Spiro Gear Drawing Apparatus

thingiverse

This project led to my Gear O' Clock gear profile featuring a simple continuous 0.075 radius. Create your own using the formula provided in the video link (http://www.youtube.com/watch?v=VHtRhu262zk). Print out the gears, use a mechanical pencil, Sharpie Pen or similar fine drawing tool, and draw various shapes by holding an outer gear and placing the utensil into one of the inner gears. Feel free to modify my design for new gear creations; share your working designs as derivatives. Gear teeth diameter is 0.15 inches (see drawing). To calculate circumference, multiply number of teeth by 1.5 and divide by pi to get the diameter needed for your gear teeth's pitch circle or center of diameter. Don't forget to post more designs as derivatives! Note that the units are in inches so no complaints about sizing.