Verwendet "BOSL" für die Schraube und 
aus github "openscad-extra/src /torus.scad" und “openscad-extra/src /wedge.scad”.

include <BOSL/constants.scad>;
use <torus.scad>;
use <wedge.scad>;
use <BOSL/transforms.scad>
use <BOSL/beziers.scad>
use <BOSL/math.scad>
use <BOSL/metric_screws.scad>;