Bed Leveling & Load Cell Calibration

The MK4 has no separate PINDA probe. Instead, a loadcell built into the Nextruder senses tiny amounts of force when the nozzle itself touches the bed, which the firmware uses for both the single first-layer reference point and a full mesh across the bed.

Advantages over PINDA

• No probe-to-nozzle offset to keep accurate — the nozzle is the probe.
• No temperature-based probe drift to compensate for, since it's a physical touch rather than an inductive reading.

"Calibration failed" / inconsistent touch detection

1. Clean the nozzle tip — the most common cause; any residue changes exactly when the loadcell registers contact.
2. Confirm the sheet is fully seated on its locating pins, not shifted or lifted at a corner.
3. Avoid probing on a contaminated bed — dust or a stray piece of filament under a touch point throws off that reading, same underlying issue as debris under a MK3S+'s PINDA point.

First layer good in the center, off at the edges

Re-run the full mesh calibration rather than just the single-point one — this is the loadcell equivalent of MK3S+ Mesh Bed Leveling correcting for sheet warp across the whole bed.

Tip: If you swap print sheets often (smooth vs. textured), keep in mind that a different sheet's exact surface height can shift slightly — re-run first-layer calibration after switching sheet types, not just after switching printers or nozzles.