trailerhubcap.scad

   1 maindia = 28.4;
   2 poleholeh = 5.0;
   3 polecovth = 0.4;
   4 poleholerad = 6;
   5
   6 mainoverlap = 1.5;
   7
   8 hookbasew = 4;
   9 hookfullw = 6;
  10 hookheight = 4;
  11 hookwidth = 5;
  12
  13 fingernaildepth = 5;
  14 fingernailheight = 2.5;
  15 fingernailwidth = 6;
  16
  17 bigrad = maindia/2 + mainoverlap;
  18 mainth = poleholeh + polecovth;
  19 hooklessdepth = hookfullw - hookbasew;
  20
  21 module base() {
  22   rotate_extrude(convexity=10)
  23     mirror([1,0,0])
  24     polygon(points=[[-bigrad, 0],
  25                     [-bigrad + mainth, -mainth],
  26                     [0, -mainth],
  27                     [0, -poleholeh],
  28                     [-poleholerad, -poleholeh],
  29                     [-poleholerad, 0]]);
  30 }
  31
  32 module fingernails() {
  33   for (ang=[60,180,300])
  34     rotate([0,0,ang])
  35       translate([bigrad - fingernaildepth,
  36                  -fingernailwidth/2,
  37                  -fingernailheight])
  38       cube([fingernaildepth + 1, fingernailwidth, fingernailheight + 1]);
  39 }
  40
  41 module hookrim() {
  42   rotate_extrude(convexity=10)
  43     mirror([1,0,0])
  44     translate([-maindia/2, 0, 0])
  45     polygon(points=[[hooklessdepth, 0],
  46                     [hookfullw, 0],
  47                     [hookfullw, hookheight],
  48                     [0, hookheight],
  49                     [0, hooklessdepth]]);
  50 }
  51
  52 module hooktriangles() {
  53   for (ang=[0,120,240]) {
  54     rotate([0,0,ang]) {
  55       translate([0,0,-1]) {
  56         linear_extrude(height=hookheight+2) {
  57           polygon(points=[[0, 0],
  58                           [maindia/2 + 1, -hookwidth],
  59                           [maindia/2 + 1, +hookwidth]]);
  60         }
  61       }
  62     }
  63   }
  64 }
  65
  66 difference(){
  67   base();
  68   fingernails();
  69 }
  70 intersection(){
  71   hookrim();
  72   hooktriangles();
  73 }