Liquid fuelled engines are throttleable and monstrously powerful, but highly complex. Solid rocket engines are simple and cheap, but once you light them, they’re going full-bore until burnout. Hybrid rocket engines offer perks from both worlds, with simple solid fuel and the ability to throttle down by regulating oxidizer flow. Naturally, [Integza] decided he should try and 3D print one. The build came about somewhat by accident, as the 3D printed casing of one of liquid-fuelled rockets continued burning once the fuel was turned off. This prompted the realization that he could 3D print rocket fuel, and simply supply oxygen, creating a hybrid rocket. Most of the rockets self-destructed within a few seconds and thrust was minimal, but the basic concept should be a goer.

Read the full article at Hackaday