This is a 3D printable miniature of special container with RKR rotary piston blower units - part of a small-scale model of methane-filtering station for closed type coal-mines. This contains 4 small engines - that convert purified gas to electricity - giving it back to the coal mine.

Print it layed on it's back - supports needed. 50% infill, 2 walls, 0,2 mm in height.