I printed it using two materials – the main one was PETG, and the support material was PLA. PLA was only used for the contact layers. The print completed successfully, but the problem is that the layer where PLA starts separated from the rest of the model, and I don’t understand why. It’s as if the supports somehow caused the PETG layers not to bond properly, and this happened not only at the support contact area but all around the perimeter.
From my experience, if I had printed the model with PETG supports only, this problem wouldn’t have happened. In the photos there is no sign of PLA contamination — everything was printed from a single nozzle with the prime tower enabled, just as it is set in the project.
Using random PLA/PETG to support each other is very bad idea. It’s bad because it’s highly unpredictable. You should use proper support interface materials.
I use PLA bambu a difrend petg. Problem is not in suport becos suport separation was great. I thing is problem whit setup becos i print only whit petg and come ok.
It seems very likely that it’s from contamination since you are printing both the PLA and PETG through the same nozzle. If there is any PLA left in that nozzle after the filament change it’s going to contaminate the PETG layers immediately after the switch. Why not use the second nozzle?
Put em both to 900 and try again. You likely still have PLA in the nozzle when you only purge 90mm3 of it and switch to petg. You want to purge material type changes extremely well, and not just look at coloring.
Because it lacks adhesion… The problem is the support material. If you’re looking for a real solution, then start using proper support material, they are very cheap if you have an h2d.
For me, after a mis-start by using a random spool of pla, I’m getting great results with petg + pla supports.
once i:
switched to a simple natural pla ( no plus, no hf, no matte, no silk, etc)
keep your pla in one nozzle, your petg in the other
3 interface layers works for me
turn off purging into support
no amount of practical purge volume will allow you to safely switch between pla and petg in the same nozzle that I’m aware of. any amount of pla in the nozzle will make your petg brittle, as well as verse visa.
The reason for using just one nozzle is my laziness to switch it to the left one when it’s just such a small amount of material. I have one AMS 2 Pro, and loading it manually is quite a hassle.
When I get home from work today, I’ll start the print again and we’ll see. Just to be safe, I printed it purely from PETG and it turned out great.
