The file 'Shop-Vac Vacuum Relief Valve 3D Printer Model' is (stl) file type, size is 146.3KB.
This is a vacuum relief valve that can be screwed in place of the drain at the bottom of a shop-vac. This does not require any modification to the vacuum, and you can quickly reverse it just by screwing the original cap back in place. This probably works best with a bag, although I carefully designed it to not extend into the body of the vacuum, so it may work ok without one.
This requires a 6mm bolt and nut and a spring of some sort.
shopvac_release_valve.stl | 342.4KB | |
shopvac_release_valve_cap.stl | 70.5KB |