I am getting what looks to be under extrusion on some layers. I do not think it is a clog, as It only appears to be happening with this color. Ran the same print in a different color and no issues. All my currently loaded filament is IIIDMAX. Any ideas what might cause the issue? Maybe inconsistent filament diameter?
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Did you tune your filament profile or use the defaults? Is this PLA? If so, regular or Matte? Are you feeding from an AMS? Do you have a link to the exact filament?
Thanks for the response! Yes I did tune using both calibration tests in Bambu studio. The filament is IIID Max PLA+. It is typically my go to filament. I have used blue in the past without any issues. The issue also popped up in another print where I had two of a similar model on the bed. I did one at a time and they came out perfect. Yes I am feeding from the AMS. Maybe I should try a different slow? Could be the first stage feeder shipping maybe?
Two items here. First, as with all things related to troubleshooting, the first commandment is: Thou shalt change only one variable at a time. In this case, I strongly recommend eliminating the AMS for the time being and performing all calibrations with direct feed. This will isolate the filament feed to just the spool and the print path. If you have let’s say a snag in the AMS, it could throw off your calibration.
On the subject of calibrating filament. If you relied on Bambu Studio, you might as well have just put random numbers into the filament profile.
The best utility for precision calibration is to use Orca Slicer which is a clone of Bambu Studio just more features. You don’t have to pick and choose, both slicers will coexist side by side on the same machine and can read and write the same 3MF files. Orca has calibration utilities baked in. Why is that important? Because many of the calibration models found on sites like Printables are just the STL. You have to know enough Gcode to manually go in and change the parameters such as in the Temp Tower where you have to tell the printer to change the extrusion temperature at each level of the model. Orca automates all of this.
Bambu Studio. Calibration tools are a waste of time.
Orca Slicer has a full suite of baked-in tools.
This guy at Butter Pocket Prints probably has some of the most straight-forward advice on how to use Orca to tune a filament. It’s not the only one on YouTube but it is a good starting point.
One word of caution: beware of irrelevant tutorials. There are many calibration videos on YouTube that discuss topics like Z-Axis tuning and other non-applicable subjects for a Bambu printer. These tutorials are largely geared towards printers that must be assembled by the user. They are kits, not a finished product like Bambu. Stick with tutorials specific to Bambu for now until you gain more experience. Otherwise, you’ll get sucked into a rabbit hole and start thinking you need to adjust belts and such, which is usually unnecessary and can often cause more harm unless you truly know what you’re doing.
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Be sure to dry the filament a few hours before printing.
I had similar problems with PLA from a supplier some time ago. Before I threw the filament away, I decided to dry it and, lo and behold, the printing results improved again. I then bought a Sunlu S4 dryer. The problem with wet filament is its unpredictability in terms of its extrusion. You can get the most inexplicable problems if the filament is not dry.
When the filament is dry, calibrate it after you have created a print profile for it, in which you first set the framework data (temperature range for printing, the temperatures for the build plates, extrusion rate mm³/s). Select this filament profile for the pressure calibrations. This means for the calibration of the K-factor and the filament flow (which is normally less than 1). Carry out the calibrations manually. Automatic calibration before printing works, but depending on the type of filament, it may produce accurate or sometimes even very inaccurate results that negatively affect the filament flow.
Good luck!
It could definitely be related to inconsistent filament diameter, especially if it’s specific to that color or batch. Sometimes even slight variations can cause underextrusion. Have you tried measuring the filament diameter in a few places to see if there’s any significant difference?
Thanks for the information, I have used those tools before, but never without the AMS. Had the issue manifest today with another filament. Same brand, different color. Filament is new out of the package and dried for 12 hours. Spool look good too, no warpage. Tried different AMS units as well with the same result. I’ll run through calibrations again using orca slicer and see what happens. Thank again.
Hi. Have you managed to solve this problem? I have the same thing on almost every model, regardless of the type and color of plastic. I don’t know what to do anymore.
Perhaps you should contact Bambulab Support? It is possible that the heating bed is not completely straight. It can be levelled. However, this is not entirely trivial and requires some effort.
I noticed that on small models like the XYZ test cube, this is not the case. But on larger models, these gaps appear somewhere. I print using AMS, and due to poor winding, printing often stops and I have to adjust the thread. Could it be related? None of the plastics were dried, I printed them immediately after taking them out of the box, but I don’t think that’s the point.
So you think it is the spool windings? The IID spools can sometimes be warped pretty bad. Maybe I’ll trying respooling onto a bambulab spool.
Just wanted to follow up that I solved the issue. The extruder gears were extremely worn. I replaced them and it is now printing better than it has in months. I want to add this is not a production printer running 24/7. I do use it a lot (4194 total print hours), but I am surprised the gears wore down this quickly. I have some cheaper printers running years without this kind of wear. Maybe it is due to the speed differences. Regardless, I am happy to be back up and running!
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It would be useful if you could tell us how many hours your printer has been running. Then others can use this as a guide. I have also wondered after how long it would be worth servicing the extruder. Do you have any pictures of the worn parts?
I just added photos to and hours to my post. Didn’t even know you can look those up! 
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