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Making espresso at home presents a familiar challenge for many activities. It could be better, cheaper, or easier to understand, but there are at most two choices. I can spend endless amounts of time and money tweaking and upgrading my equipment, chasing the best cafe flavor shots and always thinking of what else I can change.
Or you can build a highly configurable machine from open source hardware plans and Espresso Gaggia’s hot gut, as Norm Sohl did. Below is what Sohl did and other responses from retired programmers and technical his writers. His projects are now widespread in both Open Hardware and Espressohead his circles.
Like many home espresso aficionados, Sohl added a proportional-integral-derivative (PID) controller to his machine of choice, the Gaggia Classic Pro, for better control over temperature, pressure, and shots. I was aware that it could be changed in a number of ways, including making other changes to the . volume. It was Gaggiuino that Sohl was most intrigued by. This is a project that adds these with the help of an Arduino Nano or STM32 Blackpill, lots of electrical work, and open software.
It looked fine to Sohl, but as he told Ars in an email, he was pretty happy with the espresso dialed in on his Classic Pro. “[S]o Decided to build a new machine for experimentation. I didn’t want to risk not drinking coffee while experimenting with the new machine.” Luckily, he had an old machine, an Espresso Gaggia, so I wondered what Gaggia’s home espresso machine design was. It’s been pretty consistent for a decade. After descaling the boiler, he put the pump, the boiler, and, as he writes, “an experimental platform to try out the craziest things I’ve seen on YouTube and online.” “is.
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Sohl ended up creating a rough guide to creating your own highly configurable machine using common espresso machine parts and Gaggiuino software. From his machine, he recovered a pump with a pressure sensor, a boiler with a temperature sensor, an overpressure valve and an extraction head. Sohl used extruded rails and stiffeners to build the chassis of the new machine.
The high voltage board and components were assembled in a breadboard style onto an acrylic panel and held in place with poster tack adhesive. The 120 volt power connector was salvaged from the PC’s power supply and attached with a 3D printed bracket. Low voltage wires and components were also tacked to acrylic, individually crimped and heat shrink wrapped. The control panel was also 3D printed, allowing for toggle switches and a touch screen.
Sohl’s unit needs a lot more work. The exposed boiler and 120 volt wiring need to be hidden, and a drip tray is handy. But it works. The first shot was fast and poorly extracted. This suggests a finer grind and setting changes. Again, that describes pretty much every first-time home espresso setup, and Sohl hopes future versions of his project will utilize his Gaggiuino project’s unique circuit board design. He wrote that he plans to post his 3D project his files for sharing.
In an email interview, Sohl wrote that he received a friendly and encouraging response to his project.
Most people plan their way and wonder how deep they want to go into the weeds with the extra control. My advice (if they ask!) is to get a passable machine and grinder ( Get a Gaggia Classic and perhaps a Baratza Encore ESP grinder) and spend enough time learning how to use them. For example, my grinder is old and it took me forever to figure out how well I really need to do to get the kind of espresso I want.
When asked if he was intimidated by having more control over each shot, Saul replied, “Yes, but is that a good thing?”
The level of control is amazing and I’m just starting to dial in shots that are as good as I get from my stock machine every morning. The machine itself still needs work before going into daily use. We’d like to add a decent drip tray before it’s really practical. I would also like to try a digital scale. I honestly think it might be overkill for my espresso needs, but I really enjoy the detailed work in learning to build and use something like this. The satisfaction you get is probably as important as the final product.
We asked Sohl which is the hardest: hardware, software/firmware, or dialing in Espresso. The software flash worked without any programming on his part. Hardware required new skills, such as crimping connectors, but he went slow and learned from his small mistakes. Getting the espresso dialed in is probably the hardest, writes Sole.
Overall, “This is one of the most satisfying builds I’ve done. The combination of mechanical work, electronics, water and steam is challenging,” Sohl wrote. You can see more shots of the DIY machine and its details in his Sohl’s Substack, first seen on the Hackaday blog.
