About this 3D model

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.