Maple Seed (non-functional so far)

Darn. I thought these would work right away if I copied the geometry of a real maple seed. I must be missing some critical detail, because all my test prints are dropping like bricks.
Any suggestions? I tried a few sizes ranging from 2.5" long (roughly life size) down to about 1" long.
I was hoping to use these on a bigger post tomorrow, but I might need to resort to a more standard propeller geometry.