I’ve had my new P1S printing daily for the last 2 months just fine, but for some reason when I’m using Bambu Matte Charcoal (#11101) some middle layers will fail entirely, printing just unattached strings for a few mm then resume fine.
I’ve gone through about 10 spools of various Bambu PLA, and this has only happened 3 times, all on the Charcoal #11101 PLA.
I also tried this one with the preset from the file and didnt change anything and it also failed. This photo is technically upside down but where the supports touched you see some of the circular lines are failed or missing.
I also tried printing the case from the radius gauge project here Radius Gauges by MIGo.Lab - MakerWorld
This one had about 2mm fail completely. Theyre just strings and not even attached to each other. Then the print finished just fine and kept going after it recovered. This one also uses the default profile from the model.
Has anyone seen this before? I’ve had printers for about 7 years as a hobbyist and never had this specific problem before. I thought it could by something on the z screws causing layer jumps but this fails at different heights on all 3 prints. I also checked the z screws seem fine.
I’ve even done calibration and stress test prints and they all pass, but only long prints with Charcoal color have this issue. I’ve done many overnight ones with white, black, and pla silk and they all are good.
Also worth noting I use 2 AMS’s and both charcoal rolls that failed have been in different AMS’s.
The filament is also stored in a dry box.
This photo is could be classic symptom of a filament path “choke”. I would wager that this is likely due to binding at the spool or elsewhere. To verify this theory for yourself and see how this can affect a print, try this experiment, print a 100mm cylinder, and midway, apply hand pressure to the filament entering the PTFE tube, then release after a few layers. You should observe the same issue, indicating interference in the filament flow.
Troubleshooting steps:
Have you tried a failed print without the AMS?
Have you checked for feed snags or spool binding? Start with step 1 and ensure the PTFE tube is correctly seated and not binding.
Have you rotated the model on the Z axis to alter X-Y nozzle movement and check for head snagging?
Can you reliably reproduce this error at the same location for the models you displayed?
And the most obvious question; have you tried another filament that is NOT Bambu and not matte?
The other unlikely possibility is that for whatever reason, the slicer algorithm is getting confused using the tree supports. While less likely, one way to prove or disprove this is to change the supports to normal and see if that influences the print. Even if it fixes the problem, it could still be just covering up a feed problem stated above so don’t rely upon that remedy as conclusive proof.
As a side note, if you haven’t had much experience with matte filaments in general, both matte and silk, particularly Bambu Matte and Silk, are absolutely horrible filaments to use for something structural. Plastic is naturally smooth and therefore shiny; to reduce the shine, filament makers dope the formula with a material that makes the surface less smooth. Often, it’s cornstarch, as some makers brag about being “organic” or “eco-friendly.” The problem with that is it interferes with layer adhesion, resulting in weaker parts. Bambu silk has been shown to also stain smooth plates and leave behind permanent marks that ruin future prints if one is using a smooth plate to get a smooth bottom surface, the image of previous prints will be transferred to the new model. (They leave that fact out of the brochure! )
Thank you for the ideas!
I disconnected the PTFE tube from the back of the printer and manually fed the filament through then printed a cylinder while pinching the exposed filament to try and choke the filament feed and I couldn’t get it to fail. I don’t think it was binding because the extruder was doing a perfect job of fighting my resitance. I also dont think its binding because other filaments in the same AMS feed just fine, even accounting for moving this roll to another slot.
I have not tried without the ams yet, I might re-try the part when I’m at my printer next.
Yes I have checked
I have not, but how is it possible for the print head to snag? Isnt the print head always above the print?
No I cannot. I reprinted one of the parts and it came out perfect. This just happens sometime and only with this one filament type.
I have tried Bambu PLA basic, silk, and matte. I have not ran other filament brands through my P1S. I do have a bunch I can try that work on my Anycubic Vyper that I can test out.
Also this has happened on a part with no supports. My last screenshot in the post shows its just walls that failed.
I’ll keep experimenting and reply again after some more tests.
Thanks again, and also suuuuuuuper huge thank you for the PLA Matte warning. I was so confused why some of my parts had an ugly first layer, it looked like some giant faded white splotches and now I know why. Its from the white matte pla I used. Good to know I already ruined 3 print beds lol
By snagging, there could be contributing factors like the chain hanging up, but in all fairness, that would cause momentary “voids” in the print rather than entire layers, as seen in your example. However, it’s worth ensuring that the chain moves freely and isn’t catching anywhere. Large diameter test models tend to highlight this defect. I suggest using a 150mm round cylinder in Vase mode, which will print a single wall. It doesn’t use much filament and is relatively quick. If you have any path issues, the “Spiral Vase” mode is very unforgiving test and will reveal filament flow issues quickly.
Here’s the setting, just in case you may have not previously experimented with it. It only works on round or simple models, not the mask you showed. My example uses Orca Slicer, but the feature is available in Bambu Studio as well.
Did you check the PTFE tube for wear? While that is unlikely, you never know. This is particularly true if you have used any abrasive filaments over time.
Here’s an image of what to look for when inspecting for wear.
Had some more confusing issues with printing and made another post: P1S got bricked while printing, took 4+ power cycles
It was discovered in that thread that the microSD card that came with the printer was sometimes having issues when printing long prints.
I have replaced the microSD card with a SanDisk one and reprinted everything that failed and have been printing with the Matte Charcoal color again with 100% success rate.
So the answer is that this was a failing and eventually corrupted micro sd card.
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