My prints up to this point have been okay, but not great. Serious stringing seems to be an issue here, and one of the things I’ve notice is that the further along the print goes, the more it seems like the print head is almost grinding into the print. To the point where if I’m printing something like a minifigure, it will get ripped apart mid print. Am I overextruding? Missing z steps?
Filament is Overture PETG, Nozzle is 230C and bed is 80C. I have it in an enclosure. I’m running it from a laptop set up with Cura.
What your picture is showing is not stringing, it appears to be an utter failure of layer adhesion. That indicates to me you are printing too cold or, more likely, too fast for PETG. What you’re grinding against is most likely layers of the print that have not adhered to the layers below.
Try slowing it down and do a test print. See if anything improves.
Hoo boy I had it going way too fast. I had it moving at 150mm/s. I very strongly suspect this is about 90% of my problem. Layer quality already seems vastly improved a few layers in at 50mm/s. I very much appreciate the insight!
I agree that it’s probably a speed issue. When I first started printing, I was seeing just how fast I could go with PLA and tuning for that. Decided to try out PETG a few months later, and it was a disaster. Layers weren’t bonding properly, and the filament would bridge across points on the print. Once I backed print speed down to 50, I started to get much better results.
Word. I’ll give that a go, thank you.
PETG is picky about layer heights and speed.
Thick and slow for PETG. I usually double my layer height vs what I would print in PLA. With my .6 nozzle I print with .3 layer and cut my speed down to 50% for the first layer. Since you said it happens mid print you might be printing too fast for the first few layers and it is getting too high because the layer is not cooling enough and it starts curling. You can also try reducing flow if your nozzle is worn and it’s allowing more plastic than the sclicer expects which will cause too high layers and scraping.
Oh and it sounds like it’s too hot too. 80° bed in a enclosure could cause the chamber to get too hot and not allow the layers to cool fast enough and so you will see curling while printing. Lower the bed to 40-50 and monitor chamber temps. Maybe open the doors a crack. You only need an enclosure for PETG if the room is drafty.
Interesting, so best practice is to increase layer height for PETG. Seems good to know
I haven’t had issues with curling but the enclosure is pretty new. The room is pretty variable with temps. The windows are old and maybe a little leaky.
In addition to what dual_sport_dork said, it looks like you’re overextruding a bit, which might be causing the head to run into the curling up regions
Do the same prints come out fine in PLA? First thing I do with a bad PETG print is to see if it comes out ok in PLA. This helps determine if it a nuanced thing with the filament, a problem with my gcode, or a mechincal machine issue (belt tension) xyz calibration, etc.
I haven’t run PLA on this printer. This is actually my second one, I modded my first one to the point of unusability. Maybe starting back with PLA is a good idea.
For grinding, try calibrating with a calibration cube and calipers.
For the stringing, try calibrating your extrusion steps. If it continues, try dialing back your temp 5° at time.
There is a process for retracting slightly between hops, but that may be a slicing option.
I’ll try dropping temps and see what I get. Thank you!
