Nutcracker

Of all of the nutcrackers that I have encountered the best have been the wooden ones that consist of a 'cup' body with a wooden threaded 'bolt' plunger that screwed into the side of the cup to crush the nut between the end of the plunger and the inside of the cup. The advantage this design has over lever based nut crackers is that once the nut's shell fails it is very easy for a lever based nut cracker to go on and crush the rest of the nut, while the screw plunger versions do not.

This nutcracker was designed for FDM printing in PLA without any support.

A detail that I wanted in this design is that the load bearing face of the screw thread should be as perpendicular to the load as practical. A more traditional steeply sloped face on this side of the thread would increase the friction under load and that would be undesirable in a nutcracker.

Testing various 'cup' designs eliminated the possibility of printing with the threaded hole orientated vertically; the end always cracke