chiark / gitweb /
belt-slot-cut-jig: rework. crewpunch_skew_yoff now works
authorIan Jackson <ijackson@chiark.greenend.org.uk>
Fri, 14 Jun 2013 00:16:15 +0000 (01:16 +0100)
committerIan Jackson <ijackson@chiark.greenend.org.uk>
Fri, 14 Jun 2013 00:16:15 +0000 (01:16 +0100)
belt-slot-cut-jig.scad

index 8b437f5..9313b8a 100644 (file)
@@ -8,7 +8,7 @@
 crewpunch_slop = 0.3;
 
 holder_min_wall = 2;
-holder_attach_near_wall = 3;
+holder_attach_near_wall = 5;
 
 holder_attach_xsz = 5;
 holder_ctie_width = 4.0 + 0.5;
@@ -50,7 +50,7 @@ crewpunch_shape =
    [ 26, [3.3, 7.2], [3.5, 13.6] ], 
    ];
 
-crewpunch_shaft_max_y = 3.5;
+crewpunch_shaft_max_y = 7.5;
 
 crewpunch_systematic_size_error = +0.36;
 
@@ -58,11 +58,15 @@ crewpunch_smallest_shape = crewpunch_shape[0];
 crewpunch_biggest_shape = crewpunch_shape[len(crewpunch_shape)-1];
 
 crewpunch_skew_angle = 3.5; //degrees
-crewpunch_skew_yoff_broken = 0; //mm
-crewpunch_skew_yoff = -1.1; //mm
+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];
@@ -71,21 +75,21 @@ holder_xsz = crewpunch_biggest_shape[2][0] + crewpunch_biggest_shape[2][1] +
 
 holder_skewangle_yextra = holder_xsz/2 * sin(abs(crewpunch_skew_angle));
 
-holder_max_y = crewpunch_biggest_shape[1][1] + holder_min_wall
+holder_max_y = punch_dy + crewpunch_biggest_shape[1][0] + holder_min_wall
   + crewpunch_systematic_size_error + holder_skewangle_yextra;
 
-holder_block_min_y = crewpunch_biggest_shape[1][0] - holder_attach_near_wall +
+holder_attach_max_y = punch_dy
+  - max(crewpunch_biggest_shape[1][1], crewpunch_shaft_max_y)
   - crewpunch_systematic_size_error - holder_skewangle_yextra;
 
-holder_all_min_y = holder_block_min_y - attach_ysz;
-holder_front_all = abs(holder_all_min_y);
+holder_block_min_y = punch_dy
+  - crewpunch_biggest_shape[1][1] - holder_attach_near_wall +
+  - crewpunch_systematic_size_error - holder_skewangle_yextra;
 
-crewpunch_biggest_y =
-  crewpunch_biggest_shape[1][0] + crewpunch_biggest_shape[1][1];
-holder_ysz = crewpunch_biggest_y + holder_min_wall + holder_front_all
-  + max(0, -crewpunch_skew_yoff_broken);
+holder_all_min_y = holder_attach_max_y - attach_ysz;
 
-attach_offset = 0.5 * (holder_front_all - holder_attach_near_wall);
+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;
 
@@ -116,25 +120,20 @@ module CrewPunch(){
 }
 
 module PunchHolder(cutouts=true){
-  translations=[-holder_xsz/2,
-               -holder_ysz + holder_min_wall + crewpunch_biggest_y/2,
-               0];
-  translate(translations){
     difference(){
-      translate([0,attach_offset,0])
-       cube([holder_xsz, holder_ysz - attach_offset, holder_block_zsz]);
+      translate([-holder_xsz/2, holder_block_min_y, 0])
+       cube([holder_xsz,
+             holder_max_y - holder_block_min_y,
+             holder_block_zsz]);
       if (cutouts)
-       translate([0,-crewpunch_skew_yoff_broken])
-       translate(-translations)
        rotate([0,0,-crewpunch_skew_angle])
-       translate(translations)
-       translate([crewpunch_biggest_shape[2][1] + holder_min_wall,
-                  crewpunch_biggest_shape[1][1] + holder_front_all,
+       translate([punch_dx,
+                  punch_dy,
                   -crewpunch_smallest_shape[0]])
          CrewPunch();
     }
     difference(){
-      translate([holder_xsz/2 - holder_attach_xsz/2, 0, 0])
+      translate([-holder_attach_xsz/2, holder_all_min_y, 0])
        cube([holder_attach_xsz,
              attach_ysz,
              holder_block_zsz + punch_travel
@@ -145,7 +144,6 @@ module PunchHolder(cutouts=true){
                   holder_block_zsz + punch_travel])
          cube([60, holder_ctie_width, holder_ctie_thick]);
     }
-  }
 }
 
 module RegistrationGroove(l){
@@ -162,10 +160,10 @@ module RegistrationGroove(l){
 module OneJig(){
   difference(){
     translate([-(jig_interval/2 + jig_overlap),
-              -(strap_width/2 + edgewall_width) - attach_offset,
+              jig_min_y,
               -strap_thick])
       cube([jig_interval + 2,
-           strap_width + edgewall_width*2 + attach_offset,
+           jig_max_y - jig_min_y,
            jig_main_zsz + strap_thick]);
     minkowski(){
       cube([main_slop*2, main_slop*2, 50], center=true);