Added polyholes.scad from Nophead

polyholes.scad

@@ -0,0 +1,25 @@
+// Copyright 2011 Nophead (of RepRap fame)
+
+// Using this holes should come out approximately right when printed
+module polyhole(h, d) {
+    n = max(round(2 * d),3);
+    rotate([0,0,180])
+        cylinder(h = h, r = (d / 2) / cos (180 / n), $fn = n);
+}
+
+module test_polyhole(){
+difference() {
+	cube(size = [100,27,3]);
+    union() {
+    	for(i = [1:10]) {
+            translate([(i * i + i)/2 + 3 * i , 8,-1])
+                polyhole(h = 5, d = i);
+                
+            assign(d = i + 0.5)
+                translate([(d * d + d)/2 + 3 * d, 19,-1])
+                    polyhole(h = 5, d = d);
+    	}
+    }
+}
+}
+