A1 Mini: 70h+ troubleshooting, still no root cause identified

[Warpheus]

# A1 Mini (<1 month old) | 70+ hours troubleshooting, 50+ test prints, repeated failures, seeking technical feedback and warranty review

## TL;DR

My A1 Mini is less than one month old and has exhibited quality and reliability issues since day one.

After:

- More than 70 hours of troubleshooting

- More than 50 test prints

- Multiple calibration procedures

- Multiple support configurations

- Multiple slicer profiles

- Multiple temperature tests

- Testing with both 0.2 mm and 0.4 mm nozzles

- Testing with Bambu PLA Basic and PLA Matte

- Extensive comparison printing on several different printers

the issues remain unresolved.

The most concerning observation is that identical models, settings and filament were successfully printed on:

- Another Bambu A1

- Ender 3

- Prusa Mini+

- Neptune 4

while my A1 Mini continues to exhibit repeated support failures, poor underside quality, overhang issues and inconsistent print behavior.

I am not claiming to know the root cause.

I am looking for honest technical feedback from experienced users and trying to determine whether the observed behavior is normal, whether a hardware issue should be considered, and whether a warranty review would be reasonable at this stage.

-–

## Background

Hello everyone,

I am creating this thread as a central reference point for an ongoing issue with my A1 Mini.

The printer is less than one month old and has exhibited problems since it was new.

A support ticket with Bambu Lab is currently active and contains the complete documentation, including photos, videos, project files, troubleshooting history and support communication.

Over the last several days I have worked extensively with both Bambu Support and community members in an attempt to identify the root cause.

Unfortunately, despite a very large amount of troubleshooting, testing and documentation, the issue remains unresolved.

At this point I am seeking additional technical opinions and would also like to document the case in a single location for anyone interested in reviewing it.

-–

## Previous Community Discussions

Bambu Forum - Arch Tip Failure Discussion

Arch tip repeatedly fails despite heavy Tree Strong supports (terrain model)

Hi everyone, I’m trying to reprint only the upper arch section of a terrain piece on an A1 Mini and I’m running out of ideas. Printer: - Bambu Lab A1 Mini - 0.4 mm nozzle - Matte PLA - Textured PEI plate Background: The original model mostly printed successfully, but the upper arch section failed. Instead of reprinting the entire piece, I cut out only the arch and am trying to print it separately and glue it back onto the finished model. What confuses me is that the failure keeps happen…

Bambu Forum - Resin2FDM Discussion

https://forum.bambulab.com/t/re-resin2fdm-a1-mini-0-2-nozzle-looking-for-feedback-quality-settings/257736

Reddit Discussion

https://www.reddit.com/r/FDMminiatures/comments/1vbv372/a1_mini_02mm_nozzle_support_issues_either_they/

These discussions contain additional photographs, project files, test results, support analyses and community feedback.

Several experienced users have reviewed parts of the evidence and offered troubleshooting suggestions, profile reviews and alternative theories.

While opinions differ regarding the root cause, several users have commented that the observed failure rate and print-quality issues appear unusual compared to what they would normally expect from an A1 Mini.

-–

## Main Issues

### Print Quality

Repeatedly observed:

- Poor downward-facing surface quality

- Poor underside quality

- Overhang sagging

- Bridging defects

- Rough supported surfaces

- Significant degradation of overhang and underside quality at higher-detail settings

- Increased problems when moving from 0.20 mm to 0.08 mm layer heights

### Reliability

Repeatedly observed:

- Supports breaking mid-print

- Supports failing near the top of the structure

- Supports detaching while still attached to the model

- Partial print failures

- Complete print failures

- Failures occurring after several hours of otherwise normal printing

- Similar failures across multiple unrelated models

### Additional Mechanical Concerns

Observed independently of the print profile issues:

- Visible dent/imperfection in the heated bed

- Filament cutter lever not reliably returning to its resting position

- Clicking/clacking noises from the Z-axis

- Possible irregularity on the Y-axis assembly

-–

## Troubleshooting Already Performed

I have already completed:

- Factory reset

- Full printer calibration

- Manual bed tramming

- Flow Rate Calibration

- Flow Dynamics Calibration

- Hotend inspection

- Tightening of hotend assembly screws

- Multiple support configurations

- Multiple slicer profiles

- Significant speed reductions

- Temperature towers

- Extensive temperature testing

- Multiple miniature models

- Multiple support-heavy models

- Multiple calibration models

- Testing with 0.2 mm nozzle

- Testing with 0.4 mm nozzle

- Testing with Bambu PLA Basic

- Testing with Bambu PLA Matte

Environment:

- Filament dried daily for approximately 6 hours at 55°C

- Printing directly from the dryer

- Room temperature between 22°C and 24°C

- Relative humidity between 40% and 55%

-–

## Comparison Printing

One of the strongest reasons for my concern is the comparison testing.

The same filament, project files, support settings, orientations and models were tested on:

- Another Bambu A1

- Ender 3

- Prusa Mini+

- Neptune 4

The comparison printers completed prints that failed on my A1 Mini.

The comparison printers also produced:

- Cleaner undersides

- Better downward-facing surfaces

- More reliable supports

- Significantly fewer failures

Even the Ender 3 produced cleaner undersides than my A1 Mini.

This makes it difficult for me to conclude that the issue is solely caused by the model, filament or slicer settings.

-–

## Concerns Regarding the Support Process

I want to be careful here because I understand that support teams often follow established troubleshooting procedures.

However, after more than 70 hours of troubleshooting and more than 50 test prints, I am becoming increasingly concerned about the effectiveness of the current process.

Response times are frequently around 24-48 hours.

In many of my replies I provide:

- Detailed written observations

- Photos

- Videos

- Project files

- Comparison-print results

- Additional testing beyond what was requested

However, it often feels as though the majority of this information is not being addressed directly in subsequent responses.

Instead, I am frequently asked to perform another isolated troubleshooting step despite already having completed extensive testing.

Examples include:

- Repeating calibration-related procedures

- Repeating standardized test prints

- Reprinting a standardized model with glue despite extensive previous testing and proper plate cleaning

- Increasing PLA print temperatures to 230-235°C despite the fact that I had already performed temperature towers and testing throughout the recommended PLA temperature range

I am not opposed to additional testing.

What I struggle to understand is what specific hypothesis is being tested and how these requests relate to the larger pattern of symptoms that has already been documented.

At this stage the case includes:

- More than 70 hours of troubleshooting

- More than 50 test prints

- Multiple nozzle sizes

- Multiple filament types

- Multiple support strategies

- Multiple slicer profiles

- Temperature testing

- Comparison testing on several other printers

- Mechanical observations unrelated to print profiles

Because of this, I am increasingly concerned that the case may be approaching the limits of what can reasonably be solved through incremental first-level troubleshooting alone.

My intention is not to criticize individual support agents.

Rather, I am concerned that the overall pattern of issues may not currently be receiving the broader technical review it requires.

-–

## Why I Am Concerned

I am not claiming that the printer is definitely defective.

I am also not claiming to know the root cause.

However, after:

- More than 70 hours of troubleshooting

- More than 50 test prints

- Extensive documentation

- Community review

- Comparison printing on several other printers

- Multiple unresolved mechanical observations

I am increasingly concerned that there may be an underlying hardware, assembly, alignment or manufacturing issue affecting this particular unit.

The combination of repeated support failures, inconsistent behavior, poor underside quality, positional quality differences, unusual mechanical observations and comparison-print results makes it difficult for me to attribute everything solely to slicer settings or normal print variability.

-–

## Questions

I would greatly appreciate feedback from experienced A1 Mini owners and experienced FDM users.

In particular:

- Do these results appear normal for an A1 Mini?

- Have you experienced similar behaviour?

- Could the combination of symptoms indicate a hardware-related issue?

- Is there any diagnostic path that has not yet been explored?

- At what point would you personally consider a warranty review, repair or replacement reasonable?

Thank you to everyone who is willing to review the case and provide feedback.

[CarbonForge]

Nothing from your initial thread even remotely qualifies as warrantable at this point IMO. Failures are always possible in 3D printing, and more complex prints correlate to higher chances of failure.

You would need to print some standardized test prints using default settings, and have those come out very abnormally bad to be able to point to a machine defect; I haven’t seen that anywhere.

The fact that your issues were corrected through slicer settings makes it pretty clear that the printer doesn’t have an issue. This was a very complex print, you succeeded with help.

Yes, other printers could print this - but unless you’re doing an apples to apples comparison (the other A1 is the only valid data point) where the printers are in the same space, using the same filament, printing the exact same sliced file, you can’t draw any conclusions at all.

It could literally be down to your printer being in a location that’s a bit drafty sometimes.

Bambu owes you a working printer, which they appear to have provided. Bambu doesn’t owe you success.

[Warpheus]

Thanks for the feedback.

I agree that a single failed miniature would not justify a warranty claim.

My concern is the overall pattern observed across 70+ hours of troubleshooting and 50+ test prints, not any single model.

So far I have tested:

- Multiple models

- Multiple support strategies

- 0.2 mm and 0.4 mm nozzles

- Bambu PLA Basic and Matte

- Multiple slicer profiles

- Temperature towers

- Flow Rate and Flow Dynamics calibration

- Factory resets

- Full recalibrations

- Manual bed tramming

In addition to the print-quality issues, the printer has also shown several mechanical concerns since it was new, including:

- Filament cutter lever not returning correctly

- Dent/imperfection in the heated bed

- Z-axis clicking/clacking noises

- Possible irregularity on the Y-axis assembly

I also had issues with the test prints provided by Bambu Support. One standardized Bambu test print was knocked off the build plate during printing, while other test prints continued to show the same pattern of degraded overhangs, downward-facing surfaces and quality changes at certain print heights.

I agree that comparisons with another A1 are the most valuable. However, the comparison printers were used mainly to verify whether the models themselves were printable. The same models completed successfully on another A1 while continuing to fail on my machine.

I would also respectfully disagree that the issue was resolved through slicer settings. Some individual prints improved, but the overall pattern of support failures, poor undersides, overhang issues and inconsistent behaviour remains.

As another example, I have attached photos of a recent Benchy. This is not a miniature and does not rely on complex support structures, yet there are still noticeable issues around the cabin roof, roof edges, door opening and overhang-related features.

What concerns me further is that reducing layer height does not improve the results. Quite the opposite. When moving from standard settings to 0.08 mm layers, and especially when using the 0.2 mm nozzle, the same issues become dramatically more pronounced. If this were simply a difficult model or support profile, I would normally expect higher-detail settings to improve quality, not amplify the problem.

I am not claiming the printer is definitely defective.

I am simply trying to determine whether the totality of the evidence is still consistent with normal printer variability or whether a machine-specific issue should remain under consideration.

[CarbonForge]

@Warpheus

• Filament cutter lever not returning correctly

• Dent/imperfection in the heated bed

• Z-axis clicking/clacking noises

• Possible irregularity on the Y-axis assembly

Ok, so where are your threads asking for help resolving all those items? Or asking if they’re even issues?

It looks to me like you’re not making a good faith effort to address each issue, but rather you’re trying to build a list of perceived problems to make the case that you’ve got a lemon. That’s not how this works. Don’t be like that.

[CincinnatiDesigns]

Repeating what was already written doesnt help.

Go ahead and put the 0.4 nozzle back in and print a benchy from the built in files on the SD card. It is best to judge the print quality on a base line.

[Warpheus]

I think that is a somewhat unfair characterization of what I have been doing.

I did not start with the assumption that I had a defective printer.

In fact, that is precisely why I have spent more than 70 hours troubleshooting instead of immediately requesting a replacement.

The print-quality issues were the reason I opened the support ticket.

The additional observations came up during the troubleshooting process and were reported to both the community and Bambu Support as they were discovered.

For example:

- The heated-bed dent was submitted to Bambu Support for evaluation and I specifically asked whether it was within tolerance.

- The filament cutter issue was documented and reported.

- The Z-axis noise was documented and reported with video.

- The possible Y-axis irregularity was compared against other A1 Mini units and raised as a question, not presented as proof of a defect.

At no point did I claim that any of these observations individually prove a faulty printer.

My concern is simply that multiple unrelated observations have accumulated alongside persistent print-quality and reliability issues, despite extensive troubleshooting.

If the printer were consistently producing expected results, I likely would not have paid much attention to any of them.

I am not trying to build a case for a lemon.

I am trying to understand whether the totality of the evidence is more consistent with normal printer variability or with a machine-specific issue that has not yet been identified.

[Warpheus]

I did that and i provided the pics in this thread…

[CincinnatiDesigns]

1. Check if your cooling fan is working
2. Check the screws for the hotend heating assembly
3. Do a few cold pulls
4. Run a full calibration

In that order, then run another benchy.

Are you trying to modify anything like the filament profile?

To me it looks like you are either running too hot or without sufficient cooling.

[CarbonForge]

@Warpheus

For example:

• The heated-bed dent was submitted to Bambu Support for evaluation and I specifically asked whether it was within tolerance.

• The filament cutter issue was documented and reported.

• The Z-axis noise was documented and reported with video.

• The possible Y-axis irregularity was compared against other A1 Mini units and raised as a question, not presented as proof of a defect.

We’re not Bambu Support. You’ve mentioned these issues in passing without providing any actual details, and then you’re asking us to tell you if this constitutes a bad machine. This is rubbish, you are absolutely trying to build a case that you have a bad machine.

[NicPlays3D]

Thank you @CincinnatiDesigns . Sincerely appreciate you taking the time to guide the OP. I like this place more and more.

[Neiljt]

It appears the benchy above is missing a hull line or speed change associated with benchys

[CincinnatiDesigns]

Should be pretty easy to figure it out. The A1 mini is not a very complicated printer.

Trying not to be negative, but it looks like they might be causing secondary effects when trying to solve the original issue.

Preferably I would like to see what caused them to start troubleshooting in the first place.

[MZip]

@Neiljt

It appears the benchy above is missing a hull line or speed change associated with benchys

It looks like it’s there to me. I even checked to make sure it’s what’s in the photos above.

[Warpheus]

The fan is running at 100% per profile. I verified it, but i cant say if what I see really is 100% because I only have this one A1 mini.

Hotenend-Assembly screws were checked on Thursday or Friday (following the wiki, the 4 screws behind the 3 screws were you could destroy the wiring.)

Cold pulls are done several times also on Thurdsay or Friday

Full calibration was also done, including factory reset and manual bed trimmins.

These steps were all ordered by support and I followed them meticulously.

I also did several temp-towers after the full reset to find the ideal temp which is around 215°C. I tested some short prints between the allowed spectrum but I couldn’t find a conclusive difference.

[MZip]

@Warpheus

I also did several temp-towers after the full reset to find the ideal temp which is around 215°C.

You might want to post good photos of any calibration models you print. It can help others troubleshoot.

[Warpheus]

I started troubleshooting, because the print quality of downward facing areas were really bad AND I couldnt finish a single print including supports with normal settings. I could finish supports, but then I wasnt able to remove them, because the melted to the hull of the print.

[CincinnatiDesigns]

For the sake of sanity, just try those steps again.

I would even add cleaning the extruder gears.

Attach the settings as a 3mf for the most recent print that you have done.

[Neiljt]

Nah this what a hull line is

[Warpheus]

Ok, I will try to muster enough energy to go through all of it again. The printer is not even 30 days old

[MZip]

@Neiljt

Nah this what a hull line is

No. Not “nah”. They are both what hull lines are.