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 = 1.8 + 0.75;
   9 main_th = 3;
  10 minor_wall_min = 1;
  11
  12 screw = 5.0 + 0.75;
  13 screw_head = 8.7 + 1.2;
  14 screw_nut_across = 7.9 + 0.75;
  15 screw_nut_th = 3.9 + 0.75;
  16 screw_head_h = 3.6 + 0.75;
  17
  18 knob_behind_across = 12.2 + 0.75;
  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 = 1.2;
  30
  31 hinge_lobes = 2;
  32 hinge_gap_z = 0.75;
  33 hinge_gap_xy = 0.75;
  34
  35 $fs = 0.1;
  36 $fa = 5;
  37
  38 bank_eps_bbox_x = [149, 598];
  39 bank_eps_bbox_y = [274, 1452];
  40
  41 bank_x_sz = (24.9 + 0.5);
  42
  43 // calculated
  44
  45 hinge_stride = (clamp_width + hinge_gap_z) / hinge_lobes;
  46
  47 main_r = tube_dia/2 + main_th;
  48
  49 hinge_outer_r = hinge_around + hinge_pin/2;
  50 hinge_y = tube_dia/2 + hinge_outer_r;
  51
  52 screw_max_y_lhs = -main_r -screw_nut_across/2;
  53 screw_max_y_rhs = -main_r -knob_behind_across/2;
  54
  55 screw_y = min(screw_max_y_lhs,
  56               screw_max_y_rhs);
  57
  58 bot_y = screw_y -max( screw_nut_across, knob_behind_across/2 )
  59   -minor_wall_min;
  60
  61 echo(bot_y);
  62
  63 module TubePlan(){ circle(r = tube_dia/2); }
  64 module HingePinPlan(){ translate([0, hinge_y]) circle(r= hinge_pin/2); }
  65 module HingeBodyPlan(){ translate([0, hinge_y]) circle(r= hinge_outer_r); }
  66
  67 module TubeClampLeftPlan(){
  68   difference(){
  69     union(){
  70       polygon([[ 0,                    hinge_y + hinge_outer_r ],
  71                [ -main_r + overlap_l,  hinge_y + hinge_outer_r ],
  72                [ -main_r + overlap_l,  bot_y                   ],
  73                [ -clamp_gap/2,         bot_y                   ],
  74                [ -clamp_gap/2,         0,                      ],
  75                [ 0,                    0,                      ],
  76                ]);
  77       HingeBodyPlan();
  78     }
  79     TubePlan();
  80     HingePinPlan();
  81   }
  82 }
  83
  84 module TubeClampLeft() { ////toplevel
  85   linextr(-clamp_width/2, clamp_width/2)
  86     TubeClampLeftPlan();
  87 }
  88
  89 module TubeClampRightPlan(){
  90   difference(){
  91     union(){
  92       rectfromto([ clamp_gap/2,                   bot_y ],
  93                  [ clamp_gap/2 + behind_knob_th,  0     ]);
  94       intersection(){
  95         circle(r= main_r);
  96         union(){
  97           rectfromto([0,0],
  98                       main_r *  [5,5]);
  99           rectfromto([ clamp_gap/2, main_r*5 ],
 100                       main_r * [2,-5]);
 101         }
 102       }
 103       HingeBodyPlan();
 104     }
 105     TubePlan();
 106     HingePinPlan();
 107   }
 108 }
 109
 110 module SomeClamp(hinge_alt=false){
 111   difference(){
 112     linextr(-clamp_width/2, clamp_width/2)
 113       children(0);
 114
 115     linextr_x_yz(-main_r*5, main_r*5)
 116       translate([screw_y, 0])
 117       circle(r= screw/2);
 118
 119     for (i=[0 : hinge_lobes-1]) {
 120       translate([0,
 121                  hinge_y,
 122                  -clamp_width/2 + i * hinge_stride
 123                  + (hinge_alt ? hinge_stride/2 : 0)
 124                  ])
 125         linextr(-hinge_gap_z, hinge_stride/2)
 126         square(hinge_outer_r*2 + hinge_gap_xy, center=true);
 127     }
 128   }
 129 }
 130
 131 module PowerBankSidePlan(){ ////toplevel
 132   intersection(){
 133     scale( bank_x_sz / ( (
 134                          bank_eps_bbox_x[1] -
 135                          bank_eps_bbox_x[0]
 136                          ) / 72 * 25.4 ))
 137       translate([0, -bank_eps_bbox_y[0]])
 138       import("powerbank-anker-10000.dxf", convexity=5);
 139   }
 140 }
 141
 142 module PowerBankHolder(){ ////toplevel
 143
 144 }
 145
 146 module TubeClampLeft() { ////toplevel
 147   difference(){
 148     SomeClamp(true)
 149       TubeClampLeftPlan();
 150
 151     translate([0, screw_y, 0]) {
 152       linextr_x_yz(-(clamp_gap/2 + screw_nut_th), 0)
 153         square([screw_nut_across,
 154                 screw_nut_across / cos(30) + bridge_slop*2],
 155                center=true);
 156
 157       linextr_x_yz(-main_r, -main_r + screw_head_h)
 158         square([screw_head, screw_head + bridge_slop*2],
 159                center=true);
 160     }
 161   }
 162 }
 163
 164 module TubeClampRight() { ////toplevel
 165   rotate([180,0,0])
 166     SomeClamp()
 167     TubeClampRightPlan();
 168 }
 169
 170 module TubeClampDemo() { ////toplevel
 171   TubeClampLeft();
 172   rotate([180,0,0])
 173     TubeClampRight();
 174 }