I see these quality issue with my print. I don’t know exactly what to call it.
I have also tried printing the model rotated 90 degrees just to make sure it’s not just a X axis issue. But, the issue persists along the Y axis as well.
The rest of the print is fine. It’s only the specific area around the hexagons. It seems to be something specific to this model/geometry. I have used this filament and profile/settings quite a bit and it usually works fine.
Printer: P1S
Filament: PETG
Profile: Generic PETG
Conditions: Closed door, Standard settings
Model: Sliding Vents Riser With Led V2 by liljohn406 - MakerWorld
i think your filament might be wet,the problem maybe caused by wet filament tend to oozing more during toolhead freerun (possible water steam. pushing out the filament).
so when extrude start after toolhead freerun,the heating chamber is lacking material(pressure).
hope you can understand…
sorry for my poor english…
you may try to change the pressure advance setting or retract / extra length on restart setting to fix this problem,
or just to slow your print speed down to lower the impact of this possible oozing problem~
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PETG does often create issues if the starting seam is on an overhang since the line start does not adhere well and with it gets dragged along until it finally sticks leaving these curls.
Options I see, reduce the layer height overall or just in these areas so that previous layer to new layer line overlap is greater on these overhangs which improves the line start adhesion.
Change the Seam position settings to Back or Random or do manual seam painting to move the starting points away from these overhangs (use the slicer line type preview to see where the seams are at)
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Here an example on one of these raiser parts where the Seam start is set on “aligned” and with it starts right at the corner of the overhang (red) which creates these types of issue, Seam start on the straight section (green) would be preferred here
I have dried the filament for 6 hours or something. My AMS shows about 30C and 12% humidity.
There are some good ideas here. I will try to set the seam position to ‘back’ and slow down the print speed. I will update on how that goes. Thanks.
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Don’t be afraid to use the manual seam paint tool 
here an example where I manually painted the seam in the back between two of the hexagon holes whereas the others have the slicer automatic seam alignment.
And always remember the slicer preview display is a great tool to find possible root causes to such problems
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Is this original Bambu PETG? Then it’s the material itself. I had exactly the same issues with strands detaching. You can find lots of complaints about Bambu PETG. I compared several brands and the Bambu was far off in both cosmetic print quality as well as strength.
I think the key is reducing all speeds to 120 mm/s or less, then it prints quite acceptable although still not as nice as others. But at least you can use the spools.
if you upload the problematic 3MF file，it would be easier to locate the problem~
so that I can check the actual G-code.
@mindlessgreen - this is quite common with PETG as it has a big chance to create small bulge and to drag part of the filament usually in corners and seems , especially at higher speed as it can not stick well while extruding
As already @gx385557885 and @Alex_vG suggested and @Panamon_Creel explained one possible workaround , but i found with overhangs does not always works or too much extra effort. here is a bit if a summary assuming the filament is dry :
- Speeds - PETG less than 150mm/S max and external walls less than 100mm/S i personally use external walls at around 70mm/S gives nice shine , and internal walls around 100-120 and infill 140-150
- Flow and PA(K, Dynamic flow) - calibration main - really needs to be tuned well as over extrusion will cause this may be the PA(K) is more important . With PETG a bit under extrusion is better than over extrusion
From the photos it looks like your K factor is too low or/and a bit over extrusion, for PETG the good K factor is around 0.05 but better to calibrate it after flow calibration
Easy method to reduce the speeds with out changing the print settings is reduce the volumetric flow in the filament like down to 10mm3/s which will limit max speed to around 130mm/S
I changed the following from the previous run.
Speed:
Outer wall: 150
Acceleration:
Outer wall: 4000
Moved seam position to ‘back’
Added a brim (to resolve a different problem)
On the printer I changed the Speed from Standard (100%) to Silent (50%), but I am not sure if this does anything. It somehow resets back to 100%.
This is a new print:
This was an improvement. So, perhaps I should have slowed it down more as vladimir suggests. This is likely related to the geometry as I didn’t have this issue with other models.
@gx385557885 I am not sure how to upload a 3mf here. It doesn’t allow me.
@vladimir.minkov Yes, I did do a flow calibration a few days back and the values were the same as Generic PETG.
@mindlessgreen PA(K) is a dynamic flow is different from flow and speeds 150mm/S is high for external walls and all the speeds needs to be bellow 150mm/S
From the photo still not confident that your PA(K) or/and flow is good , but that is after you reduce the speeds, use a small cube with no top and bottom layer and on the corners you will see if major problem , or just cut out one small part of the model with hexagon and test with that
I would not play with the seams as i found that as it might help usually is not the problem
If you have not used Orca slicer would recommend you to do so as it has very good calibration mechanism and option to store it in the filament settings
If using Bambu slicer the command in the filament start code for flow is M900 K0.05; - where 0.05 is measured from manual calibration process . Personally do not use the one stored inside the printer
The last thing to check is the cooling fan settings here are mine but will take it with grain of salt as keep changing it depending on the last model i printed :
EDIT:
and would suggest to start with standard settings and one change at a time as mixing changes can be a bit confusing at least. Probably start with speeds , then with calibration , and finally with Cooling . If you are confident in calibration then cooling before recalibrating
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I did a quick test print with a test model.
On the left is the standard settings and on the right is modified based on vladimir’s first comment.
Speed:
- Outer wall: 70
- Inner wall: 200
Seam position: back
The results seem to be identical.
@vladimir.minkov Later, I will try some of your suggestions in your new comment.
I have uploaded this test model here along with the 3mf used. Note that I printed at 50% scale to keep it short.
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It doesn’t make much sense to print outer walls at 70, but inner walls still at 200. if the inner walls fail, the outer walls will fail too, no matter how slow you print them.
I will try to print your test tomorrow, if i find the time.
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@mindlessgreen Here is a public holiday and the day just started , i just started the first print at 100% your test model and send you results later , and if anything i needed to change from my original suggestions but yes @Alex_vG is correct 200mm/S is high for inner wall or infill all speeds bellow 150mm/S.
Here are the results from the file you sent :
Left is well under extruded(0.94) PA(k)=0.053 and external speed is 120mm/s / 255C print / Random seem
Right much better result is just a tiny under extruded (0.96), PA(k)=0.038, aligned seems 70mm/S/260C print
I almost never print PETG at the exact measured extrusion flow , my one is 0.99-1.00 and go up to 0.97 in rare cases using 0.98 most often 0.96-0.97
The second result is much nicer but for bets result in this case . should have used
probably PA(K) = 0.042 and the extrusion is probably ok , and may be the temp needs to be 255C . That is for my ESUN PETG
For all the settings i have uploaded 3MF file to makerworld but it strips the K factor custom command M900 K0.038; from filament settings which is used for Bambu studio to over write the PA(K ) in the filament settings
Please check and compare all Hex hole test by mindlessgreen - MakerWorld
Also note the cooling profile and speed profile
Let me know if you can not get the Print profile to copy Images of all the settings here
Also i tend to use seams 0% distance and wipe on , but even with 10%-5% distance and no wipe no problems in general just the way the seams look and model dependent
Left one using 10% seams no wipe random , right one uses 0% wipe on aligned
EDIT: some ringing/ghosting in the print - nothing to do with settings something to do with second printer on the same bench printing in parallel , but if it happens usually acceleration is high or the printer can not compensate well enough for unstable bench , or tensioners needs adjusting
is that small bubbles in your print?
I noticed the defects is mostly on the overhang corners, so it might have something to do with the overhang settings, could you take a screenshot on these overhang related settings? It might be helpful~
@gx385557885 No no defect on the right print, it is my photographic skills and bad camera it enchases any reflections and shades , in reality looks a lot better than the photos
not sure for which one left or right print you are talking for bubbles and what do you mean if you mean the ghosting( small vertical waves) more prominent of the first print, it is on both mainly caused from second printer working in parallel (not Bambu)
The left print is not ideal the second one is close to the best X1C can print with PETG , but as mentioned PA(K) factor needs to be increased a bit and reducing the accelerations and slightly slower speeds of infill/inner low it will be marginal better, but i will leave that to @mindlessgreen
Surprisingly no overhang issues on BambuX1C but that is only 45 degrees the actual issues are starting after 65 close to 75
@gx385557885 please feel free to print one model and send the settings and photos you can share in the mindlesgreen model
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