This is a very simple follow-focus using a roller-blade or skateboard -wheel instead of gears. It's great to experiment with a follow focus on a shoulder-rig without investing a lot of time and effort into a more complex geared or even remote follow focus. See thingiverse.com/thing:7256 for a much cooler but also more complex design requiring electronics and microcontroller-programming. Update: I added a (not yet tested) straight version of this follow focus because with my new matte box there was not enough space to mount this anymore. Video: youtube.com/watch?v=FHwVil_Lvcg&feature=player_embedded blog post: marcuswolschon.blogspot.com/2011/04/printing-gearless-follow-focus.html photo album: picasaweb.google.com/Marcus.Wolschon/20110325Bis201105ShulterRigBauen?feat=directlink forum post: forums.reprap.org/read.php?88,75536 project in my personal wiki: sourceforge.net/userapps/mediawiki/marcuswolschon/index.php?title=Projects/Camera/ShoulderRig#status IF YOU HAVE NO ACCESS TO A 3D-PRINTER AND CAN't FINE SOMEONE ELSE TO PRINT THESE FOR YOU, YOU CAN HAVE SHAPEWAYS PRINT THESE FOR YOU: shapeways.com/shops/marcuswolschon?section=Camera+and+Filming