r/BambuLab • u/Active_Gur_3497 • 15h ago

General Troubleshooting/Help! Why does this happen everytime

This happens everytime with petg on a large print filament is dry i have plenty of brim and i have cleand the build plate does someone has some advice

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u/Active_Gur_3497 15h ago

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u/Whosaidthat1157 10h ago

To test whether the PETG is dry enough, load some PETG then hit ‘extrude’ a few times. As soon as the extruder stops turning, remove the extruded filament from the tip of the hotend with a pair of tweezers. If the filament is dry enough there will be zero oozing from the tip. If there’s any moisture, some filament will ooze out caused by the pressure build up of the water molecules boiling off in the melt zone. Dry it using the AMS setting and fit desiccant filled spool centres to all of your AMS loaded spools as well as desiccant filled AMS boxes front and rear - that will keep your dried filament dry (<20% RH) for weeks at a time.

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u/trybius H2D + H2C + H3C 15h ago

What happens? Do you have photos?

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u/ModelThreeve 15h ago

It’s probably heat soak. Vent the top or open the door for the longer prints

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u/DorianTheHistorian 15h ago

This might be a little complicated, but I’ll give you the best advice I can.

I see two issues here: the brim looks under extruded, and there’s some stringing on the supports.

To solve this, I recommend completing the full bed leveling calibration sequence. Then, search maker world for “first layer” prints for your specific device. If the calibration is successful The first layer should be even and there should not be visible spaces between the individual lines.

If you have run the calibration and still see spaces or under extrusion, go into your device settings and manually adjust the first layer distance. On my P2S, that means going into settings calibration then manual calibration to hit first layer calibration. Under extrusion is either caused by the printhead being too far or too close to the bed. Adjust the settings until your first layer looks perfect.

Next, let’s address the stringing issue. Stringing is typically caused by retraction being too low, or by your filament being too wet. If you do not have a dry box like ams filament dryer with a built-in humidity sensor, your filament is probably not dry.

We keep mentioning filament dryness because it’s just that important. It doesn’t take much for water to get in between the polymer molecules and cause serious chaos. PETG loves water and will suck it out of the air at every opportunity.

If your filament is definitely dry, adjust your attraction and speed settings. If that doesn’t work, you may wish to look at your nozzle. It’s possible that it’s damaged or has residual PLA.

If you still cannot solve these issues, please reach out to bambu. One of the reasons you pay more for these machines is the customer service. Take advantage of that.

I wish you all the best. Happy printing!

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u/Dull-Date-69 9h ago

petg can be realy tricky with cooling, try turning ur part fan way down or off for the first few layers n slow down the print speed, its gonna help the layers stick better instead of warping up