HMS 0300-0A00-0001-0005: continuous force detected, heatbed may be stuck
LayerWalker is a participant in the Amazon Services LLC Associates Program. We may earn a commission when you buy through links on our site, at no extra cost to you.
HMS 0300-0A00-0001-0005 means force sensor 1 is reporting a continuous load that never releases. The nozzle touch it is supposed to measure comes and goes; a constant reading means something is holding the bed under permanent pressure. Bambu names the likely reason directly: the heatbed may be stuck.
Affected machines: X1 series. The bed hangs on its Z drive and rests on its force sensors. Anything that stops it moving freely, or that loads it from a direction the design does not expect, produces a reading the firmware cannot use.
Where to buy
What actually binds a bed
Debris in the Z path. A failed print that fell behind the bed, a piece of packaging, a stray hex key. Look with a torch before anything else, because this is both the most likely and the easiest to fix.
A dry or dirty lead screw. The screw and nut need a thin film of grease. Run dry and they pick up debris, stiffen, and hold the bed under tension between moves.
Something caught on a cable. A filament tube or a loom that has snagged as the bed travels, pulling it out of square and loading one corner.
Test by hand with the machine off. Move the bed gently through its range and feel for a spot where it tightens. A bed that binds in one place tells you where to look; one that is stiff everywhere points at lubrication.
Levelling fails and the printer reports continuous force, suggesting the bed is stuck
Debris in the Z path, a dry lead screw, or a snagged cable loading the bed
- Power off at the wall and let the bed rest on its stops.
- Look into the Z path with a torch, including behind and beneath the bed, and remove anything you find.
- Move the bed by hand through its travel and note any point where it tightens.
- Check the lead screws. If they look dry or dirty, clean them and apply a thin film of the correct grease.
- Check the cable runs and filament path for anything snagging as the bed moves.
- Power up and run a Z homing cycle, then re-level and watch whether the reading releases normally.
Use grease made for lead screws, not oil and not a spray lubricant. Oil runs off and collects dust, which is how a screw that was merely dry becomes a screw that is gritty.
The external disturbance version is disturbance on force sensor 1. Our page on the lead screw covers lubrication properly, and the troubleshooting index covers the rest.
HMS 0300-0A00-0001-0005 FAQ
Can I force the bed free by hand?
Move it gently to find the tight spot, but do not force it. Find what is holding it instead.
Which grease should I use?
A lead screw grease. Avoid oil and avoid spray lubricants, both of which attract dust.
Could the Z motor be at fault?
Only after you have ruled out debris and lubrication. A motor that has been fighting a bind can fail, but it is rarely the first cause.
Why does levelling fail rather than printing?
Because levelling is where the machine weighs the bed. A constant load makes that measurement meaningless.
LayerWalker
Print defect diagnosis, calibration procedures and parts that actually fit. Corrections welcome through the contact page.
