pulley.scad

   1 infty = 100;
   2 eps = 0.01;
   3
   4 diameter = 25;
   5 thick = 2.5;
   6 base_thick = 1.5;
   7 d_minus = thick; // cca 45 deg
   8
   9 center_hole_d = 3.5;
  10 side_holes = 5;
  11 side_hole_d = 5;
  12
  13 cut_hole_d = 2;
  14 cut_slot = 1;
  15
  16 module body() {
  17         cylinder(r1 = diameter/2, r2 = diameter/2-d_minus/2, h = thick/2 + eps);
  18         translate([0, 0, thick/2-eps])
  19                 cylinder(r2 = diameter/2, r1 = diameter/2-d_minus/2, h = thick/2 + eps);
  20 }
  21
  22 difference() {
  23         body($fn = 128);
  24         translate([0, 0, -eps])
  25                 cylinder(r = center_hole_d/2, h = thick + 2*eps, $fn = 128);
  26         if (side_holes > 0)
  27         for (angle = [0:360/side_holes:360]) rotate([0, 0, angle+180/side_holes])
  28                 translate([diameter/3 - d_minus + center_hole_d/2, 0, -eps])
  29                         cylinder(r = side_hole_d/2, h = thick + 2*eps, $fn=128);
  30         if (base_thick)
  31                 difference() {
  32                         translate([0, 0, base_thick])
  33                                 cylinder(
  34                                         r1 = center_hole_d/2 + base_thick,
  35                                         r2 = diameter/2-d_minus/2,
  36                                         h = thick-base_thick+eps, $fn = 128);
  37                         translate([0, 0, base_thick-eps])
  38                                 cylinder(r1 = center_hole_d/2 + base_thick,
  39                                         r2 = center_hole_d/2 + base_thick/2,
  40                                         h = thick - base_thick + eps, $fn = 128);
  41                 }
  42         if (cut_hole_d) {
  43                 translate([diameter/3-cut_hole_d/2, 0, -eps])
  44                         cylinder(r = cut_hole_d/2, h = thick + 2*eps, $fn =128);
  45                 translate([diameter/2-d_minus/2, -cut_slot/2, -eps])
  46                         cube([diameter/2, cut_slot, thick + 2*eps]);
  47         }
  48 }