Thread cutting on an Emco Unimat micro-lathe
I acquired a tiny Emco Unimat SL manual lathe and wanted to be able to cut threads on it, but it does not have a power feed or change gears to drive the carriage from the spindle, so I used FreeCAD to design a 3D-printed attachment that allows various pitches to be cut.
It's more work than a tap and die, but can cut weird sizes (like the M12x1.0 used for the spindle) and was also a good exercise in learning to use parametric CAD.