After my gearless follow focus, here a geared one. Swapping the lens is not as easy as it is with the gearless one and you need a lens-gear for every lens but you also need no pressure to create friction. The follow focus and lens gear are compatible with industry standard 0.8 pitch follow focus equipment. The axis use 608 bearings to reduce any noise of threaded rods on plastic that could be picked up by the microphone and to make this run as smooth as possible. The mounting is for an industry standard 15mm rail support system such as my 3d printed shoulder rig: thingiverse.com/thing:7278 With a follow focus you have precise, manual control over the focus (or zoom) of your lens. It is used for professional filming where precise control of the focus is required and where a pumping autofocus would simply ruin the take. Commercial versions are sadly terribly expensive. :( Photos: picasaweb.google.com/Marcus.Wolschon/201105_201106_geared_follow_focus?feat=directlin Blog post: marcuswolschon.blogspot.com/2011/06/3d-printed-geared-follow-focus.html Video (Part I) youtube.com/watch?v=imy2UaUzNeY Update: (2011-07-17) Added lens_gear_version3 with a wider tap for the bolt.