First-Time Setup & Calibration

Before powering on

1. Remove all shipping foam and the zip-ties securing the gantry and print sheet clamps.
2. If you built the MK4 from a kit, follow Prusa's official assembly manual step by step rather than skipping ahead — the self-test firmware checks depend on cables being seated in the right order.
3. Insert the print sheet fully onto the heatbed's locating pins before your first print.

Running the calibration wizard

The MK4 replaces the MK3S+'s separate XYZ/PINDA calibration steps with a single guided Calibration Wizard, triggered automatically on first boot or from the menu:

1. Selftest — checks fans, endstops, thermistors, and the loadcell before anything else runs.
2. XYZ calibration — squares the axes, same purpose as on the MK3S+ but automated.
3. First-layer calibration — instead of a PINDA probe, the Nextruder's built-in loadcell senses the nozzle touching the bed directly, both for the single reference point and for a full-bed mesh. Follow the on-screen prompts to confirm the detected touch is correct.

Tip: Because the loadcell probes with the actual nozzle rather than a separate sensor, keep the nozzle clean before calibrating — a blob of stuck filament on the tip throws off the touch detection.

Input shaping

Run the Input Shaping calibration after XYZ calibration — it measures the frame's resonance per axis and lets the firmware compensate for it, which is a large part of how the MK4 prints faster than the MK3S+ without more ringing. Re-run it if you relocate the printer.

First print

Use the bundled first-print test model before moving to your own files — it's a good check that the Nextruder, calibration, and loadcell are all agreeing with each other.