Underextrusion?

Bambu Lab A Series Troubleshooting
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I’ve been printing just fine for the longest time. Then suddenly, I’m having print problems. Its around the time I got the printer update 1.07.00.00 that I started underextruding.
I’m trying to print with PLA here. 220C for nozzle temperature. I’ve tried 2 hotends. Both used. So I have a new one ordered. Aside from a clogged nozzle (new hotend should fix that) what else could it be? I’ve tried printing at 250C and same result.
When it’s running, it seems to make this scrapping sound. But I do a bed leveling everytime I print.
I’m able to purge just fine though.

Thoughts on this?

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I have the exact same issue on my A1. Tried 3 hot ends, ran calibrations, changed to different PLA brand. Nothing seems to work.

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Nozzle clogged, filament cannot be fed cleanly, extruder gears have a problem with feeding, incorrect value for flow ratio in the filament settings, significant deviations in the filament with regard to the 1.75 mm, … Underextrusion can really be caused by many things …

4

Have you tried reverting to the previous version of firmware on the printer?

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I would do flow calibration as well as checking the extruder gears. And replace nozzle if you havent tried that first.

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I did not know you can revert back to the old FW. I did a factory reset and the problem remains.

How do I revert to the previous FW?

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Sooo…how’d you fix your issue?

8

the printer can extrude fine. So when I do a filament change and it purges, it works just fine.
Still think it’s the bad extruder?

9

Flow rate calibration? I wasn’t able to do it since it required me to print several squares out. I can change filaments just fine. So the extruder is fine, right?

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It could be an extruder issue. Have you taken it apart to inspect/clean it? Flow rate calibration is also a possibility. I would eliminate the ‘mechanical’ and ‘software’ variables before doing a calibration or you are calibrating to a abnormal condition.

You can revert to previous firmware using the Handy app.

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I’m trying to fight this underextrusion problem

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I found some posts about adjusting the Z-offset. I find that my z-offset for my plate is -0.02 already. What is the typical z-offset for the textured plate?

I think default is -0.02. I don’t have much room to move up anymore.
The hot end is poked around the plate before printing. Shouldn’t the bed leveling take care of this?

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What layer height are you trying to print for the initial layer? Are you sure you have the textured plate selected when slicing?

Have you tried cold pulls?

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I bet it’s the extruder. It can extrude but can’t keep up with the flow, either the extruder wheel is worn or the yellow gear is slipping around the shaft (or the extruder motor but less likely). That is if you checked it and did not find obstruction which could explain.

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The A1 has a known issue in that the print head screws can rarely become slightly loose. Check/Retighten the print head screws.

Other, more common, root causes are nozzle clogs or issues with the extruder.

I’d advise against fiddling around with the z-offset at this stage. Similarly, 1st layer height should not be lowered too much. It is less risky to check flow by increasing 1st layer line width (after cleaning the nozzle and maybe the extruder).

Hope this helps and :four_leaf_clover: & :crossed_fingers:

15

Ding Ding! The problem was a worn extruder! I replaced it, and it all came back together. Thanks to those who offered suggestions.