Hi folks, I've had my ender 3 v2 for around 2 years and it's been trouble-free until lately. Recently, I've had major issues with the first layer. I found a few worn components, so I got a dual gear extruder and replaced the nozzle, recald the esteps, bed level and z offset. Nothing I do seems to work.
The issue happens on the first layer when it first starts to extrude. The first 5mm or so of extrusion curls up behind the nozzle, then the extrusion sticks to the bed and it continues normally... Until it needs to starts a new extrusion, then the same thing happens...the curl.
I have to think it's something with temperature, but I haven't changed anything about the filament since these issues started.
You can try a few things. Add a brim to the part in your slicer. Look at your first layer to make sure the nozzle isn't too far (you can find pics online for this).
And mostly importantly!! You might not believe this, but even if all of your settings are the same, you can get finger oils on the bed over time from grabbing prints. Wash the surface with soapy water and spray/wipe with rubbing alcohol between prints. Use a glue stick or hairspray if you're still having adhesion issues. Make sure that the bed is 60-70 and that the first layer of first few layers are slow. You want a good base, that will keep the part from detaching from the bed.
I forgot that I had a spare glass bed, still in box...I put it on and tried the same print with the same results....the curl!!
I tried printing at both 190 and 200 on the head, 55 and 60 on the bed...still the same.
What are you using to clean the surface? I had bought some IPA 70%, thinking all IPA was the same. It was not. I switched to IPA 90% and that one problem went away. (I have/had other problems.)
I gotta say a big thank you to everyone that responded. Your encouragement for me to take a breather and regroup with a cool head was much needed. Thank you all kind strangers :-)
Not familiar with G10, but my PEI sheet has been the best thing for adherence with PLA I've used in the last 5 years. I've used hairspray, glue sticks, blue tape, glass, and combinations of them. Straight PEI is still better than all of them, for me anyway.
From what I read before I bought mine, smooth PEI works great for PLA, while the textured PEI is better for ABS and other types that have larger adherence issues.
What print do you use to calibrate the Z distance? Slice a square that's 1 layer thick. The exact thickness (0.2, 0.3, etc) isn't as important. You want 1 layer. If the lines aren't touching, then you're too far. If the lines are touching but you've got ripply texture, too close. If the lines are touching and it's smooth, you're just right. See this for visual examples: https://help.prusa3d.com/article/first-layer-calibration-i3_112364
That's a great article, thanks for the link. I had a suspicion that a ripple texture between lines is an indicator of too low, but it's good to get that affirmation. I usually do a real-time final cal when it's printing the skirt (micro up/down)
If your nozzle is worn flat (from scraping), it could affect your nozzle-bed gap (assuming no adjustment). If the internal diameter is worn (from long-term usage or an abrasive filament), it could cause a type of under-extrusion.
For issues with corners curling I either use a brim, or if a brim is not good for that model, I add a 1-2 layer circle at that corner in like tinkercad.
I had this happen on my ender 3 v2 recently as well, a thin layer of washable purple gluestick has solved it for me (though parts are now sometimes a bit difficult to remove and sometimes require a moist rag to get the gluestick residue off)
Thanks for that link. I wouldn't be surprised if this is my issue. I replaced a nozzle very recently and it seemed to improve things, but it quickly degraded. I also replwced the PTFE tube and likely did it wrong...though the symptoms existed before I replaced the tube. I also have a fan that has been on its way out for a while, so I could be getting heat creep. It could be a combo of all things. Either way, I have new fans on order and will be doing the rebuild. Thanks!