Any idea why my prime tower turned out like this?
I set the PETG as the support interface.
Top z dist. 0
Also, I was under the impression that PLA and PETG doesn’t bond very well but they pretty much fused together. Is it because the PLA is matte?
P1S with AMS.
Black matte PLA & Grey basic PETG.
It’s looks like that because you used PLA & PETG.
I’m pretty sure that each time the PETG went down it just got dragged.
Then the PETG stuck to the PETG where ever it could.
Then the next layer of PLA stuck to the PLA the the PETG didn’t cover…this fused the tower.
Never ever ever use PLA with PETG! At least from my experience.
Using PETG/PLA as a support interface is a pretty common occurrence with Bambu printers. Lots of people here have had great success with it.
I’ve been told PETG is a great support interface for PLA and vice versa.
It might also be nozzle temperature differences.
Hmm. I’ve seen many people using this combo for support interface.
I thought about this too and did a quick check and I think the printer automatically adjusted the nozzle temp in between while pooping. But I do need to double check this.
What brand of filament is it?
Kexcelled matte black PLA and basic PETG both same brand
One feature of the prime tower is to capture any oozing. Looks like it is doing its job 
PETG as a support interface for PLA works incredibly well. Hardly any bond strength for easy removal but just enough bond strength to keep objects in place during printing.
I’d hazard the guess that under a bending load, the prime tower will break quickly at one of the PLA/PETG interfaces.
That’s not what the user asked, he asked about the prime tower.
I think you & I are the only users that actually read the 1st post.
Having a prime tower made out of a mix of materials that don’t stick well together is not ideal. It would be nice if there was an option to have seperate prime towers for the different materials, but I appreciate that this could result in lots of extra material swaps unless something like ‘no sparce layers’ was re-enabled within BambuStudio.
I think it would be possible to do this within a gcode post processing script - but ideally it should be built into the slicer. I think this should be raised as an enhancement request on Prusa/Orca or Bambu Studio.
Update - have raised this enhancement request on BS - Separate No Sparse Layer Purge towers for different materials · Issue #5122 · bambulab/BambuStudio · GitHub
