Instead of springs Patrick used some elastic bands, he suggests ¼ inch dental bands, to power the guns striker, trigger, and sear. There is no denying that the PM522 Washbear is quite a cleverly designed firearm that uses some unique solutions to operate the revolving barrel. When the gun is assembled, Patrick used epoxy to hold everything together and to hold the stainless steel tubing in place so his gun meets legal requirements. However unless chamber inserts are used, the cylinder assembly needs to be printed with nylon, as taulman 3D’s Bridge Filament was the only material that has been completely successful.

Patrick makes it very clear that his revolver should not be printed using standard PLA material instead he suggests all of the parts of the body be printed in ABS with 100% infill and maximum shells. Here is a brief video of the PM522 Washbear being successfully test fired: Patrick also suggests that subsonic ammunition is the best choice of ammo because it won’t break the sound barrier when it fires, resulting in no shock wave as the slug leaves the chamber. If what Patrick says about the PM522 Washbear is accurate, this is a significant upgrade from the Liberator, although he does warn that the gun isn’t intended for repeated usage. In contrast, the 3D printed Liberator handgun designed by Cody Wilson holds and fires only a single bullet, and doesn’t always survive for a second shot. By putting them together the frame is strong enough to contain the the pressure of firing and keep the cylinder layers from splitting. For instance, the gun frame is printed flat on its side while the revolver is printed standing up.

All of the stl files have been optimally orientated by Patrick in order to maximize the strength of the material and prevent failure.

Both barrels will fit in the same gun frame, so they are interchangeable. The frame of the PM522 Washbear was designed to hold either a six or eight shot pepperbox revolver, however the six shot is printed in a more durable nylon material while the eight shot is printed in ABS with steel chamber liners for extra strength. The optional 8 barrel revolver needs metal tubing inserts for each individual chamber.

3d printed liberator gun stl files