Gelbart Linear Stage

thingiverse

Dan Gelbart is a talented engineer, designer, and entrepreneur. In the included screenshot you can see a photo of his linear-positioning stage, which I've attempted to recreate with some minor modifications. This design is intended as a demo object and would require further development to take into account material selection. I don't recommend 3D printing this in plastic due to its thin .010" walls, but those walls may be thinner than necessary, making it potentially possible to print in plastic after all. Ideally, this design should be cut from a single block of metal using a CNC waterjet cutter. The major modification I've made is expanding the size of the stage mounting holes for 1" square optical mounts, creating a 3x3 mounting pattern and four additional in-pattern mounting holes. Gelbart's device features a 1:15 lever ratio, whereas this design has a 1:24 ratio. This is an untested, unvalidated copy intended for demo purposes only, so its performance is unknown. Included is a model and print for a precision screw from McMaster-Carr designed to be used with the device to actuate it. The brass sleeve will fit in the bottom hole near the lever, providing the necessary force. A spring could be added behind this same bottom lever to provide opposite force, and there's enough clearance to insert the brass sleeve on the inside of the bottom hole. At the top of the device is another 1/4" hole for a precision measuring device to measure stage movement. Ideally, this design should produce a stage that can actuate in millionths of an inch with no backlash or hysteresis. The screenshot was taken from Gelbart's amazing 2012 videos on prototyping called "Making Prototypes," which can be found at https://www.youtube.com/watch?v=xMP_AfiNlX4.