R-38 Pneumatic Bourke Rotary Engine

thingiverse

The R-38 is the third rotary engine developed after the R-66 and R-52. Measuring 38 x 38 x 48 mm³, it's the smallest in this series so far. This tiny engine outperforms its larger counterparts, handling airflow through 4 mm pneumatic tubes with ease. The crankshaft of the R-38 is constructed entirely from metal, while the crank radius measures a mere 3 mm, resulting in a piston stroke of 6 mm. The piston's surface area is an impressive 16 x 12 mm², yielding a force of 38 N at 0.2 MPa (2 bar) pressure. When combined, this produces a theoretical torque of 110 Nmm at 0.2 MPa. Filament generously sponsored by Fillamentum. The entire engine is crafted from PLA, featuring three distinct colors: Everybody's Magenta for the rotor, Pearl Night Blue for the housing, and Gold Happens for the bearing cage.