This is a new version of the parameterized Servo wheel for mobile robots:

http://www.thingiverse.com/thing:9071

These are the wheels used by many printbots such as Miniskybot or Scout. The improvements of the Version 4.0 are:

• Adaptation to the 3 types of Futaba 3003 servo horns: rounded, 4-arms and 6-arms
• New drills for attaching the horns. Now it is easier to screew the horns to the wheels

The sources are stored in the Miniskybot 2 github:

https://github.com/Obijuan/Miniskybot/

• Choose the kind of servo horn you want to use
• print the servo wheel for that horn
• Screw the servo horn to the wheel using the standard screws that come with the servo
• Put the O-ring around the wheel
• Attach the wheel to you robot!