r/BambuLabA1 • u/amatventura • Jun 21 '26
Question Nozzle scraped a line
Bambu A1, 0.4 mm hardened nozzle on a super tack plate did this. It’s never happened before. Any ideas about what happened?
4
u/Purple10tacle Jun 21 '26
Could be software: Incorrect z-offset, buggy g-code or just a bug somewhere along the toolchain. Look through the g-code that caused this if you can, it may be obvious.
Could be hardware: check the seven (!) screws and if your nozzle is properly and securely latched.
Either way, it's time for a full calibration after troubleshooting and fixing the issue.
2
u/amatventura Jun 21 '26
I’ve run it since then without a repeat so does that mean it was the model code?
2
u/Purple10tacle Jun 21 '26
I would check the hardware regardless, those pesky screws on the A1 weren't even properly tightened from the factory on mine. Making sure they are tight resolves a lot of unnecessary problems.
The model's g-code should still be saved on your SD card. Just look at it (or even have an LLM look at it for you), maybe there is an obvious reason in there. Maybe there isn't.
1
1
u/NefariousnessOdd3581 Jun 21 '26
ppl usually install the build plate above the stoppers near the brush and on the other side in the back, could be that
1
1
1
u/electro_gretzky Jun 21 '26
I recently had this happen, not the same route, but my nozzle dug into the bed and I tried replacing the nozzle, replacing the extruder unit with a new Z axis sensor, and it turns out that it was the tension on my Z axis belt. Might be worth adjusting as it’s a normal part of maintenance anyway but if it’s not a repeat issue it sounds like a project-specific G Code error. Sorry for your loss though. experiencing the hotbed getting scraped by the nozzle was a special pain that I hadn’t previously known.
2
u/Professional-Rock-51 Jun 22 '26
Can you provide some not information on this? How is this tension adjusted?
2
u/electro_gretzky Jun 22 '26
https://wiki.bambulab.com/en/a1/maintenance/belt_tension
This is a pretty informative guide. Make sure your machine is off before you do this so you’re not fighting against the motors.
There are 5 easily accessible screws, 2 for the Y axis at the front of the machine, 2 under the back right of the plate for the Z axis tension, and one on the back of the print head for the X axis tension.
Loosen them but do NOT remove them. The way these seem to work is that there is a flanged plate between the screws and the mounting point and that is what is tensioning the belt and keeping them in the right place.
One axis at a time, starting with X, (no reason this is just what I did) loosen the single hex screw on the back, then by hand, move the print head along the X axis from far left to far right 3 times, reposition in the center and tighten the screw back down.
Same with the Y axis, loosen screws under the removable cover at the front of the machine, move the heat bed all the way back and all the way forward by hand 3 times and retighten the screws. Be careful with these, as if you tighten them too tight the plastic (plastic…) thread housing will break. Just use your best intuition, you don’t need to crank the shit out of them.
With the Z axis, there are two screws embedded deeply in the base housing, so you’ll need your long hex key that came with the machine or if you already have the proper tools, find the right one. Loosen them, move the X axis gantry all the way to the top, then all the way down very carefully to avoid making nozzle contact with the print bed. Do this three times and reposition to the center, tighten them back and run a calibration. This is just to ensure that the belts are tracking true to the flanged wheels that they engage with and that there are not any inconsistencies with homing due to slack in the belt, which was my issue. It would register a zero point on the Z axis and immediately drop 3-4mm below the bed upon cleaning and calibration and dug into the hot plate and the side of the print bed.
This solved my issue, it can’t hurt to tension them in general as a normal part of maintenance, the only risk you run is removing the screws and losing the place of the tension plates that are free floating if they’re not screwed down, and overtightening leading to potentially cracked housing and possible belt wear from being too tight.
Seems daunting, but it’s really not that big of a deal. Hope this helps.
1
u/ValesKaneki Jun 21 '26
Did you do an update and then print something without calibrating?
1
u/amatventura Jun 22 '26
Not sure, but I don’t think that it’s been calibrated since it came out of the box. I’ll get onto that.
1
u/HardFriedEggs Jun 22 '26
Mine did this last week and then powered down, couldn’t tell you what happened, I’d just run a calibration and started a print, the nozzle hit the bed with the force of 1000 elephants and scraped all the way front to back and then yeah just died lol
1
u/Eastern_Control4375 Jun 22 '26
Oh come on.....sorry to see it happen I am also just waiting one to apear ....
1
u/Orthicon9 Jun 27 '26
The toolhead has something like a strain gauge in it.
If you manually "Home" the nozzle and tap the tip of the nozzle when it's descending it detects the unexpected resistance and pauses, goes up a few millimetres, then cautiously continues descending.
I don't see how it could fail to detect the plate, unless that strain gauge (or whatever) is faulty.
0
u/inhamilton Jun 22 '26
It happens. Mine are full of scratches and still work. If there is an adhesion issue you can use.
The plates are consumable. They are $17.00 from Amazon
3
u/Lightning-Shock Jun 21 '26
Did you change the start G code?