Bambu Lab HMS error code 0300-0600-0001-0002 is a Y-axis motion fault within the 0300-0600 motion system subgroup. The printer detected that the Y-axis — controlling forward and backward movement of the toolhead or bed depending on the printer model — did not respond as expected to a commanded motion.

What the Error Means

Like other motion faults in the 0300-0600 family, suffix 0001-0002 signals a Y-axis stall detection event or unexpected motion resistance. The Y-axis is subject to the same mechanical wear as other axes: belt stretch, rail contamination, pulley loosening, and lubrication degradation. Because the Y-axis carries the weight of the gantry or bed, it can be more sensitive to lubrication issues than the X-axis.

Step-by-Step Fix

1. Power off the printer. Manually push and pull the Y-axis through its full range of travel. Smooth, effortless motion throughout the entire range is expected. Note any spots where resistance increases.
2. Clean the Y-axis linear rods, rails, or lead screws (depending on your printer model) with a clean lint-free cloth to remove dried lubricant or accumulated debris.
3. Apply fresh lubricant as specified in the Bambu Lab maintenance guide. Distribute evenly and move the axis through its range to spread the lubricant.
4. Check Y-axis belt tension. The belt should have consistent tension and not slip on the pulleys. Adjust the belt tensioner if the belt feels slack.
5. Inspect the Y-axis motor pulley for a loose set screw. A slipping pulley can cause the axis to fail to reach commanded positions, triggering stall detection.
6. Look underneath the print bed or along the Y travel path for any obstruction — a stray tool, filament fragment, or shipping foam that may have been overlooked.
7. Run the printer’s homing sequence or auto-calibration and observe whether the Y-axis completes without error.

Parts Required

• Lubricant (appropriate grade per Bambu Lab documentation)
• Hex key set for set screw adjustment
• Y-axis belt if worn or stretched beyond spec

If the fault recurs after mechanical attention, contact Bambu Lab support for motor driver diagnosis.