The Complete Guide to Prusa MK4 Maintenance

Most 3D printing enthusiasts can agree that maintenance is the least exciting part of printing. After hours of printing with the Prusa MK4, however, we have learned that maintenance is particularly important to keep these printers running properly. In this guide, we'll share our proven maintenance schedule that keeps Prusa MK4 printers running like new, even in high-throughput environments. Whether you're running a print farm or just want to get the most out of your printer, this approach will save you time and frustration in the long run.

Why Maintenance Matters

Over years of working with print farms, we've discovered that the difference between an endless string of print problems and consistent, reliable performance often comes down to one thing - preventive maintenance. For many of us, our approach to printer maintenance comes from our hobbyist days - fix things when they break. While this might work for occasional printing, it's a costly mistake in production environments. Running a printer until something fails not only risks inconsistent print quality but also leads to unplanned downtime that always seems to happen during your most critical times.

Your MK4 is a precision tool, and small proactive steps save you time and effort. Cleaning a hotend is quick and simple—replacing one after a failure isn’t. Routine maintenance ensures your printer stays reliable and your workload stays manageable, even during critical projects.

Integrated Maintenance: Daily Checks

The secret to consistent maintenance is making it part of your existing workflow. We call this "integrated maintenance" - simple visual inspections you perform while doing things you're already doing, like picking up finished prints or loading new filament.

Every time you interact with your printer, quickly check:

1. Hotend Cleanliness: Look for filament buildup around the nozzle sock. Buildup will cause levelling issues and make your printer print the first layer too high, leading to adhesion problems.

2. Listen for Unusual Sounds: As the printer moves, listen for any grinding or unusual noises from the extruder or axes. These often indicate it's time to clean and re-lubricate your linear rails or re-tension belts.‍
3. Filament Path: Ensure your spool spins freely and the filament mount hasn’t shifted. On the MK4, tight or restricted filament can create tension on the nozzle during bed levelling, causing inaccurate calibration. This can lead to issues like poor first-layer adhesion, uneven extrusion, or even printing in thin air—where the nozzle is too high above the bed to properly deposit filament. Keeping the filament path unobstructed is crucial for accurate levelling and reliable prints.

Weekly Maintenance (or every 200 print-hours)

Prusa recommends maintenance every 200 print hours, and our testing confirms this is the sweet spot. Here's your weekly checklist:

System Checks

Run these built-in tests from your LCD:

• Fan Tests
• X, Y Axis Test
• Heater Check
• Z Alignment Calibration (particularly important for consistent first layers)
• Z Axis Test
• Loadcell Test
• Axes check

Mechanical Inspection

1. Smooth Rods:
   • Check for scratches/grooves by running your fingers along each rod while rotating
   • Use your fingernail to verify any suspicious spots you feel
   • Clean with a paper towel and apply fresh Prusa Lubricant
   • If motion feels rough, clean bearings with alcohol and re-grease with a small amount of Prusa Lubricant

2. Belt System:
   • Remove any debris around pulleys and belts
   • Verify belt pulley set screws are secure on the flat side of the motor shaft
   • Check belt tension - they should sound like a low bass note when plucked

3. Nozzle Care:
   • Inspect nozzle sock for filament buildup
   • Remove sock and check heater block for buildup
   • Replace nozzle if using abrasive or sticky filaments (PETG, Carbon Fiber, etc.)
   • Watch for signs of nozzle wear:
     • Poor bed adhesion
     • Weak layer bonding
     • Inconsistent homing
     • Poor print quality

4. Hotend Check:
   • Verify thumbscrew tightness (finger-tight plus quarter turn with pliers)
   • Confirm heater block is secure - it should not rotate when force is applied
   • Clean both fans thoroughly:
     • Use compressed air to remove dust
     • Use tweezers to remove any plastic threads
     • Verify smooth fan operation

Monthly Maintenance (or every 800 print-hours)

Annual Updates

Slicer Updates

Firmware Review

Making Maintenance Work for You

The key to successful maintenance isn't just knowing what to do - it's making it a habit. We recommend:

1. Creating a maintenance log for each printer
2. Setting calendar reminders for weekly and monthly checks
3. Keeping basic supplies (lubricant, cleaning materials) easily accessible
4. Training all operators on basic maintenance checks

Remember: in production environments, preventing problems is always faster and cheaper than fixing them. While this maintenance schedule might seem extensive, it typically takes less than 30 minutes per week once you're familiar with the process.

Have you established a maintenance routine for your MK4? We'd love to hear about your experiences or answer any questions about implementing these practices.

Looking for more MK4 solutions? Check out our previous posts on fixing mid-air printing, nozzle oozing, first layer issues, and layer shifts.