All parametric Helix, Propeller, Blade Generator. Propeller for planes, helicopters, boats and others. Any size, any number of blades. New version, now with optional tip on the blade. The tip avoid loss of low pressure and turbulence in the edge of the blade. You can help me to do more things like this. Buy my designs at pinshape:http://pinshape.com/users/27920-jsirgado The OpenSCAD file is there, you can change all.I have create and uploaded some examples. For all STL samples I made a normal (NR) and a mirror (MR) version of the same helix. You will need it for quadcopters and things like it. In the samples the blades have a small cut in the top/bottom edges, just to make easy the print process. Use support material for better printing.