Hello everyone, I’m having issues with a print I am attempting to complete that uses white, black, and pink Bambu Labs PLA Matte. The issue is that the black colour seems to bleed into the white outer walls when printing the eye section. I’ve tried multiple different settings including increasing flushing volumes to the max from Black to White. I don’t believe it’s a purging issue because in the print, I have a control piece be printed first on every layer that is only white. So if it was a purging issue, I’d see it in the control piece which I don’t, there is no black traces to be found in the control piece. I print using the Bambu Labs 0.2mm nozzle and the model is small, it’s 9mm x 5.75mm x 11.5mm (L x W x H) and the print consists of the model printed twice in the same print (and both have the outer wall bleed issue). In the images, I’ve used Bambu Studio to cut the model for only the eyes because that’s the only part that’s bleeding and I wanted to test print without wasting material/time on the rest of the model. Any help would be appreciated! I’m at the point where I might just change the model where the eyes print separately and I just glue them on afterwards.
Printer model used: P1S
Slicer settings used:
0.08mm High Quality @BBL X1C 0.2mm nozzle profile with the following changed settings:
- Scarf joint seam: Contour and hole
- Sparse infill density: 100%
- Sparse infill pattern: Rectilinear
- Initial Layer Speed / Initial Infill Layer Speed / Outer wall speed / Inner wall speed / Sparse infill speed / Internal solid infill speed / top surface speed: 30mm/s (I find I get holes sometimes when I print such small prints with the 0.2mm nozzle fast but that’s a separate issue)
- Other settings that don’t relate to the eye section
Type of filament used: Bambu Labs PLA Matte
Settings I’ve tried:
- Increasing flushing volumes to the max for black to white.
- Increased outer wall width.
- Increase prime volume amount on the prime tower
Auto calculation used except changes Black to White to be 800 (max suggested).
From your pics & what you wrote…
You increased purge to max from Black to White & have a control piece.
Have you considered that you have to do the same with White to Black…JMO
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This may be related to three different issues, a combination of them, maybe more.
I note you have tried a few of these, showing some of those settings may help us diagnose things for you.
Flushing volumes
I would make sure these are not set too low. This seems like the most likely offender based on the supplied pictures.
Layer Filament sequence
I would then change the order in which colours are laid down per layer, and change the values per plate (in the cog icon on the right of each plate, or plate settings under the objects panel).
You will need to make the same changes for the first and subsequent layers.
Re-order the colour swatches of your filaments by dragging them into new positions, they swap with whatever was there so it will take a bit of fiddling if you have a few filaments.
Go from light (first) to dark (last), this will mean the lighter colours do not have anything to complete with from other filaments already laid down.
Visual bleed
It is possible you are getting some visual bleed, the white filament does not block out the darker colours behind it easily, increasing the wall counts can improve this.
Rule out test
Does it do this with a 0.4mm nozzle, the 0.8mm nozzle you describe as being used by its design leaves thicker lines with thinner gaps between each layer.
You could try changing the order the walls print from out-to-in to in-to-out or reverse whatever you currently have it set to.
I’ve only kept the white to black whatever the auto-calculation set it too, I can try that out though! Thank you
This is my flushing volumes
Thanks Malc! I’ll try these suggestion out! The only issue with the layer filament sequence is that it ups the print time by quite a lot but maybe I might just have to deal with it if that’s the solution
I’ll edit my post to have a screenshot of my flushing volumes and maybe let me know if you think it could be that.
Your flushing volumes appear fine, too safe IMO.
White to Black 158
Black to White 566
Those are shown in my quick tests for matte filaments.
I would normally add a multiplier of between 0.6 and 0.8 based on what I printing.
Suffice it to say, your values are greater than my safety nets.
Thoughts
Is it me or is the issue from left to right as you look at your photos?
Does it look like the colour is being dragged across?
Update
Have you tried a different infill? Gyroid for example?
Rectilinear is a variant of grid which has its own set of issues.
Yeah I use the auto calculation but I’ve set it to 800 for black to white because I first thought it was a purging issue so I set it to the max to rule that out.
Yeah I’ve noticed that too! It’s a left to right issue and I’m really not sure why, but yes! It seems like it’s dragging the black from left to right when it’s printing the white layers, because the black bleed doesn’t happen on the left side, only the right
Maybe try a lower temp on the hot end or more cooling.
See my Thoughts & Update from the earlier comment.
Hmm yeah I could try that out, maybe it will stop the dragging of the black. Do you have a suggestion for those setting numbers?
And from your posts “Update”, because I’m using 100% infill it forces me to use rectilinear but I could change the infill to be less to try this out 
Try stepping the temp down 5°c a couple of times.
Try the 0.4mm nozzle test first and the print sequence.
Okay I’ll try that out and the other tests, thanks Malc! I’ll reply with an update after they’re done!
@MalcTheOracle I tried a 0.4mm nozzle print, a 0.4mm nozzle with a print sequence going from lightest to darkest print, and a 0.2mm nozzle with the print sequence settings and unfortunately it’s still the same result for all three. I do think it’s a little bit less of a bleed but still there 
I also tried a lower temperature (200 degrees) and again with the same result.
I think I might just print the eyes separately and glue them on. Thank you for the suggestions though! Much appreciated! If you have any more suggestion, I’d be glad to try them out but otherwise, I think I’ll just separate and glue in the meantime
If you want to DM the 3MF of the eyes, I will do a test print here with the same filaments to see if I see anything different.
Click on my Avatar and press the message button.
