belt-slot-cut-jig.scad

   1 // -*- C -*-
   2
   3 // todo
   4 //  various registration marks
   5 //   protrustions at ends at strap width and middle
   6 //   grooves on top face at 1/4,1/2,3/4 length and 1/2 width
   7
   8 crewpunch_slop = 0.3;
   9
  10 holder_min_wall = 2;
  11 holder_attach_near_wall = 5;
  12
  13 holder_attach_xsz = 5;
  14 holder_ctie_width = 4.0 + 0.5;
  15 holder_ctie_thick = 3.0 + 0.5;
  16 holder_attach_walls = 3;
  17 holder_attach_roof = 2.5;
  18
  19 jig_interval = 25;
  20 strap_width = 26.75 + 0.7;
  21 strap_thick = 3;
  22 edgewall_width = 3;
  23
  24 punch_travel = 8;
  25
  26 main_slop = 0.5;
  27
  28 jig_max_len = 160; // print diagonally
  29 //jig_max_len = 30;
  30
  31 registrationgroove_width = 0.8;
  32 registrationgroove_depth = 1.2;
  33
  34 registrationprotrusion_poke = 3;
  35 registrationprotrusion_slope = 0.75;
  36
  37 jig_overlap = 1;
  38
  39 // from careful measurement
  40
  41 crewpunch_shape =
  42   [[  6, [0.6, 6.0], [1.6, 12.3] ],
  43    [  8, [1.1, 6.2], [1.9, 12.5] ],
  44    [ 10, [1.6, 6.5], [2.1, 12.8] ],
  45    [ 12, [1.8, 6.6], [2.3, 12.7] ],
  46    [ 14, [2.1, 6.8], [2.6, 13.0] ],
  47    [ 16, [2.4, 6.9], [2.7, 13.2] ],
  48    [ 18, [2.5, 7.0], [2.9, 13.3] ],
  49    [ 22, [3.1, 7.1], [3.2, 13.4] ],
  50    [ 26, [3.3, 7.2], [3.5, 13.6] ],
  51    ];
  52
  53 crewpunch_shaft_max_y = 7.5;
  54
  55 crewpunch_systematic_size_error = +0.36;
  56
  57 crewpunch_smallest_shape = crewpunch_shape[0];
  58 crewpunch_biggest_shape = crewpunch_shape[len(crewpunch_shape)-1];
  59
  60 crewpunch_skew_angle = 3.5; //degrees
  61 crewpunch_skew_yoff = +1.1; //mm
  62
  63 // computed
  64
  65 punch_dx = 0.5 * (-crewpunch_biggest_shape[2][0]
  66                   +crewpunch_biggest_shape[2][1]);
  67 punch_dy = 0.5 * (+crewpunch_biggest_shape[1][1]
  68                   -crewpunch_biggest_shape[1][0]) + crewpunch_skew_yoff;
  69
  70 attach_ysz = holder_attach_walls*2 + holder_ctie_width;
  71
  72 holder_block_zsz = crewpunch_biggest_shape[0] - crewpunch_smallest_shape[0];
  73 holder_xsz = crewpunch_biggest_shape[2][0] + crewpunch_biggest_shape[2][1] +
  74   holder_min_wall*2;
  75
  76 holder_skewangle_yextra = holder_xsz/2 * sin(abs(crewpunch_skew_angle));
  77
  78 holder_max_y = punch_dy + crewpunch_biggest_shape[1][0] + holder_min_wall
  79   + crewpunch_systematic_size_error + holder_skewangle_yextra;
  80
  81 holder_attach_max_y = punch_dy
  82   - max(crewpunch_biggest_shape[1][1], crewpunch_shaft_max_y)
  83   - crewpunch_systematic_size_error - holder_skewangle_yextra;
  84
  85 holder_block_min_y = punch_dy
  86   - crewpunch_biggest_shape[1][1] - holder_attach_near_wall +
  87   - crewpunch_systematic_size_error - holder_skewangle_yextra;
  88
  89 holder_all_min_y = holder_attach_max_y - attach_ysz;
  90
  91 jig_max_y = max(holder_max_y + main_slop, strap_width/2) + edgewall_width;
  92 jig_min_y = min(holder_all_min_y - main_slop, -strap_width/2) - edgewall_width;
  93
  94 jig_main_zsz = holder_block_zsz + punch_travel;
  95
  96 jig_ends_extra = 2;
  97
  98 //jig_iters = (jig_max_len - jig_ends_extra) / jig_interval;
  99 jig_iters=2;
 100 echo(jig_iters);
 101
 102 // objects
 103
 104 module CrewPunch(){
 105   ourslop = crewpunch_slop - crewpunch_systematic_size_error;
 106   hull(){
 107     for(layer=crewpunch_shape){
 108       translate([0,0, layer[0]]){
 109         for(xind=[0,1]) //translate([xind?0:1,0,0])
 110           for(yind=[0,1]) //translate([0,yind?0.5:0,0])
 111             mirror([xind?1:0,0,0]) mirror([0,yind?0:1,0]){
 112               translate([-0.1,-0.1,-0.1])
 113                 cube([0.1 + layer[2][xind] + ourslop,
 114                       0.1 + layer[1][1-yind] + ourslop,
 115                       0.2]);
 116             }
 117       }
 118     }
 119   }
 120 }
 121
 122 module MaybeRoundedCube(sizes, roundedness){
 123   if (roundedness > 0) {
 124     translate([roundedness, roundedness, 0]){
 125       minkowski(){
 126         cube([sizes[0] - roundedness*2,
 127               sizes[1] - roundedness*2,
 128               sizes[2]]);
 129         cylinder(h=0.05, r=roundedness, $fn=20);
 130       }
 131     }
 132   } else {
 133     cube(sizes);
 134   }
 135 }
 136
 137 module PunchHolder(cutouts=true){
 138     difference(){
 139       translate([-holder_xsz/2, holder_block_min_y, 0])
 140         cube([holder_xsz,
 141               holder_max_y - holder_block_min_y,
 142               holder_block_zsz]);
 143       if (cutouts)
 144         rotate([0,0,-crewpunch_skew_angle])
 145         translate([punch_dx,
 146                    punch_dy,
 147                    -crewpunch_smallest_shape[0]])
 148           CrewPunch();
 149     }
 150     difference(){
 151       translate([-holder_attach_xsz/2, holder_all_min_y, 0])
 152         cube([holder_attach_xsz,
 153               attach_ysz,
 154               holder_block_zsz + punch_travel
 155               + holder_ctie_thick + holder_attach_roof + 1]);
 156       if (cutouts)
 157         translate([-30,
 158                    holder_all_min_y + holder_attach_walls,
 159                    holder_block_zsz + punch_travel])
 160           cube([60, holder_ctie_width, holder_ctie_thick]);
 161     }
 162 }
 163
 164 module RegistrationGroove(l){
 165   // runs along the +ve X axis for length l but at correct z pos
 166   translate([0, 0, jig_main_zsz + 0.1]) {
 167     rotate([90,0,90])
 168       linear_extrude(height=l)
 169       polygon([[-registrationgroove_width/2, 0],
 170                [ +registrationgroove_width/2, 0],
 171                [ 0, -registrationgroove_depth ]]);
 172   }
 173 }
 174
 175 module OneJig(){
 176   difference(){
 177     translate([-(jig_interval/2 + jig_overlap),
 178                jig_min_y,
 179                -strap_thick])
 180       cube([jig_interval + 2,
 181             jig_max_y - jig_min_y,
 182             jig_main_zsz + strap_thick]);
 183     minkowski(){
 184       cube([main_slop*2, main_slop*2, 50], center=true);
 185       PunchHolder(false);
 186     }
 187     translate([-100, -strap_width/2, -10])
 188       cube([200, strap_width, 10]);
 189    translate([-100,0,0])
 190      RegistrationGroove(200);
 191    for (xfrac=[-1/4,0,+1/4])
 192      translate([jig_interval * xfrac, -100, 0])
 193        rotate([0,0,90])
 194        RegistrationGroove(200);
 195   }
 196 }
 197
 198 module RegistrationProtrusion(){
 199   // points towards the positive x axis
 200   xsz = registrationprotrusion_poke;
 201   ysz = registrationprotrusion_poke;
 202   diag_sz = xsz * sqrt(2);
 203   zsz = diag_sz / registrationprotrusion_slope;
 204   hull(){
 205     translate([0, 0, 0.1]){
 206       linear_extrude(height=0.1)
 207         polygon([[   0, -ysz ],
 208                  [ xsz,    0 ],
 209                  [   0,  ysz ]]);
 210       translate([-0.1, 0, zsz ])
 211         rotate([0,0,45])
 212         cube(0.1);
 213     }
 214   }
 215 }
 216
 217 module Jig(){
 218   for(end=[0,1]){
 219     for(yfrac=[-1/2, 0, 1/2]){
 220       translate([ end
 221                   ? jig_interval * (jig_iters - 0.5)
 222                   : -jig_interval/2,
 223                  yfrac * strap_width,
 224                  0])
 225         rotate([0,0, end ? 0 : 180])
 226         translate([ jig_overlap, 0, 0 ])
 227         RegistrationProtrusion();
 228     }
 229   }
 230   for (i=[0:jig_iters-1]) {
 231     translate([jig_interval * i, 0, 0])
 232       OneJig();
 233   }
 234 }
 235
 236 module JigT(){ ////toplevel
 237   rotate([0,0,-45])
 238     translate([0,0,jig_main_zsz])
 239     rotate([180,0,0])
 240     Jig();
 241 }
 242
 243 module PunchHolderT(){ ////toplevel
 244   PunchHolder(true);
 245 }
 246
 247 module Demo(){ ////toplevel
 248   %PunchHolder();
 249   Jig();
 250 }
 251
 252 module Kit(){ ////toplevel
 253   JigT();
 254   rotate([0,0,-45]){
 255     translate([(jig_iters-1)*jig_interval/2,
 256                jig_min_y - holder_max_y - 5,
 257                0])
 258       PunchHolder();
 259   }
 260 }
 261
 262 //CrewPunch();
 263 //PunchHolder();
 264 //PunchHolder(false);
 265 //OneJig();
 266 //Jig();
 267 //Demo();
 268 //JigT();
 269 //RegistrationProtrusion();
 270 //PunchHolderT();
 271 //Kit();