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 behind_knob_th = 5;
  16
  17 clamp_width = 15;
  18
  19 clamp_gap = 2;
  20
  21 lower_th = 1;
  22
  23 overlap_l = 0.1;
  24
  25 // calculated
  26
  27 main_r = tube_dia/2 + main_th;
  28
  29 hinge_outer_r = hinge_around + hinge_pin/2;
  30 hinge_y = tube_dia/2 + hinge_outer_r;
  31
  32 screw_max_y_lhs = -main_r -screw_nut_across/2;
  33 screw_max_y_rhs = -main_r -knob_behind_across/2;
  34
  35 screw_y = min(screw_max_y_lhs,
  36               screw_max_y_rhs);
  37
  38 bot_y = screw_y -max( screw_nut_across, knob_behind_across/2 )
  39   -minor_wall_min;
  40
  41 echo(bot_y);
  42
  43 module TubePlan(){ circle(r = tube_dia/2); }
  44 module HingePinPlan(){ translate([0, hinge_y]) circle(r= hinge_pin/2); }
  45 module HingeBodyPlan(){ translate([0, hinge_y]) circle(r= hinge_outer_r); }
  46
  47 module TubeClampLeftPlan(){
  48   difference(){
  49     union(){
  50       polygon([[ 0,                    hinge_y + hinge_outer_r ],
  51                [ -main_r + overlap_l,  hinge_y + hinge_outer_r ],
  52                [ -main_r + overlap_l,  bot_y                   ],
  53                [ -clamp_gap/2,         bot_y                   ],
  54                [ -clamp_gap/2,         0,                      ],
  55                [ 0,                    0,                      ],
  56                ]);
  57       HingeBodyPlan();
  58     }
  59     TubePlan();
  60     HingePinPlan();
  61   }
  62 }
  63
  64 module TubeClampLeft() { ////toplevel
  65   linextr(-clamp_width/2, clamp_width/2)
  66     TubeClampLeftPlan();
  67 }
  68
  69 module TubeClampRightPlan(){
  70   difference(){
  71     union(){
  72       rectfromto([ clamp_gap/2,                   bot_y ],
  73                  [ clamp_gap/2 + behind_knob_th,  0     ]);
  74       intersection(){
  75         circle(r= main_r);
  76         union(){
  77           rectfromto([0,0],
  78                       main_r *  [5,5]);
  79           rectfromto([ clamp_gap/2, main_r*5 ],
  80                       main_r * [2,-5]);
  81         }
  82       }
  83       HingeBodyPlan();
  84     }
  85     TubePlan();
  86     HingePinPlan();
  87   }
  88 }
  89
  90 module SomeClamp(){
  91   difference(){
  92     linextr(-clamp_width/2, clamp_width/2)
  93       children(0);
  94
  95     linextr_x_yz(-main_r*5, main_r*5)
  96       translate([screw_y, 0])
  97       circle(r= screw/2);
  98   }
  99 }
 100
 101 module TubeClampLeft() { ////toplevel
 102   SomeClamp()
 103     TubeClampLeftPlan();
 104 }
 105
 106 module TubeClampRight() { ////toplevel
 107   SomeClamp()
 108     TubeClampRightPlan();
 109 }
 110
 111 //TubeClampLeft();
 112 TubeClampRight();
 113