HMS 0300-0A00-0001-0003: Heatbed Force Sensor Sensitivity Too Low
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HMS 0300-0A00-0001-0003 means the sensitivity of one of the heatbed force sensors is too low. Contact is detected late or not at all, so the nozzle presses into the plate before the machine registers a touch. That is the direction that marks plates.
A sensor that reads nothing is better than one that reads wrongly, but neither gets you a first layer.
Where to buy
Clean the contact surfaces, not the plate top
Force travels through a clamped stack, and a film of grease or purge between the layers absorbs it. Lint-free cleanroom wipes on the mating faces are the right tool here, because paper leaves fibres in exactly the joint you are trying to make solid.
Lift stuck-on purge off the plate underside
Material welded to the underside of the plate holds it off its seat and softens every reading. A plastic razor scraper takes it off without gouging, and plastic is the point: a steel blade on a plate seat leaves a high spot that is worse than the purge was.
Keep your fingers off the mating faces
Skin oil on a clamped joint is enough to change how force transfers, and it is invisible. Nitrile gloves for the five minutes you have the plate off cost almost nothing and remove a variable you cannot see afterwards.
Then check the stack is actually tight
Low sensitivity often means a loose sensor rather than a dirty one. Snug and even, not tight: the sensors need preload to transmit force, and a screw backed off a turn puts one of them to sleep.
How HMS 0300-0A00-0001-0003 differs from its mirror code
Too high is HMS 0300-0A00-0001-0001 and means something is pressing on the bed already. Too low means force is not reaching the sensor. Same hardware, opposite causes, and the message tells you which.
What it looks like in a print
A squashed, glossy first layer, or a nozzle that drags and leaves a mark. The symptoms are covered in first layer not sticking, and the sensing chain in bed levelling sensors.
HMS 0300-0A00-0001-0003 FAQ
Is the sensor broken?
Not usually. A dirty or loose clamped joint explains most of these.
Should I tighten the screws hard?
No. Even and snug. Maximum torque distorts the stack and swaps the fault, which is HMS 0300-0A00-0001-0001.
Why does it damage plates?
Because the nozzle keeps descending until the sensor finally reacts.
Can I print meanwhile?
Not well. Fix the sensing before you waste filament on it.
LayerWalker
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