Sudden PETG issues troubleshooting

Hello everyone!

I used to print the PolyLite PETG and MulticompPro for a few months. And it was OK, until last week. Suddenly it started printing like this and I can’t trouble shoot the reason.

I thought that it might be a moisture adsorption to the filament, but drying didn’t work.

here are my settings for filament:

Thanks

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Perhaps there’s info in this article that may help: Bambu Lab X1 Carbon PETG Settings - Get Perfect Prints

Turn the Aux fan off.
PETG doesn’t like it.

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Tried, didn’t really improved. This is the current result:

I’ll take a look into that article. Thanks!

Have you tried any other filament since having this issue?

Good Q. How do the first few layers print with BBL PLA and std settings? That may rule out or identify a general printer fault.

Yes… Now it is MUCH better. Looks like it tried to print way too fast.
The article gave a nice start.

The good news is your printer is not stuffed. It’s just settings that need to be tamed.
Good luck

Well, looks like I managed.

Comparing to what it was, this is the progress.:

Here are the filament settings:


That looks great.

I’ve also had some ultra-thin strings with BBL PETG and haven’t sorted it out fully.

Also, after printing with BBL PETG and standard settings, the nozzle clogs and BBL PLA won’t feed through every time, requiring the needle to be pushed up the nozzle and a piece of filament to be pushed by hand through the top of the nozzle to unclog it.

Please post back if you have solved this.

I also like printed result, but 270C is more than suggested as a higher limit in the datasheet. And I’m not sure if that is something I should ignore. But on the lower temperatures I had considerably more stringing (hair-ing?) and less layer adhesion.

Regarding the clogging - haven’t had that (yet?). I do have another issue. The nozzle is so hot that after print ends and printer wipes the nozzle, the plastic leftovers are still dripping from the nozzle. Thinking if before wiping the nozzle should be cooled down to 230 and only then wiped. And use the same temp for filament purging before prints. Perhaps, a subject for a separate topic.

If you print within the recommended temperature range, is printing still ok? I’m curious why it’s set so high.

Are you using Bambu Studio or another slicer? I note settings for Print Chamber Temperature.

FDM 3D Printing Filament guide for Beginners | Bambu Lab Wiki lists:
Print temperature: 220 – 250°C
Print bed temperature: 50 – 80°C

Filament guide - build plate, nozzle and AMS compatibility including required parametes | Bambu Lab Wiki lists 240-270.

Lowering the temp will reduce the oozing out the very hot nozzle.

During print lower temperature (up to 265) results into some “holes/gaps” in outer wall layer. It is noticeable (a few mm long), but I cant trace why and where exactly is starts. It doesn’t seem to be on the “seem” of the layer.

Holes sounds like under-extrusion.

I think the high temperature being used is going to complicate identifying what is wrong. It may be compensating for a fault elsewhere, and could be misleading.

I suggest go back to standard everything: 0.4mm nozzle (if it’s anything different), standard 0.2mm profile, standard profile temperatures and extrusions rates, the works…

Then run manual flow dynamics calibration, inspect the test and update the K value.

Then print a small test block from Manual Flow Rate Tuning for better looking prints | Bambu Lab Wiki. Inspect and identify what is not perfect and change only one thing.

Repeat systematically. The test block is small, so quick and cheap to test multiple times.

Change only one thing every time. You should converge on better results.

Other things to consider: worn (enlarged) nozzle, extruder slipping (inspect inside - I recall a Wiki article on how to strip the extruder if it’s not gripping filament).

Please post back what you discover. I’m very curious. Good luck

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