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 pspt_to_mm = 25.4 / 72;
  46
  47 hinge_stride = (clamp_width + hinge_gap_z) / hinge_lobes;
  48
  49 main_r = tube_dia/2 + main_th;
  50
  51 hinge_outer_r = hinge_around + hinge_pin/2;
  52 hinge_y = tube_dia/2 + hinge_outer_r;
  53
  54 screw_max_y_lhs = -main_r -screw_nut_across/2;
  55 screw_max_y_rhs = -main_r -knob_behind_across/2;
  56
  57 screw_y = min(screw_max_y_lhs,
  58               screw_max_y_rhs);
  59
  60 bot_y = screw_y -max( screw_nut_across, knob_behind_across/2 )
  61   -minor_wall_min;
  62
  63 echo(bot_y);
  64
  65 module TubePlan(){ circle(r = tube_dia/2); }
  66 module HingePinPlan(){ translate([0, hinge_y]) circle(r= hinge_pin/2); }
  67 module HingeBodyPlan(){ translate([0, hinge_y]) circle(r= hinge_outer_r); }
  68
  69 module TubeClampLeftPlan(){
  70   difference(){
  71     union(){
  72       polygon([[ 0,                    hinge_y + hinge_outer_r ],
  73                [ -main_r + overlap_l,  hinge_y + hinge_outer_r ],
  74                [ -main_r + overlap_l,  bot_y                   ],
  75                [ -clamp_gap/2,         bot_y                   ],
  76                [ -clamp_gap/2,         0,                      ],
  77                [ 0,                    0,                      ],
  78                ]);
  79       HingeBodyPlan();
  80     }
  81     TubePlan();
  82     HingePinPlan();
  83   }
  84 }
  85
  86 module TubeClampLeft() { ////toplevel
  87   linextr(-clamp_width/2, clamp_width/2)
  88     TubeClampLeftPlan();
  89 }
  90
  91 module TubeClampRightPlan(){
  92   difference(){
  93     union(){
  94       rectfromto([ clamp_gap/2,                   bot_y ],
  95                  [ clamp_gap/2 + behind_knob_th,  0     ]);
  96       intersection(){
  97         circle(r= main_r);
  98         union(){
  99           rectfromto([0,0],
 100                       main_r *  [5,5]);
 101           rectfromto([ clamp_gap/2, main_r*5 ],
 102                       main_r * [2,-5]);
 103         }
 104       }
 105       HingeBodyPlan();
 106     }
 107     TubePlan();
 108     HingePinPlan();
 109   }
 110 }
 111
 112 module SomeClamp(hinge_alt=false){
 113   difference(){
 114     linextr(-clamp_width/2, clamp_width/2)
 115       children(0);
 116
 117     linextr_x_yz(-main_r*5, main_r*5)
 118       translate([screw_y, 0])
 119       circle(r= screw/2);
 120
 121     for (i=[0 : hinge_lobes-1]) {
 122       translate([0,
 123                  hinge_y,
 124                  -clamp_width/2 + i * hinge_stride
 125                  + (hinge_alt ? hinge_stride/2 : 0)
 126                  ])
 127         linextr(-hinge_gap_z, hinge_stride/2)
 128         square(hinge_outer_r*2 + hinge_gap_xy, center=true);
 129     }
 130   }
 131 }
 132
 133 module PowerBankSidePlan(){ ////toplevel
 134   intersection(){
 135     scale( bank_x_sz / ( (
 136                           bank_eps_bbox_x[1] -
 137                           bank_eps_bbox_x[0]
 138                          ) * pspt_to_mm ))
 139       translate(pspt_to_mm *
 140                 [-0.5 * (bank_eps_bbox_x[0] +
 141                          bank_eps_bbox_x[1]),
 142                  -bank_eps_bbox_y[0]])
 143       import("powerbank-anker-10000.dxf", convexity=5);
 144   }
 145 }
 146
 147 module PowerBankHolder(){ ////toplevel
 148
 149 }
 150
 151 module TubeClampLeft() { ////toplevel
 152   difference(){
 153     SomeClamp(true)
 154       TubeClampLeftPlan();
 155
 156     translate([0, screw_y, 0]) {
 157       linextr_x_yz(-(clamp_gap/2 + screw_nut_th), 0)
 158         square([screw_nut_across,
 159                 screw_nut_across / cos(30) + bridge_slop*2],
 160                center=true);
 161
 162       linextr_x_yz(-main_r, -main_r + screw_head_h)
 163         square([screw_head, screw_head + bridge_slop*2],
 164                center=true);
 165     }
 166   }
 167 }
 168
 169 module TubeClampRight() { ////toplevel
 170   rotate([180,0,0])
 171     SomeClamp()
 172     TubeClampRightPlan();
 173 }
 174
 175 module TubeClampDemo() { ////toplevel
 176   TubeClampLeft();
 177   rotate([180,0,0])
 178     TubeClampRight();
 179 }