topeak-mtx-tortec-expeditionrack-adapter.scad

   1 // -*- C -*-
   2
   3 // brk_*: "bracket", the Topeak MTX bracket
   4 // rack_*: the Tortec rack
   5 // adapt_*: the adapter, ie this file
   6
   7 brk_recess_actual = 5.20;
   8
   9 rack_rail_dia = 10.40 + 0.50;
  10 rack_width_inner = 115.86 + 1.0; // between insides of rails
  11
  12 rear_elevation_nominal = 10.04; // top of rack to bottom of bracket
  13 rear_to_front_distance = 230;
  14
  15 general_gap_y = 1.0;
  16
  17 main_sz_y = 20;
  18 grasp_sz = 12;
  19
  20 // calculated
  21
  22 brk_bottom_y = -brk_recess_actual;
  23 adapt_main_top_y = brk_bottom_y + general_gap_y;
  24
  25 // on LHS, so -ve
  26 rack_rail_x = -(rack_width_inner + rack_rail_dia/2);
  27 rack_rail_outer_x = -(rack_width_inner + rack_rail_dia);
  28
  29 grasp_large_r = (rack_rail_dia + grasp_sz)/2;
  30 grasp_large_x = rack_rail_outer_x + grasp_large_r;
  31
  32 module Principal(){
  33   // calculated
  34   $rack_rail_y = brk_bottom_y - $elevation_nominal
  35     - general_gap_y  - rack_rail_dia/2;
  36
  37   hull(){
  38     translate([ grasp_large_x, adapt_main_top_y - grasp_large_r ])
  39       circle(grasp_large_r);
  40
  41     translate([ grasp_large_x, $rack_rail_y - rack_rail_dia/2 ])
  42       circle(grasp_large_r);
  43   }
  44 }
  45
  46 Principal($elevation_nominal=0);