sewing-table: interlock

diff --git a/sewing-table.scad.m4 b/sewing-table.scad.m4
index e8f6b7a7c68a4e79ee2c6310a0a7200708d48609..eb7dc2a710aefa6aedc1e534f7cbc3ad0047c697 100644 (file)
--- a/sewing-table.scad.m4
+++ b/sewing-table.scad.m4
@@ -103,10 +103,20 @@ module RoundLeftCorner(this_post, right_post) {
 }
 
 module InterlockCore(r) {
+  dx = sqrt(3) * r;
+  $fn= 80;
   translate([0, -thehd[0], 1]){
     mirror([0,0,1]){
       linear_extrude(height=tile_th+2){
-       circle(r=r, $fn=40);
+       circle(r=r);
+       difference(){
+         translate([-dx, -0.1])
+           square([ dx*2, r/2 + 0.1 ]);
+         for (xi = [-1, 1]) {
+           translate([ xi*dx, r ])
+             circle(r=r);
+         }
+       }
       }
     }
   }