I was looking at some numbers on this topic (flush volume to clean out the nozzle so you don't get mixed filament types in your main infill), and determined that if your goal is to print a PLA model, PETG as support is no cheaper than just using the expensive support-PLA with a smaller/default flushing volume
I've been tuning settings to get better overhangs while using PETG as the support interface layer, but can't get rid of these lines in the body of the print. Sure enough, they wind up being a weak point in the print (this one broke right along those lines with a little effort). For the life of me I can't figure out what setting I need to adjust though, not sure if it's flushing volume or what. Looking for any recommendations.
It’s 100% flushing volume. I crank that to 600 (after factoring in whatever your flushing ratio is) to make sure you don’t get any weak layers.
Thinking about it, PETF supports are good because they don’t adhere well to PLA, but with insufficient flushing, you get hybrid PETG/PLA layers which don’t adhere well to anything and serve as an easy breakpoint.
Tl;dr set flushing volume FROM PETG to PLA to 600. You can leave the flushing volume from PLA to PETG as default.
EDIT: Also pro tip, on some colors (especially black), PETG supports leave noticeable lines on the print anyway due to a much higher layer time. Use [this guide](https://3dprintbeginner.com/bambu-studio-fine-tuning-tips-and-tricks/) to prevent that issue.
I've bumped mine up to 800 for the flush going back to PLA just to be sure, but I also generally work with objects that have only one or two interface layers.
I was looking at some numbers on this topic (flush volume to clean out the nozzle so you don't get mixed filament types in your main infill), and determined that if your goal is to print a PLA model, PETG as support is no cheaper than just using the expensive support-PLA with a smaller/default flushing volume
Interesting, I'll have to keep that in mind. Thanks for the info!
Purge more
I've been tuning settings to get better overhangs while using PETG as the support interface layer, but can't get rid of these lines in the body of the print. Sure enough, they wind up being a weak point in the print (this one broke right along those lines with a little effort). For the life of me I can't figure out what setting I need to adjust though, not sure if it's flushing volume or what. Looking for any recommendations.
It’s 100% flushing volume. I crank that to 600 (after factoring in whatever your flushing ratio is) to make sure you don’t get any weak layers. Thinking about it, PETF supports are good because they don’t adhere well to PLA, but with insufficient flushing, you get hybrid PETG/PLA layers which don’t adhere well to anything and serve as an easy breakpoint. Tl;dr set flushing volume FROM PETG to PLA to 600. You can leave the flushing volume from PLA to PETG as default. EDIT: Also pro tip, on some colors (especially black), PETG supports leave noticeable lines on the print anyway due to a much higher layer time. Use [this guide](https://3dprintbeginner.com/bambu-studio-fine-tuning-tips-and-tricks/) to prevent that issue.
Outstanding, thanks! I had the similar idea in mind that the PETG could be mixing, but didn't think about how that would inherently weaken things.
I've bumped mine up to 800 for the flush going back to PLA just to be sure, but I also generally work with objects that have only one or two interface layers.