This is for the Segway Skateboard over at Instructables.com (http://www.instructables.com/id/Easy-build-self-balancing-skateboardrobotsegway-/#step1). It is so that people can 3d print the wheel mounts instead of creating them out of metal brackets.Download the file, turn it into gcode, and print it out! There's a hole for the Axle of the Scooter Wheels, and imprints for screwing the mount to the board.