This is the parameterized version of the servo wheel. The wheel diameter, height and o-rings parameters can be defined by the user. These are the type of wheels we are using for our printable robot projects. For example, the Miniskybot robot ( http://www.thingiverse.com/thing:7989 )Currently the target servo is Futaba 3003.1.- Set the parameteres 2.- Create the stl file 3.- Print the wheels 4.- Attach the servo horn 5.- insert the O-ring 6.- Ready to use for building robot!