The first design to be released is the Concentric, an 83 mm conical burr hand grinder.
As the name suggests, the design objective was to keep everything concentric. Everything important is mounted coaxially: the torque tube connects to the outer burr holder, and the drive shaft runs through the centre of the torque tube. That keeps everything aligned under load and through temperature changes.
Adjustment
Adjustment is by a knob mounted on the drive shaft. It is stepless and reads to 0.001 mm, and the dial rotates with the shaft so there is no float in the adjustment while the grinder is turning.
Flywheel
The 820 g stainless steel flywheel is only 60 mm in diameter, but because it is geared at 6.5 times crank speed it carries the kinetic energy of a much larger wheel — while keeping the machine good-looking in a kitchen. It also helps keep the weight under 8.5 kg, so the grinder is easy to move and efficient to ship.
Burrs and handling
83 mm burrs are the right balance of speed and usability: around 15 seconds to grind 20 g of beans to espresso size at a sensible pace.
The handle shapes and positions turned out to matter enormously. Designing the machine was straightforward; creating the style took imagination; making it work well with a human took a lot of trial and error.
Build quality
The build quality is well beyond what is normal in this industry. Every morning you use this grinder, I want you to feel it.
Plastic-free (almost). On its journey through the machine your coffee never touches plastic. The only plastic in the grinder is in the ball-bearing seals and the handle bush — for the health of you and the longevity of the machine.
