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 = 3;
  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 = 3.5;
  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 = 2.0; //degrees
  61 crewpunch_skew_yoff = -0.6; //mm
  62
  63 // computed
  64
  65 attach_ysz = holder_attach_walls*2 + holder_ctie_width;
  66
  67 holder_block_zsz = crewpunch_biggest_shape[0] - crewpunch_smallest_shape[0];
  68 holder_xsz = crewpunch_biggest_shape[2][0] + crewpunch_biggest_shape[2][1] +
  69   holder_min_wall*2;
  70
  71 holder_front_all = crewpunch_shaft_max_y - crewpunch_biggest_shape[1][0]
  72   + attach_ysz + crewpunch_systematic_size_error + crewpunch_skew_yoff
  73   + holder_xsz/2 * sin(abs(crewpunch_skew_angle));
  74
  75 crewpunch_biggest_y =
  76   crewpunch_biggest_shape[1][0] + crewpunch_biggest_shape[1][1];
  77 holder_ysz = crewpunch_biggest_y + holder_min_wall + holder_front_all;
  78
  79 attach_offset = 0.5 * (holder_front_all - holder_attach_near_wall);
  80
  81 jig_main_zsz = holder_block_zsz + punch_travel;
  82
  83 jig_ends_extra = 2;
  84
  85 //jig_iters = (jig_max_len - jig_ends_extra) / jig_interval;
  86 jig_iters=2;
  87 echo(jig_iters);
  88
  89 // objects
  90
  91 module CrewPunch(){
  92   ourslop = crewpunch_slop - crewpunch_systematic_size_error;
  93   hull(){
  94     for(layer=crewpunch_shape){
  95       translate([0,0, layer[0]]){
  96         for(xind=[0,1]) //translate([xind?0:1,0,0])
  97           for(yind=[0,1]) //translate([0,yind?0.5:0,0])
  98             mirror([xind?1:0,0,0]) mirror([0,yind?0:1,0]){
  99               translate([-0.1,-0.1,-0.1])
 100                 cube([0.1 + layer[2][xind] + ourslop,
 101                       0.1 + layer[1][1-yind] + ourslop,
 102                       0.2]);
 103             }
 104       }
 105     }
 106   }
 107 }
 108
 109 module PunchHolder(cutouts=true){
 110   translations=[-holder_xsz/2,
 111                 -holder_ysz + holder_min_wall + crewpunch_biggest_y/2,
 112                 0];
 113   translate(translations){
 114     difference(){
 115       translate([0,attach_offset,0])
 116         cube([holder_xsz, holder_ysz - attach_offset, holder_block_zsz]);
 117       if (cutouts)
 118         translate([0,-crewpunch_skew_yoff])
 119         translate(-translations)
 120         rotate([0,0,-crewpunch_skew_angle])
 121         translate(translations)
 122         translate([crewpunch_biggest_shape[2][1] + holder_min_wall,
 123                    crewpunch_biggest_shape[1][1] + holder_front_all,
 124                    -crewpunch_smallest_shape[0]])
 125           CrewPunch();
 126     }
 127     difference(){
 128       translate([holder_xsz/2 - holder_attach_xsz/2, 0, 0])
 129         cube([holder_attach_xsz,
 130               attach_ysz,
 131               holder_block_zsz + punch_travel
 132               + holder_ctie_thick + holder_attach_roof + 1]);
 133       if (cutouts)
 134         translate([-30,
 135                    holder_attach_walls,
 136                    holder_block_zsz + punch_travel])
 137           cube([60, holder_ctie_width, holder_ctie_thick]);
 138     }
 139   }
 140 }
 141
 142 module RegistrationGroove(l){
 143   // runs along the +ve X axis for length l but at correct z pos
 144   translate([0, 0, jig_main_zsz + 0.1]) {
 145     rotate([90,0,90])
 146       linear_extrude(height=l)
 147       polygon([[-registrationgroove_width/2, 0],
 148                [ +registrationgroove_width/2, 0],
 149                [ 0, -registrationgroove_depth ]]);
 150   }
 151 }
 152
 153 module OneJig(){
 154   difference(){
 155     translate([-(jig_interval/2 + jig_overlap),
 156                -(strap_width/2 + edgewall_width) - attach_offset,
 157                -strap_thick])
 158       cube([jig_interval + 2,
 159             strap_width + edgewall_width*2 + attach_offset,
 160             jig_main_zsz + strap_thick]);
 161     minkowski(){
 162       cube([main_slop*2, main_slop*2, 50], center=true);
 163       PunchHolder(false);
 164     }
 165     translate([-100, -strap_width/2, -10])
 166       cube([200, strap_width, 10]);
 167    translate([-100,0,0])
 168      RegistrationGroove(200);
 169    for (xfrac=[-1/4,0,+1/4])
 170      translate([jig_interval * xfrac, -100, 0])
 171        rotate([0,0,90])
 172        RegistrationGroove(200);
 173   }
 174 }
 175
 176 module RegistrationProtrusion(){
 177   // points towards the positive x axis
 178   xsz = registrationprotrusion_poke;
 179   ysz = registrationprotrusion_poke;
 180   diag_sz = xsz * sqrt(2);
 181   zsz = diag_sz / registrationprotrusion_slope;
 182   hull(){
 183     translate([0, 0, 0.1]){
 184       linear_extrude(height=0.1)
 185         polygon([[   0, -ysz ],
 186                  [ xsz,    0 ],
 187                  [   0,  ysz ]]);
 188       translate([-0.1, 0, zsz ])
 189         rotate([0,0,45])
 190         cube(0.1);
 191     }
 192   }
 193 }
 194
 195 module Jig(){
 196   for(end=[0,1]){
 197     for(yfrac=[-1/2, 0, 1/2]){
 198       translate([ end
 199                   ? jig_interval * (jig_iters - 0.5)
 200                   : -jig_interval/2,
 201                  yfrac * strap_width,
 202                  0])
 203         rotate([0,0, end ? 0 : 180])
 204         translate([ jig_overlap, 0, 0 ])
 205         RegistrationProtrusion();
 206     }
 207   }
 208   for (i=[0:jig_iters-1]) {
 209     translate([jig_interval * i, 0, 0])
 210       OneJig();
 211   }
 212 }
 213
 214 module JigT(){ ////toplevel
 215   translate([0,0,jig_main_zsz])
 216     rotate([180,0,0])
 217     Jig();
 218 }
 219
 220 module PunchHolderT(){ ////toplevel
 221   PunchHolder(true);
 222 }
 223
 224 module Demo(){ ////toplevel
 225   %PunchHolder();
 226   Jig();
 227 }
 228
 229 module Kit(){ ////toplevel
 230   rotate([0,0,-45]){
 231     JigT();
 232     translate([(jig_iters-1)*jig_interval/2,
 233                -strap_width,
 234                0])
 235       PunchHolder();
 236   }
 237 }
 238
 239 //CrewPunch();
 240 //PunchHolder();
 241 //PunchHolder(false);
 242 //OneJig();
 243 //Jig();
 244 //Demo();
 245 //JigT();
 246 //RegistrationProtrusion();
 247 //PunchHolderT();
 248 //Kit();