I have two X1C’s that I print almost exclusively with PA6-GF. One of them prints flawless parts, even on 24+ hour prints. The other one is starting to print what I will call “boogers” on the side walls of the parts and it getting progressively worse. I use Fiberon PA6-GF and use their recommended 40C bed temp and 300C nozzle temp on both printers. All prints are done with 100% infill. Both printers have the exact same nozzle, a 0.4mm Diamondback nozzle. I have almost Attached are some pictures I took this morning of a couple parts with these “boogers”. It is even printing “boogers” on the tree supports. Any idea what is causing this and how do I fix this?
Go back to your slicer for this job
Enable visualizer for travel
Do these pileups match a spot you see in the travels? Yes - Ooze, dry it again, or attempt to dial in retraction settings a little bit but IMO this is oozing.
Sorry, but where do I find “visualizer for travel” in bambu studio?
Yep thats it. There are 10+ visualizers in that dropdown to analyze, you’ve got the same breakdown [line type] but its hiding in there.
I would like to note another clue re: moisture/ooze/uncommanded extrusion:
Good find! How do I address and fix this? The filament is in box and rarely goes above 10% RH per the meter I can see inside the box. Is this a nozzle issue or a settings issue?
I can’t readily find Fiberon’s recommendations for drying, but Bambu’s flavor of PA6-GF calls for 85C 12h of drying. and is probably a good starting point.
Thanks for the information!
Let me ask you this…If “printer A” happily prints all day long with the exact same filament in the exact same environment (RH, temp, filament, etc) without any oozing or surface finish issues, but “printer B” in the exact same environment (RH, temp, filament, etc) oozes alot, isn’t it a printer issue, not a filament drying issue.
For example, yesterday I switched the filament from “printer A” to “printer B”. Then I switched the filament from “printer B” to “printer A”. I did this because I wanted to see if I had a bad spool of filament. However, “printer A” happily printed perfect parts from the filament that “printer B” had all sorts of oozing. Printer B had all kinds of oozing (the pics I provided in my original post) using the filament that “printer A” printed perfect parts. This leads me think it is a printer issue, not a filament issue. Is my thought process correct?
I would expect the problem to follow the filament. RH is a poor indicator for the moisture content of the filament, only for the environment the filament is in and how it might degrade/be preserved by being in that environment for periods of time. Active drying is how to get it out. You can measure the weight of the spool pre/post dry.
I don’t have much context for what else you’re seeing re: a/b. It’s plausible the extruders could be behaving differently. But given those travel lines you showed in the preview, it’s ooze related - your filament is supposed to be retracted and nothing coming out, but during the time it takes to travel, stuff is coming out. Could be a worn extruder/gears, could be moisture. If you want to explore that possibility, Perhaps a pressure advance test on both using the same filament roll and same gcode would be interesting.
I ran the pressure advance tests this morning. I used the same spool of Fiberon PA6-GF on booth printer 1 and printer 2. The results were very different for each printer. Printer 1 came back with a K factor of 0.016 and printer 2 came back with a K Factor of 0.023. That’s a 35% difference! I then set printer 2, the one that was ozzing badly, to the K Factor from the test and did a test print on the same part. Wow, it came out almost flawless. See the attached picture of the test part from the this morning. Problem solved…thanks for your help!
Will I have to choose that updated K Factor on printer 2 everytime I do a print or will it default to it now even after power down/power up on the printer?
Thanks again for your help!
Pressure advance is measuring essentially mechanical tension in the extruder system. So this would indicate that one of your machines might be a little more worn than the other. If you’re feeling brave you could do an extruder tear down and clean on both to try to see, but otherwise probably just reality. Replacement of the things that contribute to that system - gears, extruder motor, nozzle - as well might help but…. I dunno for sure!
Re: the software, someone else will need to chime in, I don’t know how bambustudio behaves nowadays in what it saves on machines vs profiles, but in general the pressure advance is stored on the filament selection. Copypasta for a and b imo, and make yourself a sticky note to remember to choose when slicing