Summary

Small prototype robot.
There are many versions out there this is one of them ;-)
Using servo's and a arduino nano.
And printed stuff

See it in action:
http://www.youtube.com/watch?v=5CfzsNUcKHk
Without head ;-)
http://www.youtube.com/watch?v=4UULxM7JtcY

This is work in progress but building a custom quadcopter and that takes most of my time but wanted to upload it anyway

Instructions

Get
Two Modelcraft Standaard RS 2 Servo's (Conrad) or something similar
One Tower Pro Mini Servo or something similar
One Battery Holder for 3 AA batteries
One Small Breadboard And mount a Arduino Nano
One ultrasonic sensor (ebay or dealextreme)

Modify de RS2 servo's so that they will turn continuously (google it ;-)

Print:
Base_level
Battery_level
BreadBoard_level
Battery_stop
Servo_holder

thing (nice wheels ;-) also nice protobot)
http://www.thingiverse.com/thing:18377
thing (nice caster)
http://www.thingiverse.com/thing:20471
thing (nice head)
http://www.thingiverse.com/thing:24858

Mount the modified servos to the base level use m3 bolts
mount coasterl with m3 bolts
Mount the battery level using 3 m3 bolts
Mount servo holder to the breadboard level use 3 m3 bolts
Mount the breadboard level using 3 m3 bolts
Glue on the broadboard.
Insert sensor into the sensor holder en glue it to the mini servo (see photo)
Mount the wheels on the RS2 Servos (adding a bit off hotgleu helps) i used jumping rope for the tires (used superglue to make than just cut of the right length)
Insert battery holder and and battery stop (there is a hole for the m3 bolt)

Wiring:
TODO please comment and i will add some instructions how to do this.

Upload very basic program to arduino (PieterBot.zip)
Tinker with it and make it beter ;-)

Things to do:
add extra ball caster
better battery stop
better servo holder
better software
add laser for no good reason ;-)

PieterBot (yes there are many out there :)