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_head = 10; // xxx
  14 screw_nut_across = 10; // xxx
  15 screw_nut_th = 5; // xxx
  16 screw_head_h = 5; // xxx
  17
  18 knob_behind_across = 15; // xxx
  19 behind_knob_th = 5;
  20
  21 clamp_width = 20;
  22
  23 clamp_gap = 2;
  24
  25 lower_th = 1;
  26
  27 overlap_l = 0.1;
  28
  29 bridge_slop_factor = 1.5;
  30
  31 $fs = 0.1;
  32 $fa = 5;
  33
  34 // calculated
  35
  36 main_r = tube_dia/2 + main_th;
  37
  38 hinge_outer_r = hinge_around + hinge_pin/2;
  39 hinge_y = tube_dia/2 + hinge_outer_r;
  40
  41 screw_max_y_lhs = -main_r -screw_nut_across/2;
  42 screw_max_y_rhs = -main_r -knob_behind_across/2;
  43
  44 screw_y = min(screw_max_y_lhs,
  45               screw_max_y_rhs);
  46
  47 bot_y = screw_y -max( screw_nut_across, knob_behind_across/2 )
  48   -minor_wall_min;
  49
  50 echo(bot_y);
  51
  52 module TubePlan(){ circle(r = tube_dia/2); }
  53 module HingePinPlan(){ translate([0, hinge_y]) circle(r= hinge_pin/2); }
  54 module HingeBodyPlan(){ translate([0, hinge_y]) circle(r= hinge_outer_r); }
  55
  56 module TubeClampLeftPlan(){
  57   difference(){
  58     union(){
  59       polygon([[ 0,                    hinge_y + hinge_outer_r ],
  60                [ -main_r + overlap_l,  hinge_y + hinge_outer_r ],
  61                [ -main_r + overlap_l,  bot_y                   ],
  62                [ -clamp_gap/2,         bot_y                   ],
  63                [ -clamp_gap/2,         0,                      ],
  64                [ 0,                    0,                      ],
  65                ]);
  66       HingeBodyPlan();
  67     }
  68     TubePlan();
  69     HingePinPlan();
  70   }
  71 }
  72
  73 module TubeClampLeft() { ////toplevel
  74   linextr(-clamp_width/2, clamp_width/2)
  75     TubeClampLeftPlan();
  76 }
  77
  78 module TubeClampRightPlan(){
  79   difference(){
  80     union(){
  81       rectfromto([ clamp_gap/2,                   bot_y ],
  82                  [ clamp_gap/2 + behind_knob_th,  0     ]);
  83       intersection(){
  84         circle(r= main_r);
  85         union(){
  86           rectfromto([0,0],
  87                       main_r *  [5,5]);
  88           rectfromto([ clamp_gap/2, main_r*5 ],
  89                       main_r * [2,-5]);
  90         }
  91       }
  92       HingeBodyPlan();
  93     }
  94     TubePlan();
  95     HingePinPlan();
  96   }
  97 }
  98
  99 module SomeClamp(){
 100   difference(){
 101     linextr(-clamp_width/2, clamp_width/2)
 102       children(0);
 103
 104     linextr_x_yz(-main_r*5, main_r*5)
 105       translate([screw_y, 0])
 106       circle(r= screw/2);
 107   }
 108 }
 109
 110 module TubeClampLeft() { ////toplevel
 111   difference(){
 112     SomeClamp()
 113       TubeClampLeftPlan();
 114
 115     translate([0, screw_y, 0]) {
 116       linextr_x_yz(-(clamp_gap/2 + screw_nut_th), 0)
 117         square([screw_nut_across, screw_nut_across * bridge_slop_factor],
 118                center=true);
 119
 120       linextr_x_yz(-main_r, -main_r + screw_head_h)
 121         square([screw_head, screw_head * bridge_slop_factor],
 122                center=true);
 123     }
 124   }
 125 }
 126
 127 module TubeClampRight() { ////toplevel
 128   SomeClamp()
 129     TubeClampRightPlan();
 130 }
 131
 132 //TubeClampLeft();
 133 //TubeClampRight();
 134