Hello.
I’m getting those weird zits on my prints. Those prints are made from PETG, and the black one is made from PC.
Using a 0.8 mm nozzle.
Filament is dry as… very much.
This is not a seam. The seam on the black one is in the corner, and the seam on the blue one is also in the corner (aligned). Those zits are not seam.
UPDATE:
Ok…
I swapped to a 0.4mm nozzle, and the result is flawless and beautiful.
I checked my 0.8mm. There is no blockage. I did a cold pull just in case. I swapped the thermistor and heater, and the same effect.
Can you tell me what setting I should play with to make my 0.8mm get rid of those holes, knowing that the same print printed with 0.4mm with the same filament a few minutes later comes out perfect?
How did you dry your filament? What dryer and what specs?
Besides the “zits” there are also alot of fine hair and stringing. Which would also indicate moisture in the Filament. Furthermore there is also alot of VFAs on the first picture. I would go and change the variables step by step. Start with using some other filament. Maybe PLA. If you still see issues check the extruder and the hotend.
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Both filaments are stored in airtight box with 1kg of silica gel with moisture content below 5% (lowest my meter reads). And silica gel is not used up based on color dye.
PC - Food dehydrator in dry room at 70°C for 14 hours. Then I printed from the Creality dryer set at 70°C.
PETG - Food dehydrator in dry room at 50°C for 6 hours. Then I printed from AMS.
Those issues also appear on other filaments. It all started at similar time.
I would check if the extruder is clean and smoothly operating and try a different hotend. Do you still have your 0.4? If so it should be a quick swap. The artifacts still look weird which would indicate more towards the hotend. Is it still straight?
I’ll switch to 0.4mm to try. (I even wanted to print those in 0.4 but didn’t wante to bother with swap).
I’ll try 0.4, reprint and let you know.
PETG likes to print slower than PLA. Since you are using a 0.8mm nozzle, You should look at printing speed since you have a 2x larger nozzle opening. The hot end and extruder can only provide so much flow.
I would also recommend a manual calibration for pressure advance and flow ratio.
I print outside walls at 30mm/s so speed should not be an issue. Also, the same filament printed fine with a full 200 or 300 (or whatever the default is) without an issue (other than color difference along z axis due to different speeds per layer).
I did calibraitons and those look great.
In 20 minutes I’ll have prints from 0.4mm and I’ll know if this is the nozzle or not issue.
Ok…
I swapped to a 0.4mm nozzle, and the result is flawless and beautiful.
I checked my 0.8mm. There is no blockage. I did cold pull just in case. I swapped termistor and heater and the same effect.
Can you tell me what setting I should play with to make my 0.8mm to get rid of those holes, knowing that the same print printed with 0.4mm with the same fillament few minutes later comes out perfect.
Turn down the retraction. Bambu’s defaults for retraction distance on bigger nozzles is insanely over tuned. I’d be surprised if they tested the settings at all tbh.
Did you change your nozzle size in your printers software?
I did. It looks like bad retraction setting as mentioned above.
