Automated filter wheel changer

This Arduino-controlled open-source automated filter-wheel changer is set up to move to 8 different filter positions. Normally these devices are used in scientific experiments that need precision optics. Commercial versions cost over $2,500 and you can make this yourself for less than $50. So if you make just one -- you more than justify the purchase of your own open source 3-D printer!
More info: http://www.appropedia.org/Parametric_automated_filter_wheel_changer