Prusa Research
Bed Slinger (Smooth Rods + Nextruder)
Prusa MK4 & MK3.9 Maintenance Guide: Smooth Rods, Nextruder & Belt Tuning
The Prusa MK4 is a workhorse 3D Printing Glossary">FDM 3D printer featuring hardened smooth linear rods, linear ball bearings, the planetary Nextruder, and a loadcell auto-calibration system. Regular greasing keeps linear bearings running silently without rod scoring.
Key Maintenance Principles
- Smooth linear steel rods on X, Y, and Z require Prusa Lubricant / mineral grease every 60 days.
- Nextruder planetary gearbox should be cleaned of filament debris every 45 days.
- X and Y belt tension can be checked precisely using the Prusa Belt Tuner web audio app.
- Spring steel 3D Printing Glossary">PEI sheets require regular degreasing with dish soap and warm water.
1
Smooth Linear Rods & Bearings Greasing
Recommended Interval: Every 60 Days
Required Tools & Supplies:
Prusa Lubricant (or mineral grease)Lint-free cloth
Step-by-Step Instructions
- Wipe smooth steel rods on X, Y, and Z axes clean of old grease and accumulated dust.
- Apply a thin film of Prusa Lubricant grease along all rods.
- Move each axis slowly across its full stroke 3-4 times so the internal bearing balls pick up the lubricant.
Important Caution:
Never run ball bearings dry; dry bearings will score grooves into the hardened steel rods.
Frequently Asked Questions
What grease is best for Prusa MK4 smooth rods?
Use the official Prusa Lubricant or a high-quality mineral-oil-based grease with PTFE (such as Super Lube 21030).
Cite This Page
Use these formats to cite this page in research, reports, and documentation. Both snippets are copy-ready.
APA 7
APA
TryAR Labs. (2026, August 27). Prusa MK4 & MK3.9 Maintenance Guide: Smooth Rods, Nextruder & Belt Tuning. MakerWorld Estimator. https://estimator.tryar.in/maintenance/prusa-mk4BibTeX
BIBTEX
@misc{tryarlabs2026prusamk4,
title = {{Prusa MK4 & MK3.9 Maintenance Guide: Smooth Rods, Nextruder & Belt Tuning}},
author = {{TryAR Labs}},
year = {2026},
month = {aug},
url = {https://estimator.tryar.in/maintenance/prusa-mk4},
note = {MakerWorld Estimator}
}Calculate 3D Print Costs in Real-Time
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