pin-hinge.scad

   1 // -*- C -*-
   2
   3 $hinge_pin_dia = 0.795 + 0.35;
   4 $hinge_main_dia = 4.0;
   5 $hinge_inter_gap = 0.50;
   6 $hinge_prong_minwidth = 3.5;
   7 $hinge_noncrit_gap = 1.0;
   8
   9 $fa = 3;
  10 $fs = 0.05;
  11
  12 module HingePinPlan(){
  13   circle(r= $hinge_pin_dia/2);
  14 }
  15
  16 module HingeProngPlan(behind){
  17   hull(){
  18     circle(r= $hinge_main_dia/2);
  19     polygon([[0,0],
  20              [-$hinge_main_dia/2, -behind],
  21              [+$hinge_main_dia/2, -behind]]);
  22   }
  23 }
  24
  25 module HingeGapPlan() {
  26   circle(r = $hinge_main_dia/2 + $hinge_inter_gap);
  27 }
  28
  29 module PlanDemo(){
  30   HingeProngPlan(5);
  31   %HingeGapPlan();
  32   translate([0,0,1]) color("red") HingePinPlan();
  33 }
  34
  35 module HingePositive(l){
  36   linetr_x_yz(0, l)
  37     HingeProngPlan();
  38 }
  39
  40 module HingeNegative(l){
  41   eff_l = l + $hionge_inter_gap;
  42   pairs = floor(eff_l / (2*($hinge_prong_minwidth + $hinge_inter_gap)));
  43   stride = eff_l / pairs;
  44   prong_width = stride/2 - $hinge_inter_gap;
  45   linextr_x_ayz(-0.1, l+0.1)
  46     HingePinPlan();
  47   for (i=[0:pairs-1]) {
  48     translate(stride * i * [1,0,0])
  49       linextr_x_yz(0, prong_width + $hinge_inter_gap)
  50       HingeGapPlan();
  51   }
  52 }
  53
  54 PlanDemo();