Kobra S1: noise from the Z axis, the rods or the print head while printing

Symptom

The Kobra S1 makes noise when the Z axis moves, the print head catches or drags as it moves, there is a rubbing sound at the top while printing, or it is very loud while preparing a print.

Likely causes, from most to least likely

1. The Z-axis lead screw needs maintenance: cleaning and grease roughly every three months.
2. Dirty rods: dust, filament debris or no grease on the Y-axis rods, or dirt on the X-axis rods.
3. The print head cable or the PTFE tube rubs against the top cover when the print head reaches some extreme positions.
4. Normal noises: metal friction when printing above 350 mm/s, and the vibration compensation calibration while preparing a print, which sweeps through frequencies and is louder.

Checks to tell which one it is

• Move only the Z axis from «Tools» → «Move» and listen for whether the noise comes from the lead screw.
• With the printer off and unplugged, move the Y axis by hand: look for dust or debris on the rods and feel for resistance or catching.
• Note whether the noise only happens during vibration compensation or when printing above 350 mm/s: in those cases it is normal.

Before you start

Before taking anything apart, cleaning or adjusting it, switch the printer off and unplug it, unless a step says otherwise, and do not touch the nozzle, the heater block or the bed until they have cooled down. If in any doubt about electricity, heat or moving parts, stop and ask a professional.

Step-by-step fix

1. Clean and grease the Z lead screw

   Clean the Z-axis lead screw with a lint-free cloth. Switch on and, in «Tools» → «Move», tap «Z Zero» to raise the platform to the top; apply a little grease along the lead screw. Lower the platform with «Z+» to the bottom, apply a little grease again and tap «Z Zero». Use grease, not oil: oil runs down the lead screw.

   Check: In a few test prints the Z axis moves smoothly and quietly.

   If that does not fix it: Check the Y-axis rods (next step).

2. Clean and grease the Y-axis rods

   Switch off and unplug. Remove dust and debris from the Y-axis rods with a lint-free cloth or a soft brush; if you use air, blow gently so you do not push dust into the electronics. Apply a little grease along the rods and move the axis to spread it.

   Check: When you push and pull the print head by hand there is no catching or play.

   If that does not fix it: Check the X-axis rods (next step).

3. Clean the X-axis rods, without grease

   If the X-axis rods are dirty, wipe them with a lint-free cloth and a little alcohol. Do not grease them: they run on graphene bearing sleeves, which are self-lubricating.

   Check: The print head moves smoothly along the X axis.

   If that does not fix it: Check the print head cable and tube (next step).

4. Cable and tube rubbing on the cover

   If the noise is a rubbing at the top when the print head reaches the extremes, reposition the PTFE tube and the print head wiring harness so they do not touch the top cover.

   Check: The rubbing stops.

   If that does not fix it: If it continues, contact Anycubic support with a video of the noise.

5. Vibration compensation only when needed

   The loud noise of the vibration calibration while preparing a print is normal. The option is unticked by default in the print preparation: tick it only after moving the printer or changing parts of its structure, not for every print.

   Check: In normal prints you no longer hear that sweep.

   If that does not fix it: If the noise also happens while printing, go back to the previous steps.

Prevention

• Maintain the Z lead screw about every three months, with grease, not oil.
• Check once a month that the Y-axis rods are clean.
• From time to time, clean the dust off the hotend, front cover and auxiliary fans.

Still not fixed?

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Printers it applies to

Anycubic Kobra S1.

Official sources

This guide summarises the official documentation linked here:

• Kobra S1 Maintenance Recommendations · Anycubic
• Kobra S1 Combo FAQ · Anycubic