Two-Axis Coffee Machine is a Maker’s Take on the Perfect Pour-Over

Pour-over coffee is the way to go for many people; it’s a clean, flavorful cup that hits the spot in a way that automatic drip coffee can’t. The whole point is that slowly dripping water over fresh grounds brings out nuances and subtleties that an automatic coffee machine will rinse right down the drain. However, standing there waiting for the water to flow with a gooseneck kettle is about the most tedious thing you can imagine.

Then along comes a cool new handmade brewer created by a maker called zeroshot, which makes the entire process a breeze and requires no human intervention. Its frame is held together with simple aluminum extrusions linked together by T-nuts to provide stability without the extra weight that comes with a cumbersome design. The horizontal axis is on a cantilever arm and is driven by a belt to keep the entire motor low and steady. The vertical axis employs a belt and pinion arrangement, allowing the carriage to dangle over the brewing area and precisely place the tools directly over the waiting filter cup.

To get this contraption started, simply flip a handle, which powers a little grinder installed directly on the carriage and begins churning through your coffee beans as soon as the motor turns on. The grounds fall directly into the filter below, and because the carriage moves to keep them in line, there is no need for a separate hopper. Next comes the boiling water, which is simply sitting in a conventional electric kettle as you press a servo motor button to turn it on. When the water reaches the proper temperature, a peristaltic pump kicks in, pushing it through food-safe tubing and into a nozzle on the carriage, all without the chance of contamination.

This entire thing is about movement, with two stepper motors controlling the two axes, which are activated by some custom programming on an Arduino board to move it in a straight line, diagonally, or even in a curve. When moving in a straight line, the system matches speeds between the two axes to ensure that everything tracks correctly, whereas when drawing a circle, it offsets the motors to create sinusoidal motion, sampling points along the way to maintain things nice and smooth.

Finally, it all comes together with a spiral pour, in which the nozzle begins at the edge of the filter and works its way inwards in ever decreasing circles, spreading the hot water evenly and getting the grounds nice and saturated without any of the channels that form when water rushes through unevenly at first. Early versions had a bit of a wobble and a few splashes, but that was fixed with some 3D-printed tube guides and some positional adjustments.

As a result, the coffee is of high quality, comparable to hand-brewed. All of the flavors are there, the grounds have enough time to blossom, and the extraction is always perfect. It only takes a few minutes to start another one by simply repeating the sequence. So you simply sit back, listen to the smooth whir of the motors and the soft hum of the pump, and watch as the carriage glides along in its graceful dance.
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