Glass print bed Home Z Axis error

Bambu Lab X1 Series
1

I have a question for those who use a glass plate or similar on their printer to compensate for the crooked bed.

I have now with the glass bed more and more the problem that the prints are aborted shortly after the start, because the Error Home Z arises when the printer runs Home after the first purge in the back center. In 4 out of 5 cases, the error occurs and the print aborts.

When the printer executes Home in the middle of the print bed, everything works without further problems and is executed successfully. Only when it tries to home at the beginning of the print after the purge at the back, the error occurs.

Does anyone have any idea what could be causing this all of a sudden?

1 Like
2

I mentioned and resolved this issue in Warped bed :( seems like a common QC issue
The problem is in too much stress on one of load sensors because of increased weight of the heatbed. The solution is release bed tensioning screws by half the turn and do the tramming procedure. Repeat if the problem persists. Total 1.5 turns did the job for me.

3

I am pretty sure that someone had explained that when you do any mods to the bed, you need to run the bed tramming.

4

Bed tramming was of course performed several times according to Bambulab instructions, but unfortunately did not bring any change.

5

So you mean loosen the screws a bit and THEN do the bed tramming again?

This could possibly be a solution, I always do it as Bambulab specifies and bring FIRST all screws to the same level and then do the bed tramming.

6

Yes, exactly. If you start with the screws flush as the manual says, there is too much tension on the sensors.

7

Fun fact: when I got my X1C, the screws were loosen by more than 2 turns from factory. When I followed the tramming procedure exactly step by step, I started to get Z homing errors even without the glass. So, making the screws flush in the beginning is maybe good starting point, but it should not be strict rule.

8

I tried your suggestion, and now I get the error that sensor 2 is too sensitive…

Seems to be quite sensitive, these pressure sensors.

So we try the whole thing now again with a little less turns on the screw.

9

So I have now spent a good 3 hours testing every possible variant… From too tight to too loose… It is simply not possible to print properly with the glass plate.

Either the home z error occurs after the print start or it aborts before because of sensor error.

I do not know for the life of me how to proceed to print with a glass plate.

10

This is quite strange. If you did everything right, then the only explanation (for me) is that one of the sensors has very narrow operating range of tensions. Maybe it could be reason for having it replaced?
Try to talk to support.

11

Hi, that’s kind of what I was thinking and have already contacted the support team, thanks for your tips.

12

Do you have an idea what the printer means when telling me “Sensor 2 is too sensitive”?

13

Does it say any error code?

14

This time I took a picture of the message, since it can’t be tracked in the app, and it says the following:

Heatbed force Sensor 2 is too sensitive. It may be stuck between the strain arm and heatbed support, or the adjustingscrew is too tight. [0300 0b00 0001 0001 0701 26]

The thing is that this error only occurs when I have the screws quite loose…
Everything I find about this in the wiki doesn’t really match the actual error.

15

And this is with glass on top of the heatbed, right?
I wonder, how did you fix the glass to the heatbed?

16

Yes, that is correct, with the glass bed, without it there are no problems. Except that my print bed is as crooked as a banana.

I just temporarily secured the glass bed with tape. I also have some clips to secure it, but I didn’t want to use them for now because of the potential space that would be lost, and the additional obstructions caused by the clips. I also assumed that the clips would put too much pressure on the underlying print bed and sensors.

Could it be the tape is too tight or too loose? I thought of that too and tried it with different tightness. No difference detectable.

17

I’m sorry but I’m running out of ideas. It seems to me that particular sensor’s range of working parameters got reduced or maybe the heatbed isn’t assembled correctly, something like that.
If you’re brave enough, you could try to disassemble and assemble the heatbed just to check if there is anything wrong, but it’s tricky task, because if you mess anything up, you’ll end with unusable printer.
Maybe first open a ticket, complain about warped bed, ask for a replacement, wait for it and only after it is delivered, do further investigation, if it’s still an issue. It’s easier to dig into something when you have spare part ready.

18

Do you, by any chance, have this mounted on your heatbed to help you align the plates ?
https://www.printables.com/model/425663-bambu-lab-build-plate-alignment-brackets-extension/files

I’m asking, because I was scratching my head having the same error as you and even a completely loose screw would throw errors. And I then I realized there’s this thing clamping hard on the plate and sure enough, removing it caused the error to go away.

19

Hey, actually I installed this part in the meantime, but only because I didn’t find a solution and funnily enough it seems to work since then plus I tightened the level screws as tight as I could… So far it seems to work.

Actually, this guide should not exert any pressure either, since these guides are actually only attached to the outside of the actual guide.

Bottom line is that we are just as smart as before as it is completely confusing as to what is causing the problem or what the actual solution is.

20

Really puzzling indeed.
Did you notice any “too sensitive” or “homing abnormal/failed” errors ever since?