FWIW 
Hard to tell, most of it looks fairly good except a few spots here and there.
That could be grease on the print bed, maybe time to give it a wash? When PETG goes wrong for me, it’s this 90% of the time.
I use hot water and a little detergent with a lot of rinsing. Use gloves because even clean hands leave oils behind.
With PETG it’s hard to get the first layer right but if it’s good the rest of the print generally goes fine.
Molten PETG is very sticky and if you get a bit stuck to the nozzle it can build up, get worse and suddenly take out a bunch of nearby lines leading to gaps in the layer like this.
To counter this PETG first layer should be:
- Printed very slow e.g. 20mm/s
- At a higher Z offset than PLA, the plastic should flow out the nozzle and fall onto the bed rather than be squished flat.
- High bed temperature 80C / 176F
- Zero or very low fan speed for the first couple of layers
If you can see marks left by the nozzle it’s too low. The lines should have a rounded look.
It could also be wet filament, does it make popping sounds when printing?
This would be my guess as well. Those spots where it isn’t sticking look like they might be where fingers have held the plate.
I just scrub it with rubbing alcohol, works great. Is that not good?
In my experience you still want to use soap and rinse occasionally. Since you don’t typically rinse with alcohol you can just move the oils around. Also depends on what % you use.
I found alcohol (IPA) wasn’t a reliable fix for all failing 1st layer issues. I still use it because it seems to slow down the inevitable and it’s quick compared with a trip to the sink.
Thanks, I washed the bed and dried the filament, and it printed fine for the most part. The nose lifted up a bit, may be I left some soap residue there, but other than that it printed fine.
It also looks very thin, check your Z offset.
Could be multiple things. Dry your filament, in an oven or special dry box if you own one. Clean your bed with warm water (no soap or alcohol/acetone)
Use a glue stick for better adhesion.
Also, if you printer support it, you can generate a level matrix to see if it is leveled.
Why no soap? I clean with dish soap to remove oils, works great.
Residual surface-contamination.
Most people don’t understand how much rinsing is required to get residue all off things…
Dishwashers which have 2+ rinses seem to do a good job.
less than that doesn’t work.
People … seldom get anything as clean as a dishwasher can.
( NOT recommending that anybody put their 3-D printing bed’s sheet through a dishwasher: it might well destroy its surface-chemistry, given how strong dishwasher detergents are )
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I cleaned my bed and dried the filament for a few hours. The print went fine for the most part (the corner of the nose lifted up a bit), thank you
To start, your z offset is too high, your nozzle isnt close enough to the bed. Your lines should not have gaps like that, gapping in your lines means the nozzle isnt close enough to the bed to “squish” the plastic outwards and join with the adjacent line. Im gonna go out on a limb and guess this print peels off the ned very easily, and as you pull it up and off it sprt of “splinters” a bit, parts of it “fall apart” right?
If you get your z offset right, the print should come off as 1 solid piece without gapping.
Quick question:
If you run it the same time, are the failings in the exact same spots, or different spots?
Exact same spots
Bed issues, or physical issues perhaps with the wire harness to your heater catching or stretching, causing hiccups. Watch as it prints the problem areas for physical issues like it bumping stuff, or scraping on things, the wire harness, etc.
Almost same spots but not exact same
Flow issues, lower print speed 20%, see if it improves a bunch. Your nozzle is backing up and then surging causing inconsistent pressure on long runs.
Different spots
Check your z offset and watch your spool as it spins, if your spool is catching everytime it turns, it’ll inflict random jerks on your nozzle. Also check tightness on your movement system, it might be loose and getting perked a bunch by pulling on the spool as it works through the filament.
If it helps, I like Ellis’ guide for tuning my printers.
That’s useful, thank you!
Check your z-offset, it looks like nozzle may be scraping the bed. With very minimal bed leveling issues this will cause big problems. Try moving the nozzle a bit further away.
People are obsessed with babying their filaments; I’ve never met a problem that wasn’t solved by changing nozzle temp.
