I was just playing around with printable trapezoidal threads and before I realized it, I had designed a large machine vise… The vise has a clamping range of 120x120mm. It is good for circuit boards because plastic is non-conductive. Standard trapezoidal threads (30° thread angle ) or ACME threads (29° thread angle) are very difficult to print in an upright position. The overhangs are not supported by the thread geometry. Therefore my thread has a thread angle of 42°. This can be printed upright at 0.12 layer height without using supports. Print all threaded parts in an upright position with a layer height of 0.12mm or smaller. All other parts can be printed with 0.2mm or bigger layers. Support is needed for the Slider and the Jaws. For the Base support is optional but recommended. The other parts do not need supports. I am using 4 walls, 5 tops, 4 bottoms and 10% gyroid infill. See my 3mf file for more details and change it to your needs. The 3mf file is for Bambu Lab P1/X1 printer but shows the orientation of the parts. Just to mention it - this is a large vice. It needs more than 0.5kg filament. The gap between the parts is 0.25mm for all movable elements. The pins have a smaller clearance (0.15mm) as those are a press-fit. If necessary they can be hammered in position. I was using some very cheap filaments that had large tolerances in diameter. In that case you might need to rework the holes for the pins with a drill (Ø4mm) and sand the sliding surfaces evenly. This should not be necessary if you use quality filament. For the sliding surfaces and the thread I am applying candle wax as surface treatment (just rub it on). Then you have a nice and smooth vice action.