brompton-computer-guard.scad

   1 // -*- C -*-
   2
   3 cover_ysz = 45;
   4 cover_len = 70;
   5
   6 attach_tube_dia = 18;
   7
   8 attach_cx = -15;
   9 attach_cdy = -5;
  10 attach_w = 25;
  11
  12 attach_inrad = 25; ///
  13 attach_hole_dist = 5; ///
  14 attach_hole_dia = 4 + 0.5; ///
  15 attach_ang = 45;
  16
  17 // calculated
  18
  19 cover_lcircle_r = cover_ysz / (1 + 1/sqrt(2));
  20
  21 base_len = cover_len - cover_lcircle_r;
  22
  23 attach_straight_len =
  24   attach_inrad + attach_tube_dia + attach_hole_dist + attach_hole_dia/2
  25   - attach_w / 2 + attach_hole_dist;
  26
  27 attach_down = tube_dia + attach_hole_dist;
  28
  29 module RearSideTemplate(){
  30   polygon([[0.1,0],
  31            [-base_len,0],
  32            [-base_len,-cover_ysz],
  33            [0.1,      -cover_ysz]]);
  34   translate([-base_len, -cover_ysz + cover_lcircle_r])
  35     circle(r=cover_lcircle_r);
  36 }
  37
  38 module AttachTemplate(){
  39   hull(){
  40     polygon([[0,   0],
  41              [-0.1, 0],
  42              [-0.1, -cover_ysz],
  43              [0,    -cover_ysz]]);
  44     translate([attach_cx, -attach_cdy]) rotate([0,0,-attach_ang]) {
  45       polygon([[-attach_cx,          attach_w/2],
  46                [0,                   -attach_w/2],
  47                [attach_straight_len, -attach_w/2],
  48                [attach_straight_len, attach_w/2]]);
  49       translate([attach_straight_len, 0])
  50         circle(r=attach_w/2);
  51     }
  52   }
  53 }
  54
  55 module BodyPositive(){
  56   color("blue") linear_extrude(height=60) RearSideTemplate();
  57   translate([0,0,-attach_down]) linear_extrude(height=100) AttachTemplate();
  58 }
  59
  60 module Tube(){
  61   %translate([attach_cx, -attach_cdy, -20]) {
  62     rotate_extrude(convexity=10) {
  63       translate([attach_inrad + attach_tube_dia/2, 0])
  64         circle(r=attach_tube_dia/2);
  65     }
  66   }
  67 }
  68
  69 module Bolt(){
  70   %translate([0,0,-50]) linear_extrude(height=80) {
  71     circle(r=attach_hole_dia/2, $fn=20);
  72   }
  73   %translate([0,0,10]) linear_extrude(height=20) {
  74     circle(r=attach_hole_dia/2 * 2, $fn=20);
  75   }
  76 }
  77
  78 module Bolts(){
  79   translate([attach_cx, -attach_cdy]) rotate([0,0,-attach_ang]) {
  80     translate([attach_inrad - attach_hole_dist - attach_hole_dia/2, 0])
  81       Bolt();
  82     translate([attach_inrad + attach_tube_dia
  83                +attach_hole_dist + attach_hole_dia/2, 0])
  84       Bolt();
  85   }
  86 }
  87
  88 Tube();
  89 Bolts();
  90 BodyPositive();