Prusa MK4 & MK3S+ Maintenance Guide
Prusa publishes one of the most detailed official maintenance schedules in the hobby — this is the shortlist of what actually matters most.
Maintenance schedule
| Task | Interval |
|---|---|
| Lubricate smooth rods (X/Y/Z) | Every ~3 months or 500 hours of printing |
| Check belt tension | Every ~3 months |
| Check extruder idler tension | Every ~1–2 months |
| Clean/replace nozzle | Every 6–12 months, sooner with abrasive filament |
| Re-run first-layer / Live Z calibration | After any nozzle swap or noticeable first-layer change |
| Check probe (PINDA/SuperPINDA on MK3S+) for drift | If first layer height varies with ambient temperature |
Why lubrication is the single most-cited maintenance item
Dry or under-lubricated smooth rods on the X/Y/Z axes increase friction, which shows up as inconsistent layer lines, ringing, or unusual stepper motor noise long before it causes an outright failure — Prusa's own manual calls out a schedule specifically because this is the maintenance item most likely to get skipped since the printer still runs fine for a long while as it degrades. A light, printer-specific grease applied per the official manual matters more here than on printers with sealed linear rails.
MK4's automatic calibration vs. MK3S+'s more manual process
The MK4 added an accelerometer for input shaper (resonance) calibration and generally automates more of the tuning process than the MK3S+, which relies more on manual Live Z adjustment and the PINDA/SuperPINDA probe for first-layer height. If you're used to one and moving to the other, expect the calibration workflow itself to be meaningfully different, not just the printer's speed.
Probe drift is a well-known, well-documented quirk
The PINDA and SuperPINDA inductive probes used on MK3S+ can shift their trigger point slightly with ambient temperature, which shows up as a first layer that's fine in the morning and slightly off by afternoon in a room with real temperature swings — this is a widely known characteristic of the sensor type, not a defect, and Prusa's firmware includes temperature compensation for exactly this reason. If first-layer height seems to drift with room temperature rather than anything you changed, this is the likely explanation.