so this is that stepper gear i showd on tube http://www.youtube.com/watch?v=JcfUoUdpeoA argument has bean made that it doesn't work under load. and its probably true but since its popular on ytube upload it anyway.probably need to redraft it to be printable. Scale is of and its pie sliced not monolithic. anyway it would be far easier to cut it with a end mill.anyway by demand here it is