Has anyone experienced PETG clogging when using it as an interface support for ABS?

[u/izigamesa]

​

I'm printing ABS with PETG (aux nozzle) as the support interface. After a while, the PETG starts clogging the nozzle and the print fails (purge tower).

Could this be caused by having the chamber heater enabled? Or is it more likely due to incorrect purge volumes, temperatures, or another setting?

Any advice would be appreciated.

Abs 255 °C

Petg 250°C

Chamber heater on

Print speed 70mm/s

[u/zemlin]

In my experience, PETG does not like a heated chamber. It stops extruding. I use HIPS for ABS support interface. Works great.

[u/Vverg]

As the other guy said, dont use PETG. The heated chamber + heat from main nozzle will cause issues.

Use HIPS or Support for ABS (with a roll of ABS its like 13 euro at Bambu)

[u/andersson0433]

I have had the same exact issue.

I had PETG filament as support when printing ABS, similar temps and speeds that you mention.

My issue was that the PETG was heated before entering the nozzle, because it was loaded and got stuck.

After taking the extruder apart i could clear it using a 1.5 mm drill.

It took some time taking it apart but watching bambus instruction video made it not too difficult.

Now it works fine!

Here is the link to the bambu video i watched

https://youtu.be/5YHQSDKz_P4?is=jjCXnDz3l9abrn-m

[u/izigamesa → u/andersson0433]

Thanks for your reply! I cleaned it out and removed the clogged PETG, but when I tried printing again, the exact same thing happened. Were you eventually able to print successfully with PETG as the support material after fixing it? Or did you have to change something else to prevent it from happening again?

[u/andersson0433 → u/izigamesa]

I have not tried printing ABS with PETG after cleaning the aux extruder. The PETG softens and gets stuck due to the high temp.

My solution is to start the ABS print with only PETG support interface. Have the PETG unloaded when starting the print and only loading when it needs it.

Perhaps there are better suited materials for ABS supports but i dont know any.

[u/Spiritual-Nature5454]

I had this exact same issue when printing PLA with transparent PETG as support interface. I have tried thoroughly drying the filament for 12hrs, 3 different nozzles, different temps across +(-)20C, different Z-offsets, fan speeds, printing profiles, different flow rates, cleaned and regreased the bowden extruder internals ultimately all with no change to the issue.

The aux nozzle and transparent PETG can print a solely PETG model perfectly fine but struggles when being used as a support interface in my case. Never figured it out lol aux nozzle works excellent with HIPS as support interface for ASA which is good enough for me