Hi everyone,
I’ve had issues with layer inconsistencies/ Z banding I couldn’t solve. I suspect this has nothing to do with Z wobble, only with extrusion. I’m printing on the X1 C with the 0.4 hardened steel nozzle and hardened steel extruder. This issue is way worse with white PLA and the only helping factor seems to be reducing speeds. Even though I see this problem mostly when light is hitting the model parallel to the z axis, I’d like my printer well tuned so this is an issue for me.
Any help, tip, idea would be much appreciated! Sorry for my English in advance, here we go:
Here is what I’ve tried:
PA calibration
Flow calibration
Outer/inner wall order
Setting inner walls to the same width (0.42)
Precise walls
Infill overlap all the way down to -5%
Acceleration reduced to 3000 for inner/outer walls
Same speed for inner and outer walls, all the way down to 60mm/s
Avoid travel over walls
Cleaned extruder, nozzle, y,z cleaned and lubricated with PTFE based lubricant
Cleaned carbon rods with IPA
Switched from bambu PLA to bambu PLA matte to polyterra PLA
tried with 0.2 and 0.16 layer height, minor improvement with 0.16
Number of walls set to 3 or 4
I’ve decided to stay with normal wall generation instead of Arachne, had problems with curved geometries
After slicing I make sure that there is no variance in outer wall speeds throughout the print, when my only overhangs are text insets (0.5-1mm) I even force the slicer to not slow down by unchecking slow down for overhangs and setting small perimeters to 0. Although I listed the infill overlap setting I’m getting z banding even with no infill and 4 walls.
Here is an image with light hitting the layers parallel to the z axis. Printed in Bambu PLA Matte with 80mm/s inner/outer walls. When I apply similar settings to models with 60mm/s inner/outer walls (screenshots from the silver above) I get similar results with minor improvements.
I can’t see any periodicity so my educated guess is this ONLY has to do with extrusion inconsistencies, and not z wobble. I’ve disassembled the extruder and cleaned the gears although there was minimal filament residue in them. I tried to use the spool holder instead of the AMS, made no difference, so it seems filament gliding resistance is no problem throughout the print.
Even though I calibrated my own flow, PA, temps, when doing these for the bambu filaments, unsurprisingly I got very close to the standard recommended values Bambu provides so I ended up sticking with them. I’m unsure how the LIDAR calibration is stored from print to print, but I have seen no difference in print quality when I turned it off/on for the print.
I will post some xyz calibration cube prints where this is visible as well. Of course this issue is most visible when light is shined almost parallel to the z axis from the top or the bottom.
At this point I have no idea how to proceed so any help would be much appreciated!
What you’re seeing is pretty normal - plastic shrinks when cooling down and also I bet you’re printing with internal perimeters first resulting in the slight extrusion variations accumulating over multiple walls.
To improve your surface finish try printing with outer perimeters first. Then the extrusion error doesn’t accumulate over multiple internal walls resulting in smoother print surface.
Read more here:
If you are using orca slicer also enable the precise wall feature.
After splitting the object into smaller parts and trying further PLA manufacturers (Polymaker, Fiberlogy, Extrudr, Filamentum) I’ve concluded that this has nothing to do with filament quality. I’ve printed over 10 benchies and test cubes per filament brand with different settings to fine-tune every possible error.
So the next thing on the list was squaring the axis and trying to rotate the model, this has not helped. I am not sure though how tight the belts must be, I’m currently looking into printable models that attach to the belt/rods and indicate belt tension.
Here is what DID help and what I would advise doing if anyone gets similar inconsistencies:
If your printer is clean and you’ve gone through the list above, do:
set outer wall speed to 40-60mm/s (inner walls can stay at 150-200 without any problem)
set outer wall accel. to 3000mm/s^2
turn off ensure vertical wall thickness
turn on precise walls
outer/inner/infill order
Even though the flow values are basically coefficients when calculating flow, with these lower outer wall speed settings I set the Bambu PLA profiles flow to 0.93-0.94 (depending on Basic/Matte). This should be a confusing idea, however, this makes sense (see CNC Kitchens video: BambuLabs 3D Drucker sind ZU SCHNELL! Festigkeits- & Oberflächenprobleme lösen - YouTube). With the same reasoning, I reduced the temperature to 210°C.
With these settings I experienced increased stringings when printing multiple objects layer by layer, this however is not a problem as strings don’t go through inner walls with these wall order settings. In worse cases, this was curable with retraction settings and different Z hop movements and wipe settings.
Achieved wonderful results with Bambu PLA Matte Black with non-visible layers at 0.2 layer height. (No matter from where the light hits the model, it looks like injection molding haha ).
I will mark this as solved when I’ve made sure the printer is actually squared and this wasn’t the issue all along, so thank you for the advice!
Just a few days ago I stumbled upon this wonderful website as well, but thank you for the link anyways, that site is amazing and packed with advice and solutions!
I do not understand anything else you mentioned and why you mentioned it, as I’ve listed and even marked them with strong text in my initial post…
For the past few months, I’ve been grappling with a quality issue on the exterior walls of my 3D printed objects, characterized by overly visible horizontal lines, commonly referred to as “Horizontal Lines”. Despite scouring numerous forums in search of a solution, it appears that I’m not alone in this predicament, yet a definitive fix remains elusive.
In an effort to consolidate our collective knowledge and troubleshooting prowess, I’m extending an open invitation for all who’ve encountered this issue to join a singular discussion. This is an opportunity for us to pool our experiences, insights, and possibly, solutions, to overcome this challenge together.
To facilitate a more comprehensive understanding of the issue at hand, I’ve identified defects on my printed objects and shared photos for reference. If your experiences echo mine, or if you’ve fortuitously stumbled upon a resolution, your contribution would be immensely valuable.
Additionally, I’ve documented the issue in a video (link provided) and shared the STL file I’ve been using for my tests. You’ll find all relevant links, including the one to our forum discussion, below. Let’s unite in our efforts to troubleshoot and solve this pervasive problem. After all, there’s strength in numbers.
).
