Looks like one area wasn’t supported. Double check your slice. My guess is that the support either didn’t build up or wasn’t modeled to build up.
Personally, I’ve never used Bambu’s basic support material, but if it is good, you should be able to use it with a zero height off the supported material and still separate it easily. That 0 height will produce a very good surface, is that what you did?
Actually, it might be useful to re-slice it and post the screen print of the settings.
That deformed area looks like it is either approaching or leaving a seam which will have acceleration or deceleration. Your Pressure Advance is probably not tuned correctly. In Bambu Studio the pressure advance is turned off and it gets set by doing the full lidar flow calibration at the start of the print. If you’re using the Textured plate it will skip this step. My advise is to switch to Orca Slicer which allows you to calibrate the PA value for each filament.
Alternatively you can do the flow calibration on a smooth plate, cancel the print and then exchange the plate for the textured and run the print. Remember to uncheck the Flow Calibration when sending the print the second time though.
Is the drooping section the section you are most unhappy with? If so, I would say support was needed. Also, I would have expected a better surface in the middle section where the support was.
This looks like it would be a very slow print if you support everything (changing filament every layer). You may be able to set the fans to aid with the sagging area, but I’m starting to think it has something to do with the start and stop point of the layer (seam), because it came out so well everywhere else.
I don’t really have a fix for that other than an ultra long print by supporting the trouble area. Curious to hear what others come up with.
Bambulabs PLA support filament works way better than regular support, but I think that the surface quality can still be improved a lot. If I would support the whole tapered section it would take forever to print and the surface quality would be way worse! The surface quality is generally very good, so I think as well that it has to to with start/stop of each layer.
What I would suggest is making a test section in CAD for only the trouble area. Maybe only 2-3mm thick that has the same curvature as the troubled area. That way you can run quick 30 mins tests and try to find settings that work without support. For example, use the modifiers to set the fans on 100% (AUX and Part cooling) and see if that helps. Maybe one test print with the seam in random spots. Maybe one test print with slower overhangs in the trouble zone.
I had the same experience initially, but now, flow calibration seems to work as expected on the textured bed. I don’t know what happened, but all the sudden, i can run it on the textured bed, it doesn’t skip it and runs through the entire process with no errors being reported.
The bambulab standard profile works best, which would be 4). The reason I initially changed the overhang speeds is because I had huge issues with printing PETG (see here). Changing the values completely resolved the issues for PETG, but as I see know are not recommended for PLA-CF.
Still: the seam looks not nice and I would like to improve that. 7) could be an option, but those tiny artefacts also show that something should be changed.
Thanks for sharing. I do remember there is something that makes the case for not slowing down for overhangs and giving better performance, but I can’t remember the details for it. Good to see the various differences.
I tried a few other settings, but have not found a solution yet. Reducing acceleration for inner wall helps, but not much (reduced from 5000 to 250 mm/s^2). I also tried a few orca slicer settings for the seam, without success.
Not sure if this is related but I’ve been fighting bad seems with obvious gaps and finally found a solution.
In the printer settings I set “Z hop when retracting” to 0 (zero)
Under Quality tab I changed Seam Gap from 10% to 1% (zero does not seem work here)
I also turned off wiping but not sure it had any affect.
After that fine tuning the Pressure Advance and wall speed gave me perfect seams. I’ve also switched almost exclusively to 0.6mm hardened steel nozzles which provide much better overhangs for me on ASA and PETG.
I can not find your 2nd setting. Is it available in Bambulab Studio?
I found that changing the wall sequence (first outer wall, then inner wall) solves the problem. The seam is not nice, I feel a difference in height, but at least it’s consistent and one vertical line.
I tried to set the seam randomly, but this does not work in combination with outer wall → inner wall. There is a lot of stringing.
