Why PETG bracket broke easily?
Hi, I was printing U-shaped bracket of 2mm thick using PETG. In the past, I printed a similar one of the same thickness in PLA and it was not very easy to break. However, for this one made of PETG, after I removed it from the printer, it broke at the base (bottom of the U-shape) while I was removing the support material from it. How come it is easier to break than PLA? I though PETG were stronger.
RE: Why PETG bracket broke easily?
It will depend on your printing temps, whether you used cooling, and finally the PETG formulation.
RE: Why PETG bracket broke easily?
Thanks. Which cooling are you referring to? What is mean by "PETG formulation"? I just chose PETG from the prusa software. I bought the official one from Prusa.
I tried to print the one in the photo three times but always got a crash error when I checked the printouts. What is this crash error? Nozzle hitting the printed object during printing? What is wrong with the printing? Please let me know how to fix it.
RE: Why PETG bracket broke easily?
Peter-c20, regarding the breakage - could also be damp PETG - I found that dry PETG prints better than PETG that has absorbed moisture (which it will do over time).
Cheers
Digbat
TANSTAAFL
RE: Why PETG bracket broke easily?
@neil-t
Thanks but this is a brand new filament. I just opened the box and used it.
RE: Why PETG bracket broke easily?
Peter-c20, ah, in that case, that possibility, eliminated.
Cheers
Neil
TANSTAAFL
RE: Why PETG bracket broke easily?
@neil-t
I will keep it well preserved. Thanks
RE: Why PETG bracket broke easily?
[...] Which cooling are you referring to?
The part cooling fan. PETG is prone to being brittle if you apply too much cooling. Ideally, print PETG with no cooling for best strength.
[...] What is mean by "PETG formulation"?
PETG from different manufacturers will vary in terms of what temperatures and speeds work best for part strength. You may have to do some small test prints to determine what works best for your part. Also, part orientation matters. FFF printing produces "grain" much like wood. Parts will be strongest when force is applied perpendicular to the layer lines.
I just chose PETG from the prusa software. I bought the official one from Prusa.
That's good stuff. There are 2 Prusa PETG profiles: Prusa PETG and Prusament PETG. Be sure to select the profile for the filament you are loading as they vary in printing temperatures.
I tried to print the one in the photo three times but always got a crash error when I checked the printouts. What is this crash error? Nozzle hitting the printed object during printing? What is wrong with the printing? Please let me know how to fix it.
If you are over-extruding or filament piles up on the part, it can create blobs that will result in a crash during printing. Looking at your pic, I'd try slowing way down (50%) to start with and see if that helps. If it does, a bit more heat or slower speeds may be necessary.
If you'd care to save a project 3MF file with your part and settings, zip it up and upload it here (attach to your response), we can look at it in more detail. I'm doing a LOT of PETG printing right now.
RE: Why PETG bracket broke easily?
Thanks. How to print the PETG with no cooling? How to slowly way down of what? How to do that? How do I add more head or slow speed?
In preheat, there is only one option for PETG.
RE: Why PETG bracket broke easily?
Even I chose PET in the LCD screen of the printer as the filament, when doing first leveling, it asked if I have load PLA. Is this a bug with the program? Am I supposed to ignore it and use PETG during both first leveling and printing?