This Coffee Maker Turns Steam Into Action — Thanks to a Clever Heron's Engine
Ancient Greece's first steam engine is put to work here in miniature, pumping boiling water over coffee grounds for your morning cup.
Forget steaming the milk, pseudonymous maker "graycs06" has designed a pleasingly over-engineered coffee maker that turns steam into power for a pump — thanks to an invention created in ancient Greece known as the aeolipile or "Heron's Engine."
"The Heron Engine-powered coffee maker incorporates the principles of the Heron Engine, developed by Hero of Alexandria in ancient Greece, into a coffee maker to make a unique, yet gorgeous piece of coffee equipment," graycs06 explains of the unassuming tin-can-on-a-stand-wearing-a-hat. "Heron's engine is one of the earliest forms of the steam turbine and works by heating water in a chamber and pushing it through small tubes to generate a spinning motion."
"Spinning motions" aren't usually associated with making coffee, unless you count the grinder, but in this unusual coffee maker the motor — the "hat" sitting on top of an upcycled tin can — has a real purpose to serve: driving a pump that feeds boiling water from the bottom of the can to a pour-over coffee pot to serve up a morning's Joe.
The idea is simple: when there's a sufficient source of heat placed underneath the can, the water inside heats up. As it reaches boiling point, it causes steam to shoot out of bent copper pipes at the top of the "hat" — causing it to spin from the thrust thus generated, turning a pump that then feeds the boiling water from the tin can over the coffee grounds in the filter and finally into the pot.
"The spinning engine on top turns a shaft connected to an impeller inside the machine that forces water back out through the larger diameter copper tubing into the coffee grounds," graycs06 explains. "This method ensures that water only reaches the coffee grounds once water has reached the boiling point."
The non-upcycled parts of the project were designed in Autodesk Fusion 360 and machined using a CNC waterjet cutter, while the Heron's engine and impeller casings and the shaft connecting the two were created using a lathe. A ball-bearing ensures the engine can turn freely — though in the current proof-of-concept prototype is secured using JB Weld, which graycs06 admits is not food safe. "If you use [JB Weld]," the maker notes, "you should not consume the things it touches."
The project is documented in full on Instructables.