So I had a scarry moment. I got an error that the bed leveling failed due to failure to zero, i.e. home the Z-axis. Error was mentioning possible ‘foreign object’. I checked around the torsion spindle bars and underneath the printer first. Nothing but small debris. By closer inspection I noticed a ‘spiral of poop’ had made its way into the cavity around the rear torsion spindle, hiding out of sight and preventing the bed to move all the way up. This, by further inspection, seems to be caused by, should I say a ‘peculiarity’ with the way the hot bed retracts/‘homes’ before a new print starts. Or should I say not completely homes. The bed seems to stop an inch short leaving a gap between the top of the bed and the rear spindle large enough for the ‘priming extrusion’ to get in there. In my opinion the priming process should not start until the bed is fully up, closing the cavity more enough. I noticed that the nozzle priming process starts while the bed is homing. If the priming extrusion does not get expelled into the shoot, but for some reason (viscous filament?) reamins attached to the nozzle and getting dragged over onto the bed, it can happen to end up in the cavity next to the rear spindle. I guess I was the lucky one using Bambu Lab Tough PLA.
What is the solution? One, check in the back before every print. Or just wait until the error (rarely?) occurs? And then check back there. Or change the g-code to make the extrusion priming start after the bed has completely homed itself?
I am not sure how and why the ‘vigorous’ wiping mechanism/process did not detach the poop from the nozzle in the first place. It should have and should have sent it down the poop-shoot.
Anyway, glad that nothing got damaged or out of alignment. I hope.
I had the same problem on my X1 Carbon when I wanted to print any filament other than PLA and with a plate other than the cool plate. The error was Homing Z axis failed [0300 4000]. I found the solution on the Bambulab Wiki. In fact, you have to slightly advance the heated bed so that it does not touch the excess drop receptacle.
Here is the link of the wiki page procedure : https://wiki.bambulab.com/en/x1/troubleshooting/homing-z-axis-failed_part-unit-interference
Thanks for the info. I don’t have the problem with a misaligned heat bed, but it was an ‘excrement’ that should have gone ‘down the chute’. Instead it ended up near the rear bearing on the bed carriage. How it remained there during the bed movement and didn’t fall down in the space behind is unclear. But what the further concern is that I observed several ‘spirals’ of excess filament ‘dangling’ from the nozzle and being carried over when the nozzle is being wiped on the wipe tab. That’s where it comes off and may end up in that opening behind it where the drive screw is located. It will cause problems during bed levelling, but if it somehow is not quite all the way in the opening it might not. But it might, as in my case, end up in there during the print process when the bed moves down and then later during homing for a new print it will.
So that was a long-winded description. But the lesson for me is to now be close when a new print starts and check the space back there frequently. And of course remove any excess dangling from the nozzle.
At any rate I still wonder why the excess from filament purging does not get removed by the mechanism in the chute. It’s usually very noisy and active, but doesn’t seem to do its job that well anymore.
Thank you for your feedback. I hope you can resolve this problem, otherwise do not hesitate to contact Bambulab support who will surely find a solution to this problem. Have a good day and above all happy Christmas holidays.
Thank you and Happy Holidays as well.
So here is my follow-up question:
Why is the heatbed not homing completelywhen I start a new print?
Every printer I previously owned homes all the axis before a new print starts. On the X1C, when the bed is at or near the bottom it only halfway homes the bed, Then the hotend goes to the chute and loads the filament and ‘poops’ out the excess with wipe movement to clean the nozzle. Only then, later , the bed is move to the home position.
Is there a reason for this? Is my gcode corrupted or does every X1C, P1P, P1S do this?
I before blamed this behaviour on the problem I had with an extrusion lump ending up near the rear leadscr on the heatbead and then preventing a homing completion. This could be prevented if the heatbed homes completely before the filament is loaded and the rear lead screw opening is just a slit so that no excess lump can get in there.
Anyone, enlighten me. Is this a quirk that needs to be fixed or is it intended by BL?
I had this very same thing happen once, and it happened with in like the first 10 prints done on the printer. While I have had other poop not make it down the chute. It was the only time it got stuck just right on the rod to goof the print. It don’t seem to be a common issue, but very rare one. I do find if you every now and then heat up the tool and wipe the tip clean with a paper towel helps. Majority of it goes down the chute though (99%+) and it’s a very rare occurrence for it to mess with the homing in my case. If you find it happening often, I would contact support.
As long as the printer is on it remembers where the bed is. Also, X1c uses LIDAR and camera to see where things are. It is working as intended. Mine does the same thing with the bed just keeps it out of the way until it’s time to measure the tool. Quite amazing how it works you can even loose power and the printer will pick up where it left off. Although bed temp can mess with adhesion at that point if its too long.
Since the latest firmware update I’ve had my P1S lose it’s homing (now multiple times). For me it happens on taller objects. It seems when the bed moves down low enough to remove the print, it loses its home. Of course I’ve got suggestions, NONE of which were applicable, and it NEVER used to do this until the recent update. Something the suggestions seem to ignore.
I’ve taken to homing it myself before starting any print if the bed is past halfway down, just to bypass the issue. So far, have had no more issues as long as I do this.
And no
- Obstructions are not the issue
- Plate installation is not an issue (I’ve let it cool completely, romved the print w/o taking the plate off. Verified it was mounted correctly and it STILL happened)
- I posted before, the heights I printed when this happened. Which were consistently above the height I listed, and repetition usually indicates a repeatable issue. So it’s not related to an individual file (Totally ignored by the replies I got)
So I’m looking at a firmware bug as the exact same unmodified file printed before the firmware update did not show this issue. Would be nice if BL would look into this.
Not in my case listed above. Printer was NOT turned off. But there are differences in the X1 firmware and P1 firmware, which may be why you don’t see this.
OP is talking about an X1 not a P1. Printers are very similar but quite different in many ways. Why, they even have their own separate forums to discuss issues etc. On the issue you’re having I would try a factory reset something after the update might be confused with a setting in the machine.
It should be a command in the gcode that is issued everytime a print is initiated. The code should first home everything and then load the filament and purge excess. Unless the firmware does its own thing and manages the bed return, lidar, hotend by itself in a different order when the print command arrives.
I am doing the same thing as you now, I home the bed manually and check for debris before every print.
I now took a closer look at what is happening when a print is initiated with the X1C. I noticed that even when I manually home the bed, just before the filament is loaded, the bed is dropped by about 1 1/2 inch and then the priming/extrusion process starts. So the rear cutout is ‘open’ anyway. Does BL keep the bed away from the 250 deg hotend during the priming process on purpose? But with higher temp filament types temperatures can also reach 250 deg during printing. So what is going on?
This is most like my problem, After the update… it got an OTA after doing a print and i kept printing. The last print was a failure got a y shift on my part and spaghetti’d from there. printed several before and was going to do more, but now it goes home and above. Crashes the tool head, applies upward force and you can see the carbon rods being bumped also. Not cool. Factory reset, updated again, same results. Vacuumed everywhere i could with a car vacuum, smaller hose to get everywhere and still the same. Machine is clean and was printing fine before the update, Now its a door stopper. I’ll call for support when i can get away from Job doing OT all the time.
The EXACT same thing just happened to me. never saw it but after homing it several times it shook itself from around the corner and I removed it. never would have guessed!
Hmm, you repeated what I already said about mine being a P1 and not an X1. And I had already done the factory reset with no change. Issue disappeared on a later update, so it WAS a firmware bug like I thought.