OpenScad Geometry

This is a simple library of OpenSCAD modules.
There isn't really an object here (although if you want a funnel...)

- Ring creates a tube (hollow cylinder)
- Hollow Cone is like ring but a cone.
- Funnel is a customizable funnel
- Knurled knob is a cylinder with removed cylinders
- Line is just a long narrow cube but if you do a lot of lines it's easier to read
- Domed cylinder is actually useless but I might find some use