I have this PETG; its Kingroon Blue PETG. I can’t get it to print nicely no matter what I do. Been testing with benchy over and over.
The filament is as dry as I can make it. It’s been in the dryer for at least 12 hours before each print. I even have tried snipping the part of the filament not in the dryer to start from a dried state. The Relative Humidity doesn’t drop anymore at this point (from 19ish).
I’ve tried different temperatures from 220 to 260. I’ve tried different retraction lengths and speeds. I’ve tried with the cooling fan on/off and at a couple middling percentages. Also different speeds from 30mm/s to 45 to 60.
I tried printing a retraction tower and it fell apart after the first level.
The first layer prints more/less fine, then eventually it either just falls apart (most of the time) or produces something in awful quality.
I’ve attached images of everything I can think of from the way it looks on the first layer, to the case where its a benchy out of a horror film, to when it just fails miserably.
Printer Elegoo Neptune 3 Plus. .4mm nozzle (i’ve tried both copper and hardened steel). Besides the nozzle its stock. If I swap to PLA it prints generally fine.
I feel like I’m missing something obvious. Everyone says dry the filament, but I can’t dry it anymore 😢 .
Thanks folks (and if you celebrate: Happy Turkey Day!)
You’re severely under-extruding. This may sound weird, but try a warmer temp tower without any extrusion. You might be developing a clog mid print.
How can you tell it’s under extruded?
@[email protected] said the same thing in an earlier comment.
If there’s some clear sign of under extrusion it might be useful for my reference doc I use when trying to troubleshoot failed prints.
IMO this is the same as any other hobby. Print enough and you’re likely to run into under extrusion at some point. Similarly, I can tell if doughs and batters needs more liquid or more flower by look and touch thanks to making a ton of pizza crusts and pancakes.
The first photo in the album looks like ‘classic’ under extrusion. The layer lines are largely intact, but way less material that is necessary for a solid print is present. The print has better and worse areas, which usually indicates a clog. Combine this with the fact that PETG will clog if you use too much retraction and a user that’s new to PETG and retraction seems like a good place to start troubleshooting.
As for helping your guide, simplify3d hasn’t been a ‘cool’ slicer in quite some time but they have a decent print quality guide that names a bunch of failure modes. Ellis’ print tuning guide is the best one I’ve come across.
What’s the recommendation to fix under extrusion? I tried changing the flow in cura to 102 then later to 118… no obvious differences.
PETG isn’t very tolerant of too much retraction. Given your fine first layer I suspect you’re developing a clog as the print goes on, which would result in under extrusion. Turning retraction completely off will make it very easy to rule out as a possibility.
What should I see differently with retraction off? Like it failed but what should I look for then try next?
Did it look more solid or did print quality basically remain the same?
It pretty much self clogged a few layers in. So about the same?
Sorry to hear that. The only thing that comes to mind is potentially print speed. Your first layer is probably pretty slow. Are your subsequent layers much faster?
It must be just the blue. I figured out green: https://sh.itjust.works/comment/22401881
Upping the flow isn’t the problem then. In my experience, flow only ever varies between 95 and 105%. It’s there to compensate for thinner or thicker than expected filament. The under extrusion is caused by something else. Possibly a blockage, possibly to much drag. Pushing harder, aka more flow, might not help.