I am trying print a vase that is 1760 layers tall and I’m mixing Yellow and brown. I checked gradient and throughout the print it is constant 2 layers brown one layer yellow. No matter how I change or add curves the slice always shows this pattern. This makes the whole print a mustard color and no gradient effect at all. What am I doing wrong?
Using Bambu Studio version: 2.7.1.57
I am having the same issue with version 2.7.1.57
Unfortunately, I am replying not because I may have a solution to your problem, but because I too have made some strange observations when trying to use gradients on larger, vase like objects. I am also in 2.7.1.57.
Still, looking at your gradient application, I have experienced very similar issues. What did help a bit was the use of modifiers to initiate color changes.
Using a model from MakerWorld, I added the central modifier. While the model itself was assigned the basic black, the central modifier was assigned the mixed color region.
Color changes were a lot more clearly defined though than in your example to keep things simple.
The result was OK’ish. I actually quite like the look on this particular model, but it is not what I had wanted to achieve.
bug-report
This was actually the second attempt after the first try failed completely due to a problem with, I assume, the “Mixed color sub-layer” not respecting the minimum layer height.
Having looked at physical layer height limits in the past, I am well aware that as individual layer heights become very thin, the extruder is no longer able to achieve the required flow control. In fact, this is very visible when zooming in on the start (and stop) of the transition areas.
Looking at the slicer preview, I found what I assume is a further bug-report :
First layer of the gradient:
Although flow is pretty low:
Using the up-arrow to jump to the next layer:
Jumps up to layer 123 (from 121), to 24mm height.
Using the up-arrow again:
Jumps down to layer 122 and 23.98mm
So we have gcode going from layer 121 at 23.8mm to layer 123 at 24mm and then back down to layer 122 at 23.98mm…
While I put down down the first occasion (a side-table print also from MakerWorld) of me seeing this bug to my inexperience with the feature, this repeated occurence indicates to me that the gradient application may need further debugging to:
- Always respect a bottom-up layer sequence
- Respect either a physical minimum layer height (I’d recommend 0.04mm from my testing to allow a range of printers) or the user specifiable minimum layer height in the printer settings
I am aware that bug reports to Github are more effective, but as a hobbyist, I do not really use Github. Maybe @SupportAssistant could forward the observation to the relevant team for their consideration?
So @user_194329822 I am afraid that I can only offer the advise to use modifiers to get closer to an acceptable result.
But my observations indicate that there may need to be further debugging neccessary on the gradient feature.
Best wishes,
Eno
Quick update: Re-booting the laptop and running a new trial on a model that experienced this problem in the past, I kept memory usage low from the start. i.e. after
- re-booting the laptop/PC
- open the 3mf,
- remove as many parts as possible,
- re-slice just a single plate
==> Then, I got a more sensible slicer preview:
Last layer before color gradient #43 at 9.918mm:
First layer of the color gradient #44 at 10.114mm actually being two sub-layers (separated at 10.094), all displayed within layer #44.
Still a rather low delta-z of only 0.02mm for the sub-layer, but I’ll know once I get to print this plate in a few days…
At least, it may be possible to overcome that strange slicer behavior resulting in backward layers by simply restarting and keeping the system load light.
& 
Check that “mixed color sublayer” is on. It is required for gradients, and with it, each layer should have a sublayer of either color with proportional heights to the mixing. The 2-1 layers you mention indicate that this setting is not on (or that there is a bug).
Just putting this here for reference and bug-report
Gradient multi-color appears to compensate for low flow due to extremely low sub-layer heights by increasing flow through speed increase.
Unfortunately, this can go beyond the materials capability and does not currently respect settings. Rather unfortunate for PETG…
