+// todo
+// various registration marks
+// protrustions at ends at strap width and middle
+// grooves on top face at 1/4,1/2,3/4 length and 1/2 width
+
+strap_thick = 3;
+strap_width = 26.75 + 0.7;
+
+jig_interval = 25;
+
+edgewall_width = 3;
+crewpunch_slop = 0.3;
+main_slop = 0.25;
+
+holder_min_wall = 2;
+holder_attach_near_wall = 5;
+
+holder_attach_xsz = 5;
+holder_ctie_width = 4.0 + 0.5;
+holder_ctie_thick = 3.0 + 0.5;
+holder_attach_walls = 3;
+holder_attach_roof = 2.5;
+
+holder_corner_round = 2.0;
+
+punch_travel = 8;
+
+// from careful measurement
+
+crewpunch_shape =
+ [[ 6, [0.6, 6.0], [1.6, 12.3] ],
+ [ 8, [1.1, 6.2], [1.9, 12.5] ],
+ [ 10, [1.6, 6.5], [2.1, 12.8] ],
+ [ 12, [1.8, 6.6], [2.3, 12.7] ],
+ [ 14, [2.1, 6.8], [2.6, 13.0] ],
+ [ 16, [2.4, 6.9], [2.7, 13.2] ],
+ [ 18, [2.5, 7.0], [2.9, 13.3] ],
+ [ 22, [3.1, 7.1], [3.2, 13.4] ],
+ [ 26, [3.3, 7.2], [3.5, 13.6] ],
+ ];
+
+crewpunch_shaft_max_y = 7.5;
+
+crewpunch_systematic_size_error = +0.36;
+
+crewpunch_smallest_shape = crewpunch_shape[0];
+crewpunch_biggest_shape = crewpunch_shape[len(crewpunch_shape)-1];
+
+crewpunch_skew_angle = 3.5; //degrees
+crewpunch_skew_yoff = +1.1; //mm
+
+// computed
+
+punch_dx = 0.5 * (-crewpunch_biggest_shape[2][0]
+ +crewpunch_biggest_shape[2][1]);
+punch_dy = 0.5 * (+crewpunch_biggest_shape[1][1]
+ -crewpunch_biggest_shape[1][0]) + crewpunch_skew_yoff;
+
+attach_ysz = holder_attach_walls*2 + holder_ctie_width;
+
+holder_block_zsz = crewpunch_biggest_shape[0] - crewpunch_smallest_shape[0];
+holder_xsz = crewpunch_biggest_shape[2][0] + crewpunch_biggest_shape[2][1] +
+ holder_min_wall*2;
+
+holder_skewangle_yextra = holder_xsz/2 * sin(abs(crewpunch_skew_angle));
+
+holder_max_y = punch_dy + crewpunch_biggest_shape[1][0] + holder_min_wall
+ + crewpunch_systematic_size_error + holder_skewangle_yextra;
+
+holder_attach_max_y = punch_dy
+ - max(crewpunch_biggest_shape[1][1], crewpunch_shaft_max_y)
+ - crewpunch_systematic_size_error - holder_skewangle_yextra;
+
+holder_block_min_y = punch_dy
+ - crewpunch_biggest_shape[1][1] - holder_attach_near_wall +
+ - crewpunch_systematic_size_error - holder_skewangle_yextra;
+
+holder_all_min_y = holder_attach_max_y - attach_ysz;
+
+jig_max_y = max(holder_max_y + main_slop, strap_width/2) + edgewall_width;
+jig_min_y = min(holder_all_min_y - main_slop, -strap_width/2) - edgewall_width;
+
+jig_main_zsz = holder_block_zsz + punch_travel;
+
+// common stuff
+
+include <belt-cut-jig-common.scad>
+
+// objects
+