Adjust motor assembly tension
A loose backplate may cause some rattling or unpleasant noise. Tightening it is a quick adjustment.
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Regrease motor input shaft
An ungreased motor shaft may cause some minor vibration or rattling. We recommend Molykote 111 or SuperLube.
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Tighten the gearbox
A slightly loose gearbox is the most common cause of vibration or noise while grinding, and tightening it is a quick adjustment.
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Pitch that rises and falls
If the motor sound changes up and down while grinding, check whether the Z1 shares an outlet or circuit with a kettle or espresso machine. When those appliances heat, the voltage dips and the motor slows. Plug into a different outlet, or grind between heating cycles. This will not impact your grinder's performance.
Motor sound varies a little
Small differences in motor tone between grinders, and even between outlets in the same home, are normal. Household power affects how a motor sounds.
Still vibrating?
If these steps do not work, please contact support at info@zerno.co with a short video with sound.
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