3D Printed Assemblies
One of the advantages of additive manufacturing is the potential to create fully assembled machines. I was playing with this concept in OpenSCAD and made a Sarrus linkage that is printed almost fully assembled.
As a rule of thumb, typical FDM 3D printers can print overhangs without any support structures provided the angle of the overhang is 45 degrees or steeper. Taking advantage of this capability, the hinges are made from conical pins that mesh inside conical holes. The linkage is printed with the hinges in place and assembled, with the exception of the last hinge.
After printing, the last hinge is snapped into place.
The model was written in OpenSCAD and the linkage dimensions are customizable. It is available for download at Thingiverse.