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
  17 knob_behind_across = 12.2 + 0.75;
  18 behind_knob_th = 5;
  19
  20 clamp_min_width = 20;
  21
  22 clamp_gap = 2;
  23
  24 lower_th = 1;
  25
  26 overlap_l = 0.1;
  27
  28 bridge_slop = 1.2;
  29
  30 hinge_lobe_per = 10;
  31 hinge_gap_z = 0.75;
  32 hinge_gap_xy = 0.75;
  33
  34 $fs = 0.1;
  35 $fa = 5;
  36
  37 bank_eps_bbox_x = [149, 598];
  38 bank_eps_bbox_y = [274, 1452];
  39
  40 bank_y_sz = 102.25 + 0.50 + 3.2;
  41 bank_x_sz = (26.0 + 0.5);
  42 bank_recess_y = 5;
  43
  44 strap_th = 3;
  45 strap_above = 2.5;
  46
  47 retainer_walls = [18, 30];
  48
  49 bank_profile_scale_bodge = 1.0;
  50
  51 bank_input_ctr = [ 12.5, 11.5 ]; // from nearest corner
  52 bank_input_sz  = [ 8.5, 10.5 ];
  53
  54 mounted_pos_y_offset = 20;
  55
  56 liner_th = 0.8;
  57
  58 brace_r = 5;
  59 brace_len = 50;
  60
  61 // calculated
  62
  63 straps_y = [ -bank_y_sz * 0.25,
  64              +bank_y_sz * 0.25 ];
  65
  66 screw_head_behind = main_th;
  67 endwall_th = main_th;
  68
  69 bank_recess_dx = minor_wall_min;
  70
  71 pspt_to_mm = 25.4 / 72;
  72
  73 main_r = tube_dia/2 + main_th;
  74
  75 screw_max_y_lhs = -main_r -screw_nut_across/2;
  76 screw_max_y_rhs = -main_r -knob_behind_across/2;
  77
  78 screw_y = min(screw_max_y_lhs,
  79               screw_max_y_rhs);
  80
  81 bot_y = screw_y -max( screw_nut_across, knob_behind_across/2 )
  82   -minor_wall_min;
  83
  84 holder_x_sz = bank_x_sz + bank_recess_dx*2;
  85 bank_bot_y = strap_above + strap_th;
  86 strap_r = strap_th;
  87
  88 brace_total_len = brace_len + main_th;
  89 brace_ctrs_y = [ straps_y[0] - (brace_r + strap_r/2),
  90                  straps_y[1] + (brace_r + strap_r/2) ];
  91
  92 clamp_width_actual = max(clamp_min_width, holder_x_sz);
  93
  94 hinge_lobes = floor(clamp_width_actual / hinge_lobe_per);
  95 hinge_stride = (clamp_width_actual + hinge_gap_z) / hinge_lobes;
  96
  97 hinge_outer_r = hinge_around + hinge_pin/2;
  98 hinge_y = tube_dia/2 + hinge_outer_r;
  99
 100 echo(bot_y);
 101
 102 module TubePlan(){ circle(r = tube_dia/2); }
 103 module HingePinPlan(){ translate([0, hinge_y]) circle(r= hinge_pin/2); }
 104 module HingeBodyPlan(){ translate([0, hinge_y]) circle(r= hinge_outer_r); }
 105
 106 module TubeClampLeftPlan(){
 107   difference(){
 108     union(){
 109       polygon([[ 0,                      hinge_y + hinge_outer_r ],
 110                [ -(main_r + overlap_l),  hinge_y + hinge_outer_r ],
 111                [ -(main_r + overlap_l),  bot_y                   ],
 112                [ -clamp_gap/2,           bot_y                   ],
 113                [ -clamp_gap/2,           0,                      ],
 114                [ 0,                      0,                      ],
 115                ]);
 116       HingeBodyPlan();
 117     }
 118     TubePlan();
 119     HingePinPlan();
 120   }
 121 }
 122
 123 module TubeClampLeft() { ////toplevel
 124   linextr(-clamp_width_actual/2, clamp_width_actual/2)
 125     TubeClampLeftPlan();
 126 }
 127
 128 module TubeClampRightPlan(){
 129   difference(){
 130     union(){
 131       rectfromto([ clamp_gap/2,                   bot_y ],
 132                  [ clamp_gap/2 + behind_knob_th,  0     ]);
 133       intersection(){
 134         circle(r= main_r);
 135         union(){
 136           rectfromto([0,0],
 137                       main_r *  [5,5]);
 138           rectfromto([ clamp_gap/2, main_r*5 ],
 139                       main_r * [2,-5]);
 140         }
 141       }
 142       HingeBodyPlan();
 143     }
 144     TubePlan();
 145     HingePinPlan();
 146   }
 147 }
 148
 149 module Screws(){
 150   linextr_x_yz(-main_r*5, main_r*5)
 151     translate([screw_y, 0])
 152     circle(r= screw/2);
 153
 154   translate([0, screw_y, 0]) {
 155     linextr_x_yz(-(clamp_gap/2 + screw_nut_th), 0)
 156       square([screw_nut_across,
 157               screw_nut_across / cos(30) + bridge_slop*2],
 158              center=true);
 159
 160     linextr_x_yz(-200,
 161                  -(clamp_gap/2 + screw_nut_th + screw_head_behind))
 162       square([screw_head, screw_head + bridge_slop*2],
 163              center=true);
 164   }
 165 }
 166
 167 module SomeClamp(hinge_alt=false){
 168   difference(){
 169     linextr(-clamp_width_actual/2, clamp_width_actual/2)
 170       children(0);
 171
 172     Screws();
 173
 174     for (i=[0 : hinge_lobes-1]) {
 175       translate([0,
 176                  hinge_y,
 177                  -clamp_width_actual/2 + i * hinge_stride
 178                  + (hinge_alt ? hinge_stride/2 : 0)
 179                  ])
 180         linextr(-hinge_gap_z, hinge_stride/2)
 181         square(hinge_outer_r*2 + hinge_gap_xy, center=true);
 182     }
 183   }
 184 }
 185
 186 module PowerBankItselfSidePlan(){
 187   translate([0, bank_bot_y]){
 188     minkowski(){
 189       circle($fn=8, r=liner_th);
 190       scale( bank_profile_scale_bodge *
 191              bank_x_sz / ( (
 192                             bank_eps_bbox_x[1] -
 193                             bank_eps_bbox_x[0]
 194                             ) * pspt_to_mm ))
 195         translate(pspt_to_mm *
 196                   [-0.5 * (bank_eps_bbox_x[0] +
 197                            bank_eps_bbox_x[1]),
 198                    -bank_eps_bbox_y[0]])
 199         import("powerbank-anker-10000.dxf", convexity=5);
 200     }
 201   }
 202 }
 203
 204 module PowerBankItself(){ ////toplevel
 205   rotate([0,90,0])
 206     linextr_y_xz(-bank_y_sz/2,
 207                  +bank_y_sz/2)
 208     PowerBankItselfSidePlan();
 209 }
 210
 211 module PowerBankSidePlan(){ ////toplevel
 212   render() difference(){
 213     rectfromto([ -holder_x_sz/2,  0 ],
 214                [ +holder_x_sz/2,  bank_recess_y + bank_bot_y ]);
 215
 216     PowerBankItselfSidePlan();
 217   }
 218 }
 219
 220 module PowerBankStrapCut(){ ////toplevel
 221   difference(){
 222     rectfromto([ -holder_x_sz, -0.05 ],
 223                [ +holder_x_sz, strap_th + strap_r ]);
 224     hull(){
 225       for (sx=[-1,+1]) {
 226         translate([sx * (holder_x_sz/2 - strap_r + 0.1),
 227                    strap_th + strap_r])
 228           circle(strap_r);
 229       }
 230     }
 231   }
 232 }
 233
 234 module PowerBankHolderTest(){ ////toplevel
 235   difference(){
 236     linextr(-1,5) PowerBankSidePlan();
 237     linextr(0, strap_th) PowerBankStrapCut();
 238   }
 239 }
 240
 241 module EndRetainer(depth){ ////toplevel
 242   translate([0, -bank_y_sz/2, 0]) {
 243     linextr_y_xz(-endwall_th, 0)
 244     rectfromto([ 0,         -holder_x_sz/2 ],
 245                [ -depth,    +holder_x_sz/2 ]);
 246
 247     for (m=[0,1]) {
 248       mirror([0,0,m]) {
 249         linextr(-holder_x_sz/2, -bank_x_sz/2){
 250           hull(){
 251             rectfromto([ 0, -endwall_th ],
 252                        [ depth, 0 ]);
 253             rectfromto([ 0, 0 ],
 254                        [ 0.1, depth-0.1 ]);
 255           }
 256         }
 257       }
 258     }
 259   }
 260 }
 261
 262 module BraceTubePlan(){
 263   intersection(){
 264     circle(r= brace_r);
 265     rectfromto(brace_r * [-2,  0],
 266                brace_r * [+2, +2]);
 267   }
 268 }
 269
 270 module PowerBankHolder(){ ////toplevel
 271   difference(){
 272     union(){
 273       rotate([0,90,0])
 274         linextr_y_xz(-(bank_y_sz/2 + 0.1),
 275                      +(bank_y_sz/2 + 0.1))
 276         PowerBankSidePlan();
 277
 278       EndRetainer(retainer_walls[0]);
 279       mirror([0,1,0]) EndRetainer(retainer_walls[1]);
 280     }
 281
 282     for (strap_y = straps_y)
 283       translate([0, strap_y, 0])
 284         rotate([0,0,-90])
 285         rotate([0,90,0])
 286         linextr(-strap_th/2,
 287                 +strap_th/2)
 288         PowerBankStrapCut();
 289
 290     translate([ bank_bot_y, -bank_y_sz/2, -bank_x_sz/2 ])
 291       linextr_y_xz(-50,50)
 292        rotate([0,0,90])
 293        translate(bank_input_ctr)
 294        square(center=true, bank_input_sz);
 295   }
 296
 297   translate([0,0, bank_x_sz/2]){
 298     for (y = brace_ctrs_y) {
 299       translate([0,y,0]) {
 300         linextr_x_yz(0, brace_total_len)
 301           BraceTubePlan();
 302       }
 303     }
 304     translate([brace_total_len, 0,0])
 305       linextr_y_xz(brace_ctrs_y[0] - brace_r,
 306                    brace_ctrs_y[1] + brace_r)
 307       BraceTubePlan();
 308   }
 309 }
 310
 311 module TubeClampLeft() { ////toplevel
 312   // We want this to print with the recess overhand to the right
 313   // where the workpiece cooling fan is
 314   rotate([0,0,180]){
 315     difference(){
 316       SomeClamp(true)
 317         TubeClampLeftPlan();
 318
 319       Screws();
 320     }
 321   }
 322 }
 323
 324 module PlacePowerBank(){
 325   translate([main_r, -mounted_pos_y_offset, 0])
 326     children(0);
 327 }
 328
 329 module Main(){ ////toplevel
 330   TubeClampLeft();
 331   difference(){
 332     PlacePowerBank()
 333       PowerBankHolder();
 334     rotate([0,0,180])
 335       Screws();
 336   }
 337 }
 338
 339 module TubeClampRight() { ////toplevel
 340   rotate([0,0,180])
 341     rotate([180,0,0])
 342     SomeClamp()
 343     TubeClampRightPlan();
 344 }
 345
 346 module TubeClampDemo() { ////toplevel
 347   TubeClampLeft();
 348   rotate([180,0,0])
 349     TubeClampRight();
 350 }
 351
 352 module Demo() { ////toplevel
 353   Main();
 354   rotate([180,0,0])
 355     TubeClampRight();
 356   PlacePowerBank()
 357     %PowerBankItself();
 358 }