towelbar-antislide.scad

   1 infty=200;
   2 eps=0.01;
   3
   4 bar_diam = 20;
   5 body_h = 15;
   6 body_l = 100;
   7
   8 wall = 1.5;
   9
  10 spike_w = 1;
  11 spike_l = 2;
  12
  13 module spike() {
  14         hull() {
  15                 translate([-body_h/4, 0, -eps])
  16                         cube([body_h/2, bar_diam/2+wall/2, eps]);
  17                 translate([-spike_w/2, 0, -body_h/2])
  18                         cube([spike_w, bar_diam/2 + wall + spike_l, eps]);
  19         }
  20 }
  21
  22 difference() {
  23         union() {
  24                 translate([-body_l/2, 0, 0])
  25                         rotate([0, 90, 0])
  26                                 cylinder(r = bar_diam/2 + wall, h = body_l);
  27                 for (x = [-37.5:15:37.5])
  28                         translate([x, 0, 0]) spike();
  29                 for (x = [-45:15:45])
  30                         translate([x, 0, 0]) scale([1, 1, -1]) spike();
  31         }
  32
  33         // tube hole
  34         translate([-body_l/2-eps, 0, 0])
  35                 rotate([0, 90, 0])
  36                         cylinder(r = bar_diam/2, h = body_l + 2*eps);
  37         // cut the bottom
  38         translate([-infty/2, -infty/2, -infty-body_h/2]) cube(infty);
  39         // cut the bottom
  40         translate([-infty/2, -infty/2, body_h/2]) cube(infty);
  41         // cut the bottom rear half
  42         translate([-infty/2, -infty, -infty/2]) cube(infty);
  43 }