Drag to turn; right-drag, shift-drag or move two fingers to slide the view; scroll or pinch to zoom in on whatever is under the pointer; double-click a part to turn round it, and Reset view to go back. Draw Explode to take it apart. Every part is the cut files’ own outline at 3mm: three happy paddles glued into the comedy slat underneath, three sad ones into the tragedy slat above, drawn a few degrees open, and a four-strip handle block, darker, on each slat’s outer face over its engraved rectangle. The red cord is the rope hinge laced through the three holes at the far end; its length and lacing are yours, and this is one way.