Mini Clamp

thingiverse

Small clamp with a unique planetary gearbox mechanism for demonstration or recreation. Prints in place fully assembled without supports. IMPORTANT: Print at 0.2mm layer height if using the default model, otherwise ensure layer_h parameter matches your layer height if customizing. Check preview before printing and ensure the 1-layer gap is preserved in the outer ring gears. Use a sharpened spatula, razor or hobby knife to de-laminate the 1-layer gaps (watch fingers and listen for the "crack"), then turn the knob just a little to get the gears moving. Now "crack" the jaws apart manually by back-driving by a few mm (there should be a little backlash). Now all the parts are free, it will be a bit stiff at first but opening and closing a few times will loosen it up. Then apply petroleum jelly or lubricant of choice to gears and work it in (again by opening and closing a few times). The main improvement of this iteration (aside from a few bug fixes - man, I wish I put this gearbox in github from the beginning) is an internal ridge which acts as a bearing surface. The previous design was very sensitive to gear clearances due to the gears themselves acting as bearings. Too much play in the gears resulted in the jaws going off center and binding. This should allow for more tolerance in the gears and alleviate some of the shear force on the planet gears. I have also incorporated the gear formulas so we don't need the spreadsheets anymore (unless you're hunting for a particular gear ratio).