bit thin for the wings, so the larger ones tended to bend upward and flutter at large speeds. Back in the day I had foam of 3mm thick, which worked a lot better. Still, with the small wing it is a nice though fast sailer. And you can use it indoors as it bounces back from walls, flower vases and little brothers without leaving damage. I might see if I can find some thicker foam somewhere.
The foam board version also flies remarkably well, but I used Elmer's foam board of which I had to peel off to the paper for weight reasons and found the remaining inner foam plank a bit too thin and (for the wings) a bit too easy to bend. So I had to reinforce the wing with a balsa rod. At 10 in. length and 15 in. span it's rather small. I will try again with a bigger model (20-25 in ) and see if I can use Dollar store foam board that does not need peeling.
Ps... My plans/templates for the rubber and fsfb versions:
Rubber foam....
Dollar store foam board. After some trying I gave up on the gull-wing of the original and used the two straight half-wings glued in at an angle. The one-piece wing should work for Flite-test foam board, but was too thin on the peeled Elmer board I used.