powerbank-bike-clamp.scad

   1 // -*- C -*-
   2
   3 include <utils.scad>
   4
   5 tube_dia = 22.4;
   6
   7 hinge_around = 2.5;
   8 hinge_pin = 1.5; // xxx
   9 main_th = 3;
  10 minor_wall_min = 1;
  11
  12 screw = 5.0 + 0.75;
  13 screw_nut_across = 10; // xxx
  14 knob_behind_across = 15; // xxx
  15
  16 clamp_width = 15;
  17
  18 clamp_gap = 2;
  19
  20 lower_th = 1;
  21
  22 overlap_l = 0.1;
  23
  24 // calculated
  25
  26 main_r = tube_dia/2 + main_th;
  27
  28 hinge_outer_r = hinge_around + hinge_pin/2;
  29 hinge_y = tube_dia/2 + hinge_outer_r;
  30
  31 screw_max_y_lhs = -main_r -screw_nut_across/2;
  32 screw_max_y_rhs = -main_r -knob_behind_across/2;
  33
  34 screw_y = min(screw_max_y_lhs,
  35               screw_max_y_rhs);
  36
  37 bot_y = screw_y -max( screw_nut_across, knob_behind_across/2 )
  38   -minor_wall_min;
  39
  40 echo(bot_y);
  41
  42 module TubePlan(){ circle(r = tube_dia/2); }
  43 module HingePinPlan(){ translate([0, hinge_y]) circle(r= hinge_pin/2); }
  44 module HingeBodyPlan(){ translate([0, hinge_y]) circle(r= hinge_outer_r); }
  45
  46 module TubeClampLeftPlan(){
  47   difference(){
  48     union(){
  49       polygon([[ 0,                    hinge_y + hinge_outer_r ],
  50                [ -main_r + overlap_l,  hinge_y + hinge_outer_r ],
  51                [ -main_r + overlap_l,  bot_y                   ],
  52                [ -clamp_gap/2,         bot_y                   ],
  53                [ -clamp_gap/2,         0,                      ],
  54                [ 0,                    0,                      ],
  55                ]);
  56       HingeBodyPlan();
  57     }
  58     TubePlan();
  59     HingePinPlan();
  60   }
  61 }
  62
  63 module TubeClampLeft() { ////toplevel
  64   linextr(-clamp_width/2, clamp_width/2)
  65     TubeClampLeftPlan();
  66 }
  67
  68 TubeClampLeft();
  69