This is a Mecanum wheel http://en.wikipedia.org/wiki/Mecanum_wheel I saw that somebody else had a printable one, but it was not shared. So I made this.You will have to use glue, or acetone, or something to accach the pieces together. This is designed to use 3mm filament as axles for the wheels.I also uploaded the blender file, in case anyone wants to change stuff.Print all the bits out. Either individually or in the sets I made. Attach the wheel holders to the hub. Make sure to get them all lined up properly. Add the wheels using 3mm filament. Make a sweet robot. :)