5 screwrad = 4.5 / 2 + fudge; // xxx check
6 shaftrad = 7.5 / 2 - fudge;
8 diskrad = 12.0 / 2 - fudge;
12 shaftlen = 8; // xxx check
20 disktaperrad = diskrad - diskthick / disktaperratio;
21 totallen = shaftlen + diskthick;
24 polygon([[-screwrad, 0],
26 [-diskrad, -diskthick],
27 [-shaftrad, -diskthick],
28 [-shaftrad, -totallen],
29 [-screwrad, -totallen]]);
33 rotate_extrude($fn=25, convexity=3){