Print head not going back far enough, can't wipe, calibrate, or cut

Bambu Lab H2 Series Troubleshooting
1

The last day or two has been a series of errors with my H2D and I’m not really sure what to do; I’ve had a bent nozzle blocker, stuck purge wiper, offset calibration errors, and cutter issues.

I’m a relative newbie to 3D printing as I bought this only around a month and a half ago.

Thursday
Nozzle blocker caught on something and broke off; the remaining piece is all twisted (picture at end), I contacted support and replaced the blocker. Printed PLA/PETG fine all day.

Friday
Printed with left and right nozzles fine in PLA/PETG all day, then did two successful TPU prints in the evening. I manually unloaded the TPU and then loaded and manually flushed PLA.

Noticed that the purge wiper wasn’t working; it was always in the position for “closing” the purge chute (picture at end).

The printer could not print anything due to offset calibration errors (0300-4010 023003). At the same time, on Bambu Studio, I got a slightly different error: 0300-4010 033003.

I tried multiple times, checked that the sensor is clean and completely plugged in. At this point it was around 3 AM, so I gave up and went to bed.

Saturday (today)
Woke up, rebooted the printer, tried the high precision calibration (Bambu black PLA in left nozzle, white PLA in right nozzle, both from Bambu) and now the right extruder is raising a “failed to cut the filament” error (07FF-8001 095103).

The cutter works normally manually.

Does anyone have any suggestions? I’m feeling like all three of these issues could be related.

Twisted nozzle blocker

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Purge wiper stuck in “closed” position

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Edit: had to edit and reupload the pictures because they weren’t displaying.

2

I just noticed that when it tries to wipe, it doesn’t go back deep enough as well, which could explain the purge wiper issue. So something is keeping it from going back far enough, which is also why the cutter isn’t engaging with the side bar to push the cutter lever.

Any ideas on why it’s not going back far enough and how to solve this when I can’t calibrate?

3

I went around and checked all of the belts etc. for anything out of the ordinary, couldn’t find anything.Tried a nozzle offset calibration and it failed because the nozzles won’t go back far enough.

I manually sent the head back as far as possible and took some pictures; you can see here that it’s not going back far enough to engage the nozzle wiper.

I took a wider picture as well so you can see the state of the belt and the little levers on the sides, if that helps.

I’d hoped to spend the end of my winter vacation printing up some stuff before I go back to work, but I guess that’s not happening! :sweat_smile:

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4

The stuck purge wiper seems to be caused by all the poop that is dropped in front of it.
Cleaning that out might get it back to work, but you can check that by manually operating the wiper with the orange levers at the rear.

All your trouble seems to be related to one initial issue.

Just open up a support ticket at BambuLabs. I wouldn’t try printing anymore because it feels like even homing might just make everything worse.

5

There isn’t any poop in front of it. It’s not stuck in that sense; it’s just not smooth if I manually push the lever in the back.

Already did on Thursday, just sitting around waiting for a response at this point.

6

Your first image seemed to show some poop in that area. But I think there is more at hand than only a poor nozzle wiper.
You can remove the nozzle wiper for closer inspection. It is a spare part that can de replaced as a unit.

That’s good, usually takes a couple of days before you get a response. Adding as much information as possible to the initial ticket will help in speeding up the follow up.

7

The issue isn’t the nozzle wiper, but that the head is physically not going back far enough. This is the root cause of those two problems plus the calibration issue.

8

By the way – I just realized what you meant, sorry!

That picture does have poop in front of the wiper, but that’s because I took the picture to illustrate how mis-aligned the print head is. It’s trying to extrude poop and is completely missing the target.

9

When you home the tool, does it actually tap the rear and right sides of the printer? Or does it stop before that point? Because of the way sensorless homing works, if there anything causing the motors to work hard (like something stuck to the rail or manufacturing defects), it will think its at the end of the home positions.

Edit: ding ding ding.

10

It seems to tap the sides, and it engages the lever on the left when going back. I took a video, but can’t upload videos here.

One other piece of “evidence” I have is that when it tries to calibrate and tries to get to the calibration sensor, these blue dots show where the right nozzle is actually going: pretty far off.

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Uploaded it to streamable, it’ll only be available for 48 hours: Watch IMG_1624 | Streamable

Sorry in advance about the background noise (air purifier) – you might want to play muted.

12

It definitely not going as far back as it should during homing. I would do a factory reset and re-try, something is wrong in this sequence. The drawback is you will have to start from scratch, select the region, bind your account, make a full calibration again…

13

Already ahead of you… tried powering down and unplugging it for 15 minutes in hopes that it would flush some temporary memory or cache, no joy – then I tried a full factory reset and it failed in the initial calibration due to this issue.

I also had the foresight to upload the logs to the support ticket before I did the factory reset, luckily…

14

can you push the head all the way to the back manually when the printer is off and the motors are not engaged?

1 Like
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Today I learned you can do this!

This is as far back as I can manually push the head. It lines up with the back of this blocker assembly (not sure about the actual name) though there’s still a bit of rod left behind that.

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There is definitely something blocking the Y-axis. Can you determine if the blocking is on the left or right side?
Or possibly somewhere else in between?

There must be a physical barrier causing this.

17

Both sides look clear, and I’ve felt around everything multiple times. I’m really at a loss here.

18

Pushing gently on the left or right side of the gantry, should feel a bit flexible or rigid. The rigid side indicates that this side is possibly the blocking side.
If both sides feel similar, it might be in the middle area.

Can you slide it left and right freely in the back? Be careful not passing over the nozzle wiper when moving left and right.

19

Sadly, all three feel equally rigid. I spent a while feeling around the whole gantry, belt, print head, and the side blocker/triggers, and I can’t feel anything physically blocking the gantry or print head.

It slides freely but less quickly than if I pull the gantry out toward me.

It doesn’t have a chance of hitting the wiper because it’s too high and also too far forward.

Here’s a variety of pictures I took in case anyone notices something unusual:

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20

Here are some things I noticed that I’m not sure about. This is tough to describe, so I’ll use an old picture as a diagram.

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A and B are connected parts; C hitting B moves A and vice versa. This seems normal.

If I push the gantry at a slow pace, it is forced to stop so that C is at D, before it hits B.

If I push the gantry at a faster pace, C moves farther and hits B, triggering A. This is not a rebound; it physically goes and remains farther than if I move it slower.

B and A have positions farther back that C cannot reach right n ow.

I’ve tried manually setting A and B farther back on both sides, but that has no effect on C.That is, the source of the stoppage is not B.

I cannot find a physical blocker on either side around the housing below C, or on the rails.

The printer head is not contacting anything in the back – there’s about a finger’s width of space between it and the back wall in the pictured state.