Hi, I was wondering if anyone had such an issue and was able to solve it.
I use:
Bambu X1C
0.8mm nozzle
Textured PEI Plate
PETG HF (tried both black, white, and translucent).
Filament was dried for 8 hours at 65c using Creality Filament Dryer and stored within the container with desiccants.
I print at 0.40mm standard layer height and 0.82mm wall width.
Issue: For some reason I get these zots/blobs or tiny holes in the print. Printing a simple text cube. See photos:
Completes both standard flow rate and flow dynamics calibrations
(Wasn’t easy, for some reason PETG HF presets are not performing best).
Current flow rate: 0.98, Density 1.28.
Tried reducing print resolution from 1.28 to 0.5.
Tried reducing plate temperature to 60-65c.
Tried classic and Arachne wall generation modes
What I suspect:
Didn’t try yet to disable “Reduce infill retraction” under the Other > G-code settings.
Did not touch retraction settings at all under the Filament settings > Setting overrides.
I have not had much luck with the .8 nozzle. More zits and blobs, less effective retraction, … and due to flow being limited by the meting chamber (which is identical for all nozzle diameters) rather than the nozzle diameter it does not speed up a print significantly.
Try to see in the slicers preview if switching to 0.6 or 0.4 nozzles does increase print time of your model significantly.
Thanks for your reply.
I tried the 0.4mm and it does decrease the above issue but print time doubles, which is unfortunate. I was really hoping to get better results with the X1C for the 0.8m.
That is unfortunate. I have not seen many success stories with .8 in the forum.
It seems that the .6 is a more popular.
You could try increasing retract speed and length for the filament, but, in particular with PETG, that increases the likelyhood of heat creep and hence nozzle clogs.
So, apart from looking at 3rd party nozzles, I would assume that there are limits to what is achievable in terms of quality vs speed.
I had major issues with zits after switching to the 0.6 mm nozzle. After a lot of experimentation, I found the magic setting: retraction length. On the 0.4 mm printer profile, the retraction is 0.8 mm. On the 0.6 mm nozzle, the default retraction is 1.4 mm. After setting it back down to 0.8 mm, everything was fine.
Interesting! It seems these settings are turned off, but upon enabling the checkbox it puts the 0.8mm as default value. Will try my next print with it.
Had issues with it for the last 2 days so maybe that will move a needle. Thanks for the tip!
With regard to layer speed, yes, I noticed faster was better. However, it just seems to hide the issue. What I noticed was I could hear the nozzle popping as it was printing. The speed did not keep the nozzle from making the popping noise. Reducing the retraction did.
popping generally indicates wet filament. Heat it for 24 hours, then let sit for 24 hours. PETG-HF prints like a dream for me, and almost makes me not want to use PLA at all.
i also got rid of PETG (basic) blobbing by changing Retraction Length to match Z-Hop when retract. my PLA prints haven’t been affected by this change, so it’s now part of my default printer profile when using the 0.8mm nozzle. hope this helps!
Thanks for the tip! I adjusted accordingly and walls seem much cleaner now, but I printed a vase. Will try to print a simple shape. The strange thing is that I can’t execute any calibration properly.
I find this thread a bit odd, I tossed a .6mm on one of my p1s and ran some torture prints with the PETG-HF and could not recreate the issue. This is a bit of a shot in the dark, but when was the last time you cleaned the extruder gears? Metal and plastic ones. Is it possible there is surface contamination on your filament?
I have no idea if your filament is wet or not but wanted to correct a misconception. Drying in standard filament dryers and on the printer bed is strongly limited by ambient humidity. You can try to dry filament for months but if the ambient humidity is “high” you can never completely dry the filament.
When drying it’s very important to know the humidity in the filament dryer or printer when you pull the spool. That’s what tells you if the filament is “dry”. Weights are more conclusive but only tell you how much water came or went. By itself weight can’t tell you your filament is dry either. It’s the combination of weight difference and humidity or even just humidity that tells you if your filament is “dry” or not.
I mean, it should work fine with 0.24 and above.
I think drying the HS-PETG helped but still very difficult to get a decent calibration. I have ordered 3rd party filaments to try out as I can’t get a good quality print with Bambu HS-PETG at 0.8mm. 0.4mm was working ok.
