Trapezoid Screw Thread Module: Extrude-Transform Polygons

thingiverse

JelleAtProtospace pointed out that trapezoid screw thread are useful as well, e.g. to make a drivenut for the leadscrew threaded rods used in many CNC machines. http://en.wikipedia.org/wiki/Trapezoidal_thread_forms That sounded like a valuable and fairly simple modification, but I wasn't looking forward to modifying the polyhedron command at the heart of the module (adding each new vertex means adding several triangles and making sure they have the right winding order), but like anything else, you get used to it with practice and it really wasn't that bad. It allows you to generate trapezoid screw threads that follow any set of equations you care to provide them, some of which will have more practical application that others. Some of these even look like they might make serviceable springs. Again, because it generates the triangles directly via the polyhedron command, it's fast and lightweight. Instructions This is actually pretty clean code, feel free to take a look. Also, since it compiles fast, experiments are easy! GitHub repository: github.com/syvwlch/Thingiverse-Projects/tree/master/ExtrudePolygon If there is enough interest, I could make a library version?