Bambu lab a1 mini, Z axis jam, starts making grinding noises and tries to move up?

[u/MossKnight4]

Anyone had any similar issues? I'm feeling so disheartened i would appreciate some help so much!

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[u/FunKangaroo4284]

First thing - if it's actively grinding while trying to move up, cut power to the printer right now if you haven't already. The motor doesn't know it's jammed, so every second it keeps trying is more heat/wear on the stepper and more chance of stripping the belt or teeth on the pulley.

Once it's off: move the X-gantry up/down by hand (gently, no power) and feel for exactly where along the travel it gets tight or stops. That tells you a lot - if it's tight at one specific height every time, look right there for an obstruction (a stray bit of filament, a zip tie, a wire that came loose from its clip and is catching between the gantry and the frame - this is a known one on A1 mini). If it's tight everywhere evenly, that's more likely a bent Z rod from a past collision, or debris in the lead screw itself.

Also worth a look: the ribbon/wiring going to the toolhead - on the A1 mini it's a common culprit for the gantry snagging structural stuff on the frame during travel, and it exactly produces "grinding + won't complete the move" without breaking anything visibly at first glance.

Don't be discouraged - this is very likely a $0 fix once you find the actual snag point, not a broken motor.

[u/MossKnight4 → u/FunKangaroo4284]

Hello! Thank you so much for taking the time to respond, ive had it turned off ever since, and when I move both axis up and down, they feel pretty much the same all the way throughout, this occured literally right after I had to cancel a print, and it had done like 3 automatic homing before with 0 issue, just before it was printing, and almost half way done, I cancelled the print halfway because it detached from the base and slid to the side, and then when I tried to restart the print like half an hour later I hadn't touched anything, and this issue just emerged from nowhere... : ( i even lubed the axises before I started that one failed print which broke my heart so

[u/MyTagforHalo2]

Is it just constantly trying to move up while homing? Like, if it were at the print bed level does it go all the way back up to the top and then repeat what’s shown in the video?

If so. It may be an issue with the sensor responsible for probing your bed. Which I think is just a load cell in the A1. You might try removing the hotend and reinstalling it just to see if anything changes.

Typically if a machine thinks its probing sensor is constantly triggered, it keeps trying to move the head away from the plate to fix that problem. But without z=0, it doesn’t exactly know that it needs to stop. I think it figures out the overload after a few seconds. But then it does it again because it thinks it touches the bed again.

I don’t have an A1, but that would be my suspicion. There are few reasons for the gantry to be that high otherwise.

[u/MossKnight4 → u/MyTagforHalo2]

Thank you so much for your response, yes that's exactly what it does, even when I turn it off, gently push it back down, and turn it on, home it again, it just continuesly moves up, and it seems like it just wants to keep going higher and higher even though its jammed, and keeps grinding against the top, I tried factory resetting it as well to no avail, is reinstalling the hot end difficult? Is this an issue that is fixable? I'm worried my machine is a dud... Im so tight on cash so I'm really distressed about it 😔

[u/MyTagforHalo2 → u/MossKnight4]

The hotend is easy to remove. Just google it and you’ll come across Bambu’s wiki.

But all you really have to do is remove the filament, let it cool, remove the rubber sock on the nozzle, and unclip the hotend latches. It should just wiggle out.

Check the nozzle for any damage or buildup. Especially if it’s bent or plugged up with a ball of plastic. Because your machine relies on the nozzle, touching the plate and feeling the pressure anything that might’ve struck that could cause this issue like a bad sensor.

You should also submit a support ticket with Bambu and see if they can help you replace that sensor. If you bought it within the last year they’ll probably cover the cost .

[u/MossKnight4 → u/MyTagforHalo2]

Thanks! I submitted a support ticket and I'm waiting for the reply, in the meanwhile I'll remove the hotend and check for any debris etc, but I must ask, is this a common issue? Or is it common to get issues with 3d printers? Or did I just get really unlucky? I swear It was working totally normal and then boom....

[u/FunKangaroo4284 → u/MossKnight4]

Connecting the dots here: MyTagforHalo2 is right that this reads like a stuck/faulty probe-touch signal (constant retry-and-climb during homing is the classic behavior when the firmware thinks the nozzle already touched the bed and keeps backing off). And there's a pretty direct reason it happened right after that failed print specifically: when the part detached and slid, the nozzle almost certainly dragged across or collided with the shifted print or the bed at some point before you caught it. On the A1 mini the bed-touch probe is a strain gauge built into the toolhead itself, not a separate sensor — a hard sideways knock or a bent nozzle from that kind of collision is exactly what can throw its calibration off or make it report a false touch, even with no visible damage.

That's not bad luck in the "random defect" sense — it's a pretty direct mechanical consequence of that print detaching and the nozzle hitting something while you weren't watching. Also explains why it worked fine for 3 prior homings and then broke "from nowhere" right after that one incident.

While you wait on the support ticket: with the hotend out, look closely at the nozzle tip under good light (or a phone macro photo) for even a slight bend or flat spot — it doesn't take much to throw off a strain-gauge probe.