Investigating the operation and construction of the Gee-Haw Whammy-Diddle

Tri Tran and Dan McGinnis

The Gee-Haw Whammy-Diddle is a rural, usually handmade toy. Comprised of a wooden dowel carved with regularly spaced grooves along its length, a small propeller affixed to the end is made to rotate by rubbing a rod along the grooves. The rotational direction of the propeller can be controlled via the use of the location of the thumb of the hand holding the dowel.  In this paper, we will investigate the hypotheses previously made explaining the physical mechanisms by which this toy operates. In addition, we will determine the effect that several different construction methods (e.g. material and shape of propeller and dowel, spacing of grooves), have on the viability and observable properties of motion.