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 bank_recess_y = 5;
  43 bank_recess_dx = 3;
  44
  45 strap_th = 3;
  46 strap_above = 2.5;
  47
  48 // calculated
  49
  50 pspt_to_mm = 25.4 / 72;
  51
  52 hinge_stride = (clamp_width + hinge_gap_z) / hinge_lobes;
  53
  54 main_r = tube_dia/2 + main_th;
  55
  56 hinge_outer_r = hinge_around + hinge_pin/2;
  57 hinge_y = tube_dia/2 + hinge_outer_r;
  58
  59 screw_max_y_lhs = -main_r -screw_nut_across/2;
  60 screw_max_y_rhs = -main_r -knob_behind_across/2;
  61
  62 screw_y = min(screw_max_y_lhs,
  63               screw_max_y_rhs);
  64
  65 bot_y = screw_y -max( screw_nut_across, knob_behind_across/2 )
  66   -minor_wall_min;
  67
  68 echo(bot_y);
  69
  70 module TubePlan(){ circle(r = tube_dia/2); }
  71 module HingePinPlan(){ translate([0, hinge_y]) circle(r= hinge_pin/2); }
  72 module HingeBodyPlan(){ translate([0, hinge_y]) circle(r= hinge_outer_r); }
  73
  74 module TubeClampLeftPlan(){
  75   difference(){
  76     union(){
  77       polygon([[ 0,                    hinge_y + hinge_outer_r ],
  78                [ -main_r + overlap_l,  hinge_y + hinge_outer_r ],
  79                [ -main_r + overlap_l,  bot_y                   ],
  80                [ -clamp_gap/2,         bot_y                   ],
  81                [ -clamp_gap/2,         0,                      ],
  82                [ 0,                    0,                      ],
  83                ]);
  84       HingeBodyPlan();
  85     }
  86     TubePlan();
  87     HingePinPlan();
  88   }
  89 }
  90
  91 module TubeClampLeft() { ////toplevel
  92   linextr(-clamp_width/2, clamp_width/2)
  93     TubeClampLeftPlan();
  94 }
  95
  96 module TubeClampRightPlan(){
  97   difference(){
  98     union(){
  99       rectfromto([ clamp_gap/2,                   bot_y ],
 100                  [ clamp_gap/2 + behind_knob_th,  0     ]);
 101       intersection(){
 102         circle(r= main_r);
 103         union(){
 104           rectfromto([0,0],
 105                       main_r *  [5,5]);
 106           rectfromto([ clamp_gap/2, main_r*5 ],
 107                       main_r * [2,-5]);
 108         }
 109       }
 110       HingeBodyPlan();
 111     }
 112     TubePlan();
 113     HingePinPlan();
 114   }
 115 }
 116
 117 module SomeClamp(hinge_alt=false){
 118   difference(){
 119     linextr(-clamp_width/2, clamp_width/2)
 120       children(0);
 121
 122     linextr_x_yz(-main_r*5, main_r*5)
 123       translate([screw_y, 0])
 124       circle(r= screw/2);
 125
 126     for (i=[0 : hinge_lobes-1]) {
 127       translate([0,
 128                  hinge_y,
 129                  -clamp_width/2 + i * hinge_stride
 130                  + (hinge_alt ? hinge_stride/2 : 0)
 131                  ])
 132         linextr(-hinge_gap_z, hinge_stride/2)
 133         square(hinge_outer_r*2 + hinge_gap_xy, center=true);
 134     }
 135   }
 136 }
 137
 138 module PowerBankSidePlan(){ ////toplevel
 139   render() difference(){
 140     rectfromto([ -(bank_x_sz/2 + bank_recess_dx),  -(strap_above + strap_th) ],
 141                [ +(bank_x_sz/2 + bank_recess_dx),  bank_recess_y ]);
 142
 143     scale( bank_x_sz / ( (
 144                           bank_eps_bbox_x[1] -
 145                           bank_eps_bbox_x[0]
 146                          ) * pspt_to_mm ))
 147       translate(pspt_to_mm *
 148                 [-0.5 * (bank_eps_bbox_x[0] +
 149                          bank_eps_bbox_x[1]),
 150                  -bank_eps_bbox_y[0]])
 151       import("powerbank-anker-10000.dxf", convexity=5);
 152   }
 153 }
 154
 155 module PowerBankHolder(){ ////toplevel
 156
 157 }
 158
 159 module TubeClampLeft() { ////toplevel
 160   difference(){
 161     SomeClamp(true)
 162       TubeClampLeftPlan();
 163
 164     translate([0, screw_y, 0]) {
 165       linextr_x_yz(-(clamp_gap/2 + screw_nut_th), 0)
 166         square([screw_nut_across,
 167                 screw_nut_across / cos(30) + bridge_slop*2],
 168                center=true);
 169
 170       linextr_x_yz(-main_r, -main_r + screw_head_h)
 171         square([screw_head, screw_head + bridge_slop*2],
 172                center=true);
 173     }
 174   }
 175 }
 176
 177 module TubeClampRight() { ////toplevel
 178   rotate([180,0,0])
 179     SomeClamp()
 180     TubeClampRightPlan();
 181 }
 182
 183 module TubeClampDemo() { ////toplevel
 184   TubeClampLeft();
 185   rotate([180,0,0])
 186     TubeClampRight();
 187 }