FIG.1 / LAYER SHIFT, WHERE TO LOOK 1 1 BELT TENSION 2 2 SPEED / ACCELERATION 3 3 CARBON RODS CLEAN 4 4 Z-HOP + COLLISIONS
Shifts are mechanical until proven otherwise: belts, speed, rods, then electronics.
Step 1 of 5
1
Most likely fix

Check belt tension

Pluck the belt like a guitar string, a dull thud means too loose, a high ping means too tight. Go to Settings ? Calibration ? Vibration Compensation, target: 110–150 Hz.

Also check for visible cracks or missing teeth. Damaged belts lose tension unevenly and cause sporadic shifts.

2
Collisions

Enable Z-Hop

In Bambu Studio: Quality ? Travel ? Z-Hop, set to 0.3–0.5 mm. The print head lifts during travel moves and avoids collisions with curled edges or warping corners.

Nozzle collisions are the second most common cause, especially when the first layer has an elephant foot.

3
Speed

Reduce print speed

Reduce print speed by 20–30% and test again. Very high acceleration forces can exceed motor torque and cause missed steps.

Also reduce acceleration and jerk values if they were manually increased.

4
Mechanics

Clean the carbon rods

Dirt on the guide rods increases friction and causes missed steps. Clean the rods with 99% IPA and a lint-free cloth, then lubricate with PTFE dry spray.

Also check whether the printhead cable bundle catches anywhere when moving across its full range.

5
Advanced

Less common causes

If all mechanical causes have been ruled out, electrical issues may be to blame. Expand the topic that matches your situation:

Shift only in X: X-belt, X-belt pulley, or X-motor. Shift only in Y: Y-belt, Y-belt pulley, or Y-motor. Shift in both directions at once points to overheating, power supply issues, or very high acceleration.

Reseat all stepper motor cable connections. Make sure the printer is well-ventilated, overheated motor drivers lose torque. Voltage drops under load can also cause missed steps; run the printer from a stable outlet.

Worn linear bearings cause grinding noises and intermittent binding. Push the printhead manually across its full range with the printer off. It should glide smoothly with no jerking or resistance.

Check belt tension monthly. Clean carbon rods every 3 months. Keep speed within rated values. Enable Z-Hop for sticky materials. Monitor the first layer for over-extrusion.

Problem solved!

Bookmark this page for next time.

Tools that fix this

Free the motion system and torque the mechanics back down.

ZDBB Silicone Grease
ZDBB Silicone Grease
~$10

Silicone grease for the Z lead screws and rails: dry, sticky motion makes the toolhead bind and skip steps; lubricated axes move freely and stay in sync.

Amazon →
WERA Hex-Plus Set
WERA Hex-Plus Set
~$25

Loose belt-idler and pulley grub screws cause shifting; these hex keys let you re-tension and tighten them without stripping.

Amazon →

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Nothing worked?

Post your case in the community forum, photos help a lot, and we answer within a day. Or try the interactive troubleshooter.

HMS codes that point here

If Bambu Handy or Bambu Studio shows one of these HMS codes, it maps to the problem on this page. Each code links to Bambu's official step-by-step fix; come back here if the official steps don't solve it.

  • HMS_0300-1000-0002-0001 – X-axis resonance frequency low, timing belt may be loose · official fix
  • HMS_0300-1000-0002-0002 – X-axis resonance differs from last calibration (clean carbon rods) · official fix
  • HMS_0300-1100-0002-0001 – Y-axis resonance frequency low, timing belt may be loose · official fix
  • HMS_0300-0600-0001-0001 – Motor open-circuit, loose connection or failed motor · official fix