stdin.scad

--- skateboard-box.scad	2014-06-05 18:58:02.873415019 -0700
+++ -	2014-06-05 18:58:08.203617555 -0700
@@ -55,11 +55,15 @@
 
 module box (x, y, z, wallwidth)
 {
-    difference() {
-        cube([x, y, z], center=true);
-        translate([0, 0, wallwidth])
-            cube([x-2*wallwidth, y-2*wallwidth, z], center=true);
-    }
+	union() {
+		difference() {
+			cube([x, y, z], center=true);
+			cube([x-wallwidth, y-wallwidth, z], center=true);
+		};
+		translate([0, 0, z * -0.5]) {
+			cube([x, y, wallwidth], center=true);
+		};
+	}
 }
 
 module battery () {