Open Source Espresso Machine Is One Delicious Rabbit Hole Inside Another

In a Substack post, Norm Sohl describes how he built a highly configurable machine out of open source hardware plans and the thermal guts of an Espresso Gaggia. An anonymous reader shares a summary from Ars Technica: Like many home espresso enthusiasts, Sohl had seen that his preferred machine, the Gaggia Classic Pro, could be modified in several ways, including adding a proportional-integral-derivative (PID) controller and other modifications to better control temperature, pressure, and shot volumes. Most intriguing to Sohl was Gaggiuino, a project that adds those things with the help of an Arduino Nano or STM32 Blackpill, a good deal of electrical work, and open software.

Sohl ended up creating a loose guide to making your own highly configurable machine out of common espresso machine parts and the Gaggiuino software. From his own machine, he salvaged a pump with a pressure sensor, a boiler with a temperature sensor, an overpressure valve, and brew head. Sohl made a chassis for his new machine out of extrusion rails and stiffening plates. The high-voltage boards and components were assembled breadboard style onto acrylic panels, held up by poster-tack adhesive. A 120-volt power connector was salvaged from a PC power supply, then mounted with a 3D-printed bracket. The low-voltage wires and parts were also tacked onto acrylic, individually crimped, and heat shrink-wrapped. And the control panel was 3D-printed, allowing for toggle switches and a touch-panel screen.

There's more work to be done on Sohl's unit; the exposed boiler and 120-volt wiring need to be hidden, and a drip tray would be nice. But it works. The first shot was fast and under-extracted, suggesting a finer grind and settings changes. Then again, that describes almost every first-time home espresso setup. Sohl writes that he hopes future versions of his project will make use of the Gaggiuino project's own circuit board design and that he'll have his 3D project files posted for sharing.

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