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 = 4.8+0.5;
  10 center_hole_d2 = 2.5;
  11 side_holes = 5;
  12 side_hole_d = 5;
  13
  14 cut_hole_d = 2;
  15 cut_slot = 1;
  16
  17 module body() {
  18         cylinder(r1 = diameter/2, r2 = diameter/2-d_minus/2, h = thick/2 + eps);
  19         translate([0, 0, thick/2-eps])
  20                 cylinder(r2 = diameter/2, r1 = diameter/2-d_minus/2, h = thick/2 + eps);
  21 }
  22
  23 difference() {
  24         body($fn = 128);
  25         if (center_hole_d2 > 0) {
  26                 translate([0, 0, 0.5])
  27                         cylinder(r1 = center_hole_d/2, r2 = center_hole_d/2+0.2, h = thick + 2*eps, $fn = 8);
  28                 translate([0, 0, -eps])
  29                         cylinder(r = center_hole_d2/2, h = thick + 2*eps, $fn = 128);
  30         } else {
  31                 translate([0, 0, -eps])
  32                         cylinder(r = center_hole_d/2, h = thick + 2*eps, $fn = 128);
  33         }
  34         if (side_holes > 0)
  35         for (angle = [0:360/side_holes:360]) rotate([0, 0, angle+180/side_holes])
  36                 translate([2*diameter/7 - d_minus + center_hole_d/2, 0, -eps])
  37                         cylinder(r = side_hole_d/2, h = thick + 2*eps, $fn=128);
  38         if (base_thick)
  39                 difference() {
  40                         translate([0, 0, base_thick])
  41                                 cylinder(
  42                                         r1 = center_hole_d/2 + base_thick,
  43                                         r2 = diameter/2-d_minus/2,
  44                                         h = thick-base_thick+eps, $fn = 128);
  45                         translate([0, 0, base_thick-eps])
  46                                 cylinder(r1 = center_hole_d/2 + base_thick,
  47                                         r2 = center_hole_d/2 + base_thick/2,
  48                                         h = thick - base_thick + eps, $fn = 128);
  49                 }
  50         if (cut_hole_d) {
  51                 translate([diameter/3-cut_hole_d/2, 0, -eps])
  52                         cylinder(r = cut_hole_d/2, h = thick + 2*eps, $fn =128);
  53                 translate([diameter/2-d_minus/2, -cut_slot/2, -eps])
  54                         cube([diameter/2, cut_slot, thick + 2*eps]);
  55         }
  56 }