1  use <voronoi/vrn2_space.scad>
 2  use <bend_extrude.scad>
 3  use <arc.scad>
 4  
 5  size = [300, 120];
 6  grid_w = 30;
 7  thickness = 2;
 8  spacing = 3;
 9  seed = 5;
10  $fn = 24;
11  
12  color("black")
13  bend_extrude(size, thickness = thickness, angle = 360) 
14      vrn2_space(size, grid_w, seed, spacing);
15  
16  r = size[0] / (2 * PI);
17  linear_extrude(size[1])
18      arc(radius = r - thickness, angle = [0, 360], width = thickness / 2);
19  
20  linear_extrude(thickness)    
21      circle(r);