A wobbling crank, burrs that touch, a cone that sits slightly off-centre, fines in your grounds. Every one of these gets reported to us as a fault, and every one of them is either a deliberate design decision or simply what coffee does. Here's what's going on, and the short list of things that genuinely do warrant a message.
1. The crank wobbles on the axle
Deliberate, and important. The connection between crank and axle is intentionally loose, because a tight one would make removing and refitting the crank and lid a fiddly, two-handed job every single time.
We tested this carefully during the design process to find the right amount of play. It has no effect on the axle, the burr mechanism or the grind — only on how pleasant the grinder is to use.
2. The burrs touch at fine settings
Normal, and not damaging. The cone is built as a floating cone — it has a small amount of flexibility on the axle rather than being rigidly fixed, which is a design choice with real performance benefits.
At fine settings the burrs may make some contact. They won't damage each other; the materials and the geometry are designed for it. If the contact seems heavier than you'd expect, it's usually worth a clean — a build-up of coffee dust changes how everything sits.
3. The burr cone looks off-center
Same cause, same answer. With the grinder empty and no load on the burrs, you can move the cone on the axle, and the spring may leave it sitting very slightly off-centre. It looks alarming the first time you notice it.
The moment you start grinding, the cone follows the centricity of the axle and the burr ring. The outer ring is aligned and
calibrated against the axle by hand at the factory, using the three mounting screws on the base — which, while we're here, you should never adjust or remove.
4. There are fines and boulders in the grounds
Unavoidable, in every grinder ever built, and here's why.
Roasted coffee is brittle and organic in structure. It doesn't fracture cleanly along neat lines — it shatters, producing both extremely fine dust and, at medium and coarser settings, irregular larger fragments. Both appear in any ground coffee you have ever brewed.
The meaningful question isn't whether they exist, but whether a burr set keeps them at levels that help the extraction rather than hurt it. We develop and test burr geometry in our laboratory specifically by analysing particle distribution, which is where the shape of NITRO BLADE® comes from.
So: don't be alarmed by what you can see in the tray. Check the grinder is clean and correctly assembled, then find the setting that tastes best to you.
5. There's no red O-ring in mine
There shouldn't be. Older grinders included a small red O-ring between the washer and the spring, whose only job was to hold the lower washer in place during disassembly. It was never a functional part of the mechanism.
It's no longer fitted to current production models — we found the grinders simply worked better without it. If yours arrived without one, nothing is missing and nothing has been left out.
6. It's much harder to turn at espresso settings
Physics rather than fault. Finer grinding means more fracturing per revolution, which means more force. Every hand grinder does this.
What you can change is grip and leverage — there's a full guide in why your Comandante gets harder to turn at fine settings, starting with the wristband trick that costs nothing.
7. The wooden knob squeaks
Natural wood running dry against the crank. A trace of food-safe oil fixes it in about two minutes — see the squeaking knob fix.
So what is worth telling us about?
We'd genuinely rather hear from you than have you living with something that isn't right. Get in touch if:
- The resistance is notchy or gritty rather than smooth — particularly if it catches at the same point in every rotation.
- Something rattles that didn't used to.
- The grinder won't hold a setting, drifting coarser as you grind.
- A part is visibly damaged, or has gone missing.
- You've dropped it and it hasn't been the same since.
Most of these are solved with an inexpensive part from spare parts — a spring, a set of ball bearings, a central axle. And where they aren't, there's a repair service. We build these grinders to be fixed, not replaced.
The short version
A wobbling crank, touching burrs, a floating cone and visible fines are all normal. Notchy resistance, rattles and a setting that drifts are not. When in doubt, clean it first — then ask us.
