I have had an H2S for a few weeks and was quite satisfied so far. Printed a few things. I then had unsightly problems with the Z-seam in the corners. They were very clearly visible and unattractive. I subsequently tested around with the retract and so on, and tried to improve things. Now, however, I suddenly have a completely different problem. This morning I noticeably redid the belt tension and performed a large calibration. Nevertheless, the result looks like the picture. Does anyone have an idea?
That’s not a Z-seam or retraction issue — it’s a layer shift.
Most likely the stepper motors lost position due to either too much or too little belt tension, or some kind of mechanical obstruction.
Since you recently adjusted the belts, you can’t reset them to a factory level — instead, re-tension them following the official Bambu Lab Wiki procedure and then check that both axes move freely without resistance.
Also make sure the pulleys are properly secured on the motor shafts.
I don’t have an H2S myself, but I’ve read that the PTFE tube from the buffer to the print head can sometimes be too short. Move the print head to all its limits and make sure the tube isn’t restricting motion in any direction.
Once everything moves smoothly, run a full calibration again before reprinting.
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I did the following on the day of the report to fix the error: 1. disconnected the printer from the power and restarted it. 2. performed a factory reset. 3. performed a large calibration. 4. performed a movement calibration. After that, I was able to print perfectly in good quality again without any further mechanical changes. Since then I have done two 14-hour prints and everything went well. Yesterday the exact same error occurred again. The subsequent print was again totally bad with layer shift. Essentially, just as can be seen in the picture.
Since I was already unsure last time which of the measures had solved the problem, this time I only did the following: Disconnected the printer from the power and restarted it, and then immediately sent the same print that hadn’t worked before back to the printer. Lo and behold… everything was perfect again.
How can such an error occur? Do I now have to restart the printer every time and after every print? That surely can’t be necessary at this price point?!
During these bad prints, the print head also always runs through some patterns that are not in the G-code and there are rattling vibration noises and occasionally a bang. I believe the bang comes from a belt skip. However, as I mentioned, the belts have the correct tension, and after restarting the printer, everything runs perfectly again. What could this be?
Now I have the next Problem. The Extruder Gears do not overtake the filament from the feeder. I found this Video of the problem. So I am not alone.
https://www.reddit.com/r/BambuLab/comments/1nbnzsu/h2s_extruder_gears_does_not_grip_the_filament/
I also found a video of my other problem in this post. There seam to be other people having this trouble.
This is my problem!
My H2S has also issue with layer shift since yestarday and its getting worse.i have almost 1700h print time, last maintanance I did 2 weeks ago. Its worse along Y Axis than X. It doesnt seem to be affected by Z axis
I haven’t touched this machine being my HD2 in about a month. Today is July 22nd 2026. I had a lot of frustration with their ticket interaction with Bambu Lab. They suggested belt tensioning which was the very thing plus a handful of other things I tried and I presented that to them. They then suggested something else. I answered that I tried it without any positive results. Then they went back to the belt pensioning suggestion. I live in the United States in Pennsylvania and there are service places in Ohio and Virginia for this machine that are 3 hours away in one direction and you have to take your equipment they will not accept shiped units nor will they ship out which is understandable. Both facilities spend at least 30 to 40 minutes on the phone with me returning my call and we’re wonderful with ideas as they know there’s been problems with these machines. Before making such a trip they said try some of what they are suggesting. They suggested because my machine had been damaged, thank you FedEx for dropping off the package and running away when It was obvious that a forklift went through the side of it upon shipping. My unit now has 1047 hours on it and I have at least a tooth skip in the x direction. Their suggestion is to loosen the z guide rods one at a time and run my test walk and if it clears up reverse the order of tightening. They said it will settle itself down and they’ve seen this before. I feel more than likely I have a $2,500 paperweight and I won’t be buying anymore of their products.
The only recent successful print I had was the life-size macaws perch and the only way that happened was I did not allow the machine to dock by turning off the first layer inspection. This is where the problem seems to take place. Filament changes and docking there’s no obstruction there’s no belts rubbing or PTF tubes or the chain link. It appears that the drive gears on them stepper motors are fine. This is an aggravating piece of equipment. I’m going to give it away for pennies to put another U1 in its place and I won’t look at the Bambu again. Really a shame as I purchased five of their machines and I sent a total amount of six people to a sale of one of their pieces of equipment. I guess I’m still just a pimple on their butt and they have no time for me. And I’m sure they’ve read many of these posts I am so negative with them. I’ve contacted snap maker they sound like they speak tremendously good English or are American get back to you right away and they’re very gracious with help.
Snap maker U1 is a nice little machine. PETG and ABS have been printed on it because I did make an enclosure. Very frustrating that a lot of people are having the same problem I’m having and we can’t seem to find a solution and you would think the company would be very concerned as they’re going through a bunch of crap as it is and don’t need any more bad PR.
Anyway this post is a little bit of a vent and feeling for your situation and many others who are not getting any satisfaction. Really wish I never considered purchasing this machine.
What I don’t understand is why you didn’t immediately send the damaged printer back and get a new one sent out. Chosing to keep it and (somehow) put over 1000 hours on it was certainly a choice.