Air Paddling Duck - single arm & triple arm versions

prusaprinters

Print two of the paddle, one of the body, one of this custom 1.5” PVC end cap and one of the backside washer. Procure one 5mm diameter x 100mm long precision dowel pin (McMaster P/N 93600A299), one M4 precision shoulder bolt having M5x25 shoulder (McMaster P/N 90278A375), one M4 nut and one M4 lock washer.Except for the fit up of the dowel pin to the end cap, which should be an interference fit, all the other fits must be clearance. At the default extrusion multiplier of 1.0 both of my printers print holes generally about 0,1mm small on diameter. Instead of constantly adjusting the multiplier I often, when fit-up is critical, allow the holes to print small and then drill to suit with my full machinist bit set. The final assembly here should rotate freely on the pin. The paddles must instantly spin when you blow lightly on them. Both flat and contoured paddle designs are included for the single arm version.Observed angle of paddles relative to a plumb line indicates strength of wind. Testing will reveal how much wind speed is required to have the paddles go over center and become a whirligig. As I reside in Florida it might take a hurricane or at least a tropical storm - we'll see. I may model an opposite hand version of the contoured paddle so that the paddles will turn in the same direction. My original triple arm version would not spin for obvious reasons. Currently working on a super-ceding airplane whirligig with conventional propeller.