PETG-CF Nozzle blob

Bambu Lab P Series Bambu Lab P2S
1

Hi! I having problem with partial clogging on my nozzle (P2S) printing PETG-CF. I have done flowrate and flow dynamic calibration. Filament is dried 12 hours. The prints turn out good if I manually pause and restart to get a wipe of the nozzle. Any chance to get a G-code working for my P2S? I should add that Im fairly new to printing so adding G-codes is abit out of my knowledge. Would be great if it just wipe the nozzle without purge of filament, as it does when I just pause and start the printer. Many thanks :slight_smile:

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1 Like
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All fiber reenforced filaments are prone to create a clog.
A 0.4mm nozzle works most of the time, but a 0.6mm nozzle is always recommenced for those (same for wood filaments etc…)

2 Likes
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try first layer acceleration = 0

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Hi, thanks for reply. Sorry I cant figure out what you mean.

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Hi, I havn´t hade any problem with PET-CF or PAHT-CF with nozzle PETG-CF. Yes 0,6mm nozzle is more suited for CF material.

Would be great to get a wipe every 3 layer, but I have not found any solution, and Im not in to g-code programing Im afraid.

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at the bottom of the “speed” settings you can set accelerations of the printhead, among those there is initial layer 500, try 0

I bet that blob comes from one or more bad start of a new line that failed in the first millimeters ?

I can’t guess something different

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Thanks for explaining, and yes the build up blob is from the initial layers.

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It’s not a clog. It’s blob.

It’s caused by:

Physically: filament being too sticky and your extrusion is not accurate enough,

PETG-CF is very notorious for doing exactly this. And the reason is that it is very sticky (much stickier that Bambu’s PETG-HF, so much that it has a higher layer adhesion than PETG-HF, which is rare for fibre reinforced filaments).

This is the nature of this filament, and to solve that you need special settings on the software side:

  1. auto bed leveling must be accurate
  2. avoid low layer height, avoid overhangs/bridges, avoid variable layer height
  3. Increase infill rate, avoid self-crossing infills, use high density supports when there are overhangs or bridges.

Just FYI, when using 0.4mm nozzle to print PETG-CF:

  1. I avoid going below 0.16mm layer height. 0.12 is doable but requires high efforts on tuning parameters.
  2. I use 25-33% gyroid infill when I need to use low layer height.
  3. More layers of top surfaces to give the printer more chance to iron out issues.

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Also of course you need to clean your build plate and blah blah.

3 Likes
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Thanks for your input. I also reduced layer line with which helped a bit, but I need to check the flow rate again.

10

Hi everyone, same problem…

Did you solve it somehow?

I took out two spools and let them dry for 12 hours. I’ve been printing all week with excellent results.

Today, the nozzle is starting to smear material and make blobs until they’re large, all while still only printing the first layer.
I’ve tried both spools but no improvement. I’ve also tried cold extraction but nothing…

Any solution? Could the spools really have gotten “wet” in such a short time? About 5 days in AMS

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I’m also having troubles with PETG-CF on the P2S. The first layer is horrible and I can’t tell if it’s a Z offset issue (why is different on the P2S compared to all other Bambu printers?) or too much flow (over extrusion). PLA prints beautifully somehow, all the way through first layer to end.

What’s confusing for me is that the P1S I replaced printed PETG-CF much better with literally zero tweaks to the generic print profile, it just worked out of the box.

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I dried the filament thoroughly, so I don’t think that’s the problem. I also noticed that the first layer of supports only seems to have a higher flow. (I set support expansion to 0, but it still causes problems.)
Temporary solution: Let the first layer of supports finish, pause, clean, and continue.

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Hi. I did a manuel calibration before I started too print PETG-CF, do that, but do a cold pull a couple of times before doing the calibration. Run both flow rate and dynamic calibration.

Check out Bambu lab Academy, do your printer course and the filament course, alot of good “how too”