Grabbers

• http://www.eurobricks.com/forum/index.php?showtopic=80021
• http://www.eurobricks.com/forum/index.php?showtopic=80645
• http://nxtgeek.blogspot.com.au/2012/06/mobile-skid-steer-arm.html

Spinner

• http://www.nxtprograms.com/top_spinner/steps.html