Hello All,
I have been printing steady since the A1 came out and have had no issues. The past couple of days I have been getting these horrible layers just on the front of my prints of these boxes. I have rotated the prints, moved to the front/rear of bed, tried different size boxes, different filaments and it makes no difference. It always happens on the front surface only. All other sides look good. I have been printing these with the same files on my A1 Mini with no issues, so I do not think it is a bad file issue. Any thoughts or ideas. The filament I am using is good, dry, and used before without issue (not to mention I have tried different ones and this still occurs). I use the generic PLA settings, which have worked 100% for months and months without issue.
Great to see what you’ve tried, as that potentially rules out a lot of things.
The first layers seem to be somewhat fine - also for the front. But it looks like print speed and/or acceleration is very high here - fx. 400 mm/s+ and 12,000-15,000 mm/s^2 acceleration? If that is the case, simply dialing down the speed can help. But there are (at least) two issues with this theory, and one is that you write you run at stock settings for Generic PLA - which is set to just 12 mm3/s volumetric flow, which forces filament to be printed at very slow speeds. High acceleration could still be an issue though.
The second reason reason is that since the other surfaces look better, there’s also something else going on which may not be speed related at all (although high speeds always amplify any issue caused by other things), and one possibility could be some sort of air movement, which the A-series are more vulnerable to, since they’re not enclosed.
So, to help diagnose the issue - I’d like to know:
- Speed/acceleration settings
- Max volumetric flow under filament settings
- Number of walls
Also; can you try to run a Calibration Vibration test? If you have any lose belts, it should warn you during/after this calibration has been done.
Hi, looking on the rigth side look like you have a seam there, look like underextruded so much that seems to be another seam. maybe the bowden bend too much when the tool head is there? Is the gcode ok? had you check if, there, is everything ok?
Thank you for your information. Not being in front of printer currently I can answer a couple of your questions. Yes setting has been left at 12mm3/s max volumetric flow. I am not sure off the top of my head on acceleration. I did, today even, run the whole 20min calibration for vibration, bed level, and noise cancellation (?) I think. Went through process, no errors.
These are drawer organizer boxes, thin walled, nothing fancy, easy quick print. So all sides are identical (outside of length if not a square). I would just assume if it was a volumetric flow issue it would be on more sides. Same with speed since all sides are doing the same printing. Someone mentioned in another reply about potential for bowden tube (assuming PTFE is what was meant since a direct drive extruder) could be bending too much causing an issue, but I do not see that either as that extends left to right and the bed is making the forward movement. So if that was a potential issue I think the back of the print would suffer the same.
Also, I am not sure I was able to word this properly. When I say “front of print” I do not mean there is a front on the print itself that I am moving around. I guess it might be better if I say the “front of bed” is the issue and anyway I turn the print anything facing the front of the bed is what get’s knurly.
Could it be a bed leveling issue? I have run the configuration, but should I go old school and make sure it is flat as can be with paper test?
WHY JUST THE FRONT FACING (of the bed) is the biggest problem I have with fact finding. Everything I can think up would have more effect on print all over, or first layer even. I have swapped nozzles (running stainless 0.4 BTW), cleaned nozzles, cold pulled nozzles, tore apart extruder and gears to see if any issue, none. I am straight up out of ideas!!!
Oh sorry, I have also printed with 2 and 3 walls…no difference between the two.
Wow - that’s cool how you’ve done everything one could ask for in terms of troubleshooting. It eliminates the usual suspects, but that’s also where it becomes tricky.
A manual old school tramming wouldn’t hurt, but I can’t see how it would be this issue, as the bottom layers are fine.
And yes I understood the meaning of front as being front of the bed perfectly fine, thanks to the good descriptions you gave in your initial post.
What perplexes me the most is how it looks like the corners become rounded and overall more turbulent. As if a high acceleration or jerk caused it, but jerk isn’t a tunable value in Bambu Slicer, and acceleration probably isn’t all that high. It’d also affect the bottom layers and the entirety of the shape - especially since it’s a drawer.
Filing a ticket with Bambu Lab tech support is probably one of the best bets at the moment.
I’m curious though; which filament do you use? Not that I really think that that’s the issue, but I’m also beginning to be out of ideas….
That the problem is on a particular face points out to a focused problem, I think.
General parameters change the behaviour of the printer in all the perimeter, it’s not by-face controlable.
Do you change something in the room?
Any window that was closed is now open?
A door?
Any air stream?
Air conditioner/heater?
Just giving ideas.
I buy Kingroon filament mostly. I have gone through probably over 120 rolls of it, never an issue. I just print for myself so I am not worried about “top quality” but it really has been a great filament for the price.
I ordered a new round of nozzles for both my printers. When they get here I will swap out and just do a tramming to see…hey can’t hurt! I do not think it is either one of those issues, but just keep working down the list.
Nothing changed in the room. Same temperature, same humidity, same season outstide, no new fans that haven’t been there the entire time.
I’m (almost) at a loss then. I use Kingroon myself, as of fairly recently - although I’ve already run 4 kg through - and since the first roll, I’ve been in love with their price-to-quality and performance ratio. The reason why I asked was that there I’ve met Bambu Lab users on Reddit who had to run their PLA PRO from different manufacturers, at a mere 8-10 mm3/s. Well below the treshold of your average PETG… and they had something resembling your issue - although not quite, as theirs was uniform throughout the model and not dependent on side.
Oh btw. I got curious about the air flow of the A1 toolhead. It seems like not a lot of airflow will hit the “front” of the print. So maybe there’s either something stuck in a cooling vent/duct or there’s a misalignment? You can try activating the fan without printing and hold some toilet paper with a pincer, and bring it close to see if the air flow seems even or if there are dead spots.
This would harmonize with the first layers looking and the others not, as speed ramps up and the cooler activates.