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 = 2.0 + 0.5;
  16 holder_attach_walls = 3;
  17 holder_attach_roof = 2.5;
  18
  19 jig_interval = 25;
  20 strap_width = 25;
  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 jig_overlap = 1;
  35
  36 // from careful measurement
  37
  38 crewpunch_shape =
  39   [[  6, [0.6, 6.0], [1.6, 12.3] ],
  40    [  8, [1.1, 6.2], [1.9, 12.5] ],
  41    [ 10, [1.6, 6.5], [2.1, 12.8] ],
  42    [ 12, [1.8, 6.6], [2.3, 12.7] ],
  43    [ 14, [2.1, 6.8], [2.6, 13.0] ],
  44    [ 16, [2.4, 6.9], [2.7, 13.2] ]];
  45
  46 crewpunch_shaft_max_y = 7.5;
  47
  48 crewpunch_systematic_size_error = +0.36;
  49
  50 crewpunch_min_y = 4.7 - crewpunch_systematic_size_error;
  51
  52 crewpunch_smallest_shape = crewpunch_shape[0];
  53 crewpunch_biggest_shape = crewpunch_shape[len(crewpunch_shape)-1];
  54
  55 // computed
  56
  57 attach_ysz = holder_attach_walls*2 + holder_ctie_width;
  58 holder_front_all = crewpunch_shaft_max_y - crewpunch_biggest_shape[1][1]
  59   + attach_ysz;
  60
  61 holder_block_zsz = crewpunch_biggest_shape[0] - crewpunch_smallest_shape[0];
  62 holder_xsz = crewpunch_biggest_shape[2][0] + crewpunch_biggest_shape[2][1] +
  63   holder_min_wall*2;
  64 crewpunch_biggest_y =
  65   crewpunch_biggest_shape[1][0] + crewpunch_biggest_shape[1][1];
  66 holder_ysz = crewpunch_biggest_y + holder_min_wall + holder_front_all;
  67
  68 attach_offset = 0.5 * (holder_front_all - holder_attach_near_wall);
  69
  70 jig_main_zsz = holder_block_zsz + punch_travel;
  71
  72 jig_ends_extra = 2;
  73
  74 //jig_iters = (jig_max_len - jig_ends_extra) / jig_interval;
  75 jig_iters=2;
  76 echo(jig_iters);
  77
  78 // objects
  79
  80 module CrewPunch(){
  81   ourslop = crewpunch_slop - crewpunch_systematic_size_error;
  82   hull(){
  83     for(layer=crewpunch_shape){
  84       translate([0,0, layer[0]]){
  85         for(xind=[0,1]) //translate([xind?0:1,0,0])
  86           for(yind=[0,1]) //translate([0,yind?0.5:0,0])
  87             mirror([xind?1:0,0,0]) mirror([0,yind?0:1,0]){
  88               translate([-0.1,-0.1,-0.1])
  89                 cube([0.1 + layer[2][xind] + ourslop,
  90                       0.1 + layer[1][yind] + ourslop,
  91                       0.2]);
  92             }
  93       }
  94     }
  95   }
  96 }
  97
  98 module PunchHolder(cutouts=true){
  99   translate([-holder_xsz/2,
 100              -holder_ysz + holder_min_wall + crewpunch_biggest_y/2,
 101              0]){
 102     difference(){
 103       translate([0,attach_offset,0])
 104         cube([holder_xsz, holder_ysz - attach_offset, holder_block_zsz]);
 105       if (cutouts)
 106         translate([crewpunch_biggest_shape[2][1] + holder_min_wall,
 107                    crewpunch_biggest_shape[1][0] + holder_front_all,
 108                    -crewpunch_smallest_shape[0]])
 109           CrewPunch();
 110     }
 111     difference(){
 112       translate([holder_xsz/2 - holder_attach_xsz/2, 0, 0])
 113         cube([holder_attach_xsz,
 114               attach_ysz,
 115               holder_block_zsz + punch_travel
 116               + holder_ctie_thick + holder_attach_roof + 1]);
 117       if (cutouts)
 118         translate([-30,
 119                    holder_attach_walls,
 120                    holder_block_zsz + punch_travel])
 121           cube([60, holder_ctie_width, holder_ctie_thick]);
 122     }
 123   }
 124 }
 125
 126 module RegistrationGroove(l){
 127   // runs along the +ve X axis for length l but at correct z pos
 128   translate([0, 0, jig_main_zsz + 0.1]) {
 129     rotate([90,0,90])
 130       linear_extrude(height=l)
 131       polygon([[-registrationgroove_width/2, 0],
 132                [ +registrationgroove_width/2, 0],
 133                [ 0, -registrationgroove_depth ]]);
 134   }
 135 }
 136
 137 module OneJig(){
 138   difference(){
 139     translate([-(jig_interval/2 + jig_overlap),
 140                -(strap_width/2 + edgewall_width) - attach_offset,
 141                -strap_thick])
 142       cube([jig_interval + 2,
 143             strap_width + edgewall_width*2 + attach_offset,
 144             jig_main_zsz + strap_thick]);
 145     minkowski(){
 146       cube([main_slop*2, main_slop*2, 50], center=true);
 147       PunchHolder(false);
 148     }
 149     translate([-100, -strap_width/2, -10])
 150       cube([200, strap_width, 10]);
 151    translate([-100,0,0])
 152      RegistrationGroove(200);
 153    for (xfrac=[-1/4,0,+1/4])
 154      translate([jig_interval * xfrac, -100, 0])
 155        rotate([0,0,90])
 156        RegistrationGroove(200);
 157   }
 158 }
 159
 160 module Jig(){
 161   for (i=[0:jig_iters-1]) {
 162     translate([jig_interval * i, 0, 0])
 163       OneJig();
 164   }
 165 }
 166
 167 module JigT(){ ////toplevel
 168   rotate([180,0,0])
 169     Jig();
 170 }
 171
 172 module PunchHolderT(){ ////toplevel
 173   PunchHolder(true);
 174 }
 175
 176 module Demo(){
 177   %PunchHolder();
 178   Jig();
 179 }
 180
 181 //CrewPunch();
 182 //PunchHolder();
 183 //PunchHolder(false);
 184 //OneJig();
 185 //Jig();
 186 //Demo();
 187 //JigT();
 188 //PunchHolderT();