Maintenance
Routine maintenance procedures and checklists.

Prusa MK4 Maintenance
Regular maintenance checklist for the Original Prusa MK4 (Nextruder). It follows Prusa's own guide: Regular printer maintenance (MK4/S, MK3.9/S).
How often
Interval
What
Before every print
Some items; see Prusa's guide linked above
Every 200 print hours
Axes (rods and bearings), belts, fans and the Nextruder (sections 2 to 8)
Yearly, or every 600 to 800 print hours
Electronics check (section 9)
Supplies
Prusa Lubricant (Prusa Lubricant Applicator Set)
Isopropyl alcohol (IPA) and paper towels
Compressed air, small brass brush, tweezers, toothpick
Allen keys, needle-nose pliers
Acetone (Smooth PEI sheet only)
Do not lubricate the Z-axis lead screws or trapezoid nuts. Do not open the Nextruder gearbox unless Prusa support asks you to; the primary gear and idler bearings need no lubricant.
1. Before you start
Note the print hours and firmware version so they can be logged with the maintenance.
Unload filament.
Clear any maintenance warning on the screen and note what it said (Maintenance warning reference).
2. General cleaning and hotend
Brush or vacuum debris from the frame and under the heatbed.
Heat the nozzle to 250 °C for 3 to 5 minutes, then scrub old plastic off with a brass brush. Keep the brush off the hotend cables.
Let it cool for about 10 minutes, and confirm the temperature on the display before touching it.
3. Hotend thumb screws and nozzle seating (printer off and cold)
Hand-tighten the hotend thumb screws (no tools).
Confirm the nozzle has no vertical play and the heater block does not rotate.
If a Nozzle Adapter is installed, confirm the nozzle is not lowered or loose (Nextruder V6 Nozzle Adapter).
4. Smooth rods and bearings (X, Y, Z)
Roll each rod between your fingers to feel for grooves or scratches.
Wipe each rod clean with a paper towel.
Apply a small amount of Prusa Lubricant and run each axis end to end several times.
Only if an axis still feels rough: remove the bearings, clean them with IPA, and regrease the inside with a small amount of Prusa Lubricant. A printable LM8UU bearing greasing adaptor makes this easier.
5. Belts and pulleys
Remove debris around the pulleys and belts.
Confirm each pulley set screw is tight on the flat of the motor shaft.
Pluck the X and Y belts: they should give a low bass note.
Measure and adjust tension per Adjusting belt tension (MK4/S, MK3.9/S, MK3.5/S, MK3/S/+), which covers the frequency method used on the MK4. Note the upper, lower and Y readings.
6. Fans
Hold each propeller still and blow it out with compressed air. Never blow air into a running or free-spinning fan.
Remove plastic threads with tweezers.
Never bypass the fan RPM check. A slow fan throws an error on purpose.
7. Nextruder (drive gear area)
Lift the idler nut and swing the idler out.
Clear filament dust from the primary gear grooves through the side access hole (compressed air, brass brush or toothpick).
Close the idler and reset the tension.
If extrusion or hotend problems persist, see Changing or replacing the Nextruder hotend and How to rebuild the Nextruder hotend.
8. Print sheets
Clean each sheet with IPA; use dish soap and warm water for a deeper clean (Print surface preparation).
Acetone only on the Smooth sheet, never on Textured or Satin. Never use alcohol or acetone on the PA Nylon sheet (Flexible steel sheets guidepost).
9. Electronics (yearly, or every 600 to 800 hours)
Power off and unplug the printer.
Check and reseat the connectors on the xBuddy board, Loveboard, heatbed, PSU and xLCD.
Confirm screw-terminal connectors are fully tight.
For Molex connectors, press the latch before pulling.
10. Firmware
Update to the latest stable MK4 firmware if it is behind (download from Prusa's MK4 firmware page; install from a USB drive).
11. Recalibrate
Run Selftest / Calibrations & Tests from the printer menu.
Run the Loadcell Test (Control > Calibration & Tests > Loadcell Test). If it fails, see Loadcell troubleshooting; overtightened Nextruder bolts are a common cause.
Confirm Input Shaper is enabled and that the slicer uses the Input Shaper profile (Input Shaper article).
Print a small test part. The first layer is auto-calibrated by mesh bed leveling through the load cell, so just inspect it.
Afterwards
Record anything you found, what you did about it, and whether follow-up is needed. If the printer is not safe to use, tag it out of service: see Shop Safety: Tagging a Tool Out of Service and Reporting It.

Prusa MK3S+ Maintenance
Regular maintenance checklist for the Original Prusa i3 MK3S+. If there is more than one MK3S+, go through the whole checklist for each printer. It follows Prusa's own guide: i3 Printer Regular Maintenance.
How often
Interval
What
Every couple hundred print hours
Cleaning, axes, belts, extruder, fans, sheets (sections 2 to 7)
Every 600 to 800 print hours, or at least yearly
Electronics check (section 8)
Supplies
Prusa Lubricant (Prusa Lubricant Applicator Set). Acceptable alternatives per Prusa: Super Lube synthetic grease, GLEIT-µ HF 400, Mogul LV 2-EP. Avoid very high viscosity grease.
Isopropyl alcohol (IPA) and paper towels
Compressed air, small brass brush, tweezers, cotton swabs
Allen keys, needle-nose pliers
Acetone (Smooth PEI sheet only)
Do not lubricate the Z-axis lead screws or trapezoid nuts. Prusa explicitly warns against this.
1. Before you start
Note the print hours from LCD > Statistics.
Unload filament.
Note the firmware version under LCD > Support (you will compare it in step 10).
2. General cleaning
Brush or vacuum filament bits, dust and broken supports from the frame and under the heatbed.
Heat the nozzle and brush off old plastic with a brass brush. Keep the brush off the thermistor and heater wires.
3. Smooth rods and bearings (X, Y, Z)
Roll each smooth rod between your fingers and feel for grooves or scratches. Note any damaged rods.
Wipe each rod clean with a dry paper towel.
Apply a thin film of Prusa Lubricant to each rod and run the axis end to end several times (Prusa maintenance tips guide).
If an axis still feels rough, remove the bearings, clean them with IPA, and grease the inside with a pea-sized amount (bearing maintenance article).
Check that the X-carriage-back screws and Y-bearing U-bolts are snug but not overtightened. Overtightening deforms the bearings and scratches the rods.
4. Belts and pulleys
Clear debris from the belt pulleys and idlers.
Confirm each pulley grub screw is tight against the flat of its motor shaft.
Pluck the X and Y belts: they should give a low bass note.
Check LCD > Support > Belt status. Target values are 260 to 290.
Adjust if out of range: Adjusting belt tension (MK4/S, MK3.9/S, MK3.5/S, MK3/S/+).
5. Extruder (Bondtech gears and idler)
Open the idler door (one screw on the MK3S+).
Cover the PTFE tube entry with a cotton swab, then clean both Bondtech gears with a brass brush, rotating a few degrees at a time through a full turn. Blow out the debris.
Verify the drive gear is aligned with the filament path and its grub screw is tight (Checking/re-aligning the Bondtech gear).
Confirm the idler shaft and bearing spin freely.
Optional: a tiny amount of non-oil grease on the outward-facing gear teeth only. Keep it off anything that touches filament.
Check idler screw tension: the head should be roughly flush with the extruder plastic (Idler screw tension).
6. Fans
Hold each propeller still and blow out dust with compressed air. Never spin a fan with air.
Remove plastic strings with tweezers.
Confirm the hotend fan and the print (part cooling) fan both spin freely by hand.
7. Print sheets
Clean each steel sheet with IPA; use dish soap and warm water for a deeper clean.
Acetone only on the Smooth PEI sheet, never on Textured or Satin (Flexible steel sheets guidepost).
Note any sheets with gouges or worn coating.
8. Electronics (every 600 to 800 hours, or at least yearly)
Power off and unplug the printer.
Inspect cables for pinching, rubbing or worn insulation, especially the heatbed cable bundle.
Blow dust out of the Einsy electronics enclosure.
Gently tug-test the PSU and heatbed power connectors, and retighten any terminal screws that move (Einsy RAMBo wiring reference).
9. Nozzle
Inspect the nozzle for wear (rounded tip, enlarged hole) or damage.
Replace it only if print quality stays poor after everything above (Changing or replacing the nozzle).
10. Firmware and slicer
Update to the latest stable MK3S+ firmware if it is behind (How to update firmware MK3S+).
Confirm the shop computers have a current PrusaSlicer.
11. Recalibrate
Prusa recommends recalibrating after maintenance.
Run Selftest from LCD > Calibration (fans, axes, heaters).
Run XYZ calibration if bearings, rods or the frame were disturbed (XYZ calibration MK3/MK3S). If the nozzle catches the paper, the SuperPINDA may need to be lowered slightly.
Run First layer calibration and set Live Z for each sheet in use (Basic calibration articles).
Print a small test part and inspect the first layer.
Afterwards
Record anything you found, what you did about it, and whether follow-up is needed. If the printer is not safe to use, tag it out of service: see Shop Safety: Tagging a Tool Out of Service and Reporting It.

Bambu Lab X1C and AMS Maintenance
Maintenance checklist for the Bambu Lab X1 Carbon printer and its two filament units, the AMS 2 Pro and the original AMS (Gen 1). It follows Bambu Lab's guides:
Bambu Wiki: X1 Basic Maintenance
Bambu Wiki: AMS Basic Maintenance
Bambu Wiki: AMS 2 Pro hub
X1 Series Regular Maintenance Manual (ManualsLib copy)
How often
Interval
What
Every 3 to 5 days if ABS is printed often
Clean the Micro Lidar window
Every 2 weeks
Check AMS desiccant and humidity
Monthly (every 5 rolls if printing ABS/ASA)
Clean carbon rods and re-tension belts
Every 2 months (monthly with abrasive filaments)
Replace AMS PTFE tubes
Every 3 months
Grease Z lead screws; replace the activated carbon filter under heavy use
As needed
Nozzle wiper, nozzle, silicone sock, build plates
Supplies
IPA (90% or stronger) and lint-free or microfiber cloths
Grease for the Z lead screws (Bambu suggests Super Lube 92003 or Lucas 10533, or the grease from the Bambu accessory box)
H2.0 hex key and the X1 accessory box tools
Compressed air, brass brush, tweezers
Spare nozzle wiper, spare PTFE tube (4 mm OD), fresh desiccant if available
Do NOT grease the X-axis carbon rods. Grease causes abnormal resistance and makes cleaning harder; the bearings are self-lubricating. Power off and unplug the printer before any mechanical work.
X1C printer
1. Before you start
Unload filament from the AMS units.
Note the firmware versions (printer, AMS 2 Pro, AMS) in Bambu Studio or Bambu Handy.
2. General cleaning
Vacuum or brush debris from the chamber floor, bed area and purge chute.
Empty and clean the purge waste bin area.
3. Carbon rods and belt tension (do these together)
Procedure: Bambu Wiki: Carbon rods clearance and cleaning
Loosen (do not remove) the four belt tensioner screws at the back of the printer.
Press on the belts next to the toolhead and confirm the tensioners move.
Wipe each X-axis carbon rod with IPA on a lint-free cloth. Repeat 2 to 3 times until the cloth comes away clean.
Move the toolhead to the center of the build area and retighten the tensioner screws. This re-tensions the belts.
With the printer off, move the toolhead by hand from corner to corner. Motion should be smooth with no grinding.
4. Z-axis lead screws (every 3 months)
Wipe dust and plastic off all three Z lead screws.
With the bed homed (at the top), apply a thin coat of grease.
Lower the bed, apply another thin coat, and home again. Repeat a few cycles to spread it.
Wipe off excess grease that builds up near the lead screw nuts. Too little is better than too much.
5. Nozzle wiper
Check the wiper for filament debris and a damaged PTFE side. It must sit horizontal.
Replace it if the plastic structure is deformed or cracked, or if it slips (Bambu nozzle wiper part).
6. Hotend and extruder
Heat the nozzle and brush residue off the nozzle and heater block. Inspect the silicone sock and replace it if torn.
Do a cold pull if there are any signs of partial clogging (see the X1 nozzle clog troubleshooting page on the Bambu Wiki).
Inspect the nozzle tip for wear, especially if carbon fiber or glow-in-the-dark filaments have been run on the stock nozzle.
Open the extruder idler and brush filament dust from the drive gears.
7. Micro Lidar
Clean the Lidar window with IPA on a microfiber cloth.
8. Activated carbon filter and fans
Check the carbon filter. Replace it about every 3 months under heavy use (Bambu Wiki: Replace the activated carbon air filter).
Blow dust out of the part cooling fan, auxiliary fan and chamber fan. Hold the blades still.
9. Build plates
Wash each plate with warm water and dish soap, and dry it fully.
Note any worn or scratched plates.
10. Cables and PTFE path
Check the toolhead cable and flat ribbon cable for kinks or wear.
Inspect the PTFE tube from the AMS hub to the toolhead for wear or kinks.
AMS 2 Pro and AMS (Gen 1)
11. PTFE tubes
Inspect all AMS PTFE tubes (slot to hub, and hub to printer) for wear grooves, kinks or loose ends.
Replace them about every 2 months under normal use, or monthly if printing abrasive filaments (carbon fiber, glow-in-the-dark).
Confirm every tube is fully seated in its connector.
12. Feeders and filament path
Remove any broken filament pieces from the feeders and hub. Pushing a good, non-brittle piece of filament through the first-stage feeder pushes debris out.
Check the feeding funnels for wear. Replace them if badly worn and causing feed or retract errors.
AMS 2 Pro: clean the filament hub per Bambu's hub cleaning guide (AMS 2 Pro hub). If a feeder needs replacing: Replace feeder unit.
AMS Gen 1: check that the spool rollers and support shafts spin freely, and clean dust off the rollers.
13. Desiccant and humidity
Check the desiccant and humidity indicator in both AMS units. Dry or replace the desiccant as needed.
Confirm the lids seal.
14. AMS test
Load one spool in each slot of both units and run a load and unload on every slot.
Run a short multi-material print that pulls from both AMS units.
15. Recalibrate the X1C
Power on and run the full Calibration from the printer screen (bed leveling, vibration compensation, motor noise cancellation, Micro Lidar).
Update firmware for the printer and both AMS units if they are behind.
Print a small test part and inspect the first layer.
Afterwards
Record anything you found, what you did about it, and whether follow-up is needed. If the printer is not safe to use, tag it out of service: see Shop Safety: Tagging a Tool Out of Service and Reporting It.

Anycubic Kobra 2 Max Maintenance
Maintenance and troubleshooting checklist for the Anycubic Kobra 2 Max (V-wheel gantry, belt tensioner knobs, auto leveling). Sources:
Anycubic Wiki: Kobra 2 Max Leveling Calibration Guide
Anycubic Wiki: Kobra 2 Series Quick Start Guide
Anycubic Wiki: Firmware update log
History: this checklist was first written to bring this printer back into service, so it starts with a diagnosis step. Use that step whenever the printer is acting up; otherwise follow the routine schedule.
Confirm the model on the label on the back. This page is for the Kobra 2 Max. The older original Kobra Max is mechanically similar but its menus differ; see Anycubic: Kobra Max hot end replacement.
Routine schedule
Interval
Task
Before each print
Clean the bed; check the nozzle for buildup
Monthly
Check eccentric nuts and belt tension; clean the V-slots
Every 3 months
Grease the Z lead screws; clean the extruder gears; blow out the fans
As needed
Nozzle replacement; firmware updates
Supplies
Open-end wrenches (for the eccentric nuts), hex keys
Isopropyl alcohol (IPA) and paper towels
Light machine grease for the Z lead screws (PTFE-based, for example Super Lube)
Compressed air, brass brush
Spare nozzle (check the fit: Kobra 2 nozzles differ from standard Volcano nozzles), USB drive or SD card for firmware
Known-good PLA
1. Diagnose (when something is wrong)
Write down the symptom: will not power on, heater or thermistor error, leveling failure, poor prints, clog.
Power on and note any error message.
Heater or thermistor (NTC) errors usually mean a loose cable or a failed part. Reseat the connectors first (see the troubleshooting section of the Quick Start Guide).
2. Power off, unplug and clean
Remove debris from the frame, bed and V-slot extrusions.
Wipe the V-slot channels so the wheels roll on clean aluminum.
3. Frame and fasteners
Check that the gantry uprights are square to the base and all frame bolts are tight.
Shake the print head and the bed by hand to find any wobble.
4. V-wheels and eccentric nuts
Loose or worn wheels are the most common cause of Kobra problems.
Lower the X-axis module (pull the belt) and check the Z-axis V-wheels for slipping.
For any loose carriage (Z, X print head, Y bed), turn its eccentric nut with an open-end wrench in small steps until the wheel just stops spinning freely under your finger, without binding.
Every wheel should touch the extrusion; none should be so tight that it flat-spots.
Look for cracked, flat-spotted or worn wheels and report them for replacement.
5. Belts
Inspect the X and Y belts for fraying or missing teeth.
Anycubic's method: turn the X/Y tensioner knob fully clockwise, then back it off two turns counterclockwise.
Confirm the pulley grub screws are tight on the motor shafts.
6. Z-axis lead screws
Wipe the lead screws clean.
Apply a thin coat of light grease, run Z up and down to spread it, and wipe off the excess.
Confirm both Z sides move together, so the gantry stays level.
7. Extruder and hotend
Heat the nozzle and brush off old plastic.
Open the extruder and clean filament dust from the drive gears.
Do a cold pull, or replace the nozzle, if extrusion is weak or blocked.
Check the heater cartridge and thermistor wires at the hotend for damage.
8. Fans and wiring
Blow out the hotend and part cooling fans. Hold the blades still.
Inspect the print head cable and bed cable for wear at the bend points.
With the printer unplugged, reseat the main board connectors (heater, thermistor, motors, endstops and probe).
9. Bed surface
Clean the PEI spring steel sheet with IPA, or dish soap and water if needed.
Clean debris off the bed underside and the magnet surface.
10. Firmware
Check the installed version against the Anycubic update log and the Kobra 2 Max firmware page. Only flash official Kobra 2 Max firmware.
11. Calibration
Per the Anycubic leveling calibration guide:
Position calibration: Tools > Control > Module Calibration > Position Calibration. Jog the nozzle to the center of the calibration module, then save.
Auto leveling: Tools > Control > Auto Leveling, with the bed heated.
Z-offset: print a first-layer test and adjust the Z-offset until the line is slightly squished.
Print a small test part.
12. If it still will not level or print
Re-check the eccentric nuts and belts (sections 4 and 5). Anycubic attributes most leveling problems to loosened parts.
Check the probing and offset switch area for dust (a community-reported fix for the Kobra 2 family; see Anycubic Kobra 2 leveling issues fix).
Record the problem. If a part has failed, the printer may need a support ticket with Anycubic.
Afterwards
Record anything you found, what you did about it, and whether follow-up is needed. If the printer is not safe to use, tag it out of service: see Shop Safety: Tagging a Tool Out of Service and Reporting It.