diff --git a/examples/arc_tiled_lines.scad b/examples/arc_tiled_lines.scad
deleted file mode 100644
index 4a976098..00000000
--- a/examples/arc_tiled_lines.scad
+++ /dev/null
@@ -1,40 +0,0 @@
-use <util/rand.scad>;
-use <hull_polyline2d.scad>;
-use <arc.scad>;
-use <experimental/tf_ring.scad>;
-
-module arc_tiled_lines(size, angle, step, line_width = 1) {
-    sizexy = is_num(size) ? [size, size] : size;
-    s = is_undef(step) ? line_width * 2 : step;
- 
-    function rand_diagonal_line_pts(x, y, size) = 
-        rand(0, 1) >= 0.5 ? [[x, y], [x + size, y + size]] : [[x + size, y], [x, y + size]];
-        
-    lines = [
-        for(x = [0:s:sizexy[0] - s]) 
-            for(y = [0:s:sizexy[1] - s]) 
-                rand_diagonal_line_pts(x, y, s)
-    ];
-    
-    for(line = lines) {
-        pts = [for(p = line) tf_ring(size, p, size[0], angle)];
-        hull_polyline2d(pts, width = line_width);
-    }
-    
-    arc_width = line_width * 2;
-    arc(radius = size[0], angle = angle, width = arc_width, $fn = 36);
-    arc(radius = size[0] * 2, angle = angle, width = arc_width, $fn = 36);
-    
-    if(angle != 360) {
-        hull_polyline2d([[size[0], 0], [size[0] * 2, 0]], width = arc_width);
-        rotate(angle) 
-            hull_polyline2d([[size[0], 0], [size[0] * 2, 0]], width = arc_width);        
-    }
-}
-
-size = [20, 100];
-line_width = .5;
-step = 1; 
-angle = 360;
-
-arc_tiled_lines(size, angle, step, line_width);
diff --git a/examples/tiled_line_mobius.scad b/examples/tiled_line_mobius.scad
new file mode 100644
index 00000000..04b31952
--- /dev/null
+++ b/examples/tiled_line_mobius.scad
@@ -0,0 +1,40 @@
+use <util/rand.scad>;
+use <hull_polyline3d.scad>;
+use <experimental/tf_ring.scad>;
+
+module tiled_line_mobius(size, twist, step, line_width = 1) {
+    sizexy = is_num(size) ? [size, size] : size;
+    s = is_undef(step) ? line_width * 2 : step;
+ 
+    function rand_diagonal_line_pts(x, y, size) = 
+        rand(0, 1) >= 0.5 ? [[x, y], [x + size, y + size]] : [[x + size, y], [x, y + size]];
+        
+    lines = concat(
+        [
+            for(x = [0:s:sizexy[0] - s]) 
+                for(y = [0:s:sizexy[1] - s]) 
+                    rand_diagonal_line_pts(x, y, s)
+        ],
+        [
+            for(i = [0:step:size[1] - 1])
+                [[0, i], [0, i + step]]
+        ],
+        [
+            for(i = [0:step:size[1] - 1])
+                [[size[0], i], [size[0], i + step]]
+        ]
+    );
+    
+    for(line = lines) {
+        pts = [for(p = line) tf_ring(size, p, size[0], 360, twist)];
+        hull_polyline3d(pts, thickness = line_width);
+    }
+}
+
+size = [20, 100];
+line_width = .5;
+step = 1; 
+twist = 180;
+$fn = 4;
+
+tiled_line_mobius(size, twist, step, line_width);