If you have never "Whimmy-diddled," it is never too late to learn. You take the Diddle stick and stroke the notched Whimmy to cause the propellers to turn. Advanced Whimmy-Diddling is where you can stop the spinning and start again in the reverse direction. The double-barreled model, an advanced design from Tennessee, gives one the opportunity to cause both propellers to go in the same direction or in opposite directions simultaneously.