Try tuning your extrusion multiplier, I've found that petg blobs up the nozzle if you don't slightly underextrude it, running 94% on my filament on the cold side but could probably go down lower, 94% almost completely did away with blobbing issues.
this post was submitted on 20 Aug 2023
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Is extrusion multiplier the same as flow rate?
It's something that's going to be different per filament Ellis' Guide has a good write up. I found with a 0.6mm nozzle I was getting ridges and stuff in the edges noted that it built up on the nozzle and then deposited blobs throughout the print. Reducing anything that can cause the nozzle to come in contact with material helps too, I use gyroid instead of grid because it doesn't cross itself for example.
It was absolutely noticeable, I'm using Canadian Filaments - Carbon Capture PETG for reference. I'd also look at drying the filament if possible can help with stringing
As far as I know yes.
Yeah it didn't go that well. The bottom layer text became unreadable and I stopped the print
Maybe you need to dry your filament? Blobs and stringing sound like a water boiling problem.
Your retraction speed might be a little fast. 20-30mms is usually what I use. Only use the part cooling fan on the bridges. Speed can be a bit interesting. PETG is stringy. I typically print PETG pretty slow. 40-50 if I'm going for fine detail. Would probably increase the temp a bit too. That's a bunch of wild-ass guesses but it's where I'd start.
Alright I will lower retraction to 6mm at 30 mm/s.
Is your part cooling fan working? Try increasing or decreasing that.
Fans are running at 100%
Did you dry it
I reopened a brand new petg filament roll and it had the exact same issues
That doesn't mean it was dry from the factory I've had spools this year from Polymaker that were fine for the first third then had issues symptomatic of wet filament
What's your print speed? PETG likes it slow, 30mm/s for most hotends.
N4p defaults at 250mms
Not sure what that means but 250 mm/s on that model size is probably impossible. Is that your printer elegoo enptune 4? If you need high retraction distance maybe you have too much play in push fit connectors? But still not worth to look into it if you didnt dry petg yet.
Yes, my printer (neptune 4 pro) has the default speed of 250 mm/s. It prints fine with PLA. I've heard many need to increase the speed with PETG so I assumed keeping it the same speed should be fine. Maybe even increasing it.
I believe that could be your main problem. 250 mm/s could be your default travel speed. What slicer are you using? Check all your speeds (travel speed, wall speed, infill speed, etc.)
In slicer you set desired max speed, but you are limited with accelerations and actual size of the model (distance). Printing speed will never be higher than speed you have set, but it can and it will be lower most of the time, depending what are you printing. So if you set 1000 mm/s it will not print that cube any faster. Printer needs some length and time to accelerate to max speed, then slow down before next corner.
Anyway its bad idea to push speed limits while having other issues, leave that for later. In my opinion, 20-30 mm/s is slow printing, 40-70 mm/s normal speed and 80+ fast printing. 100+ is almost impossible for most printers without losing a lot on quality. Check voron, they can push 150 mm/s easy, some even go above 200. Printing faster than 150 mm/s is available for well dialed printers and experienced users. My 2500$ ultimaker barely can do that and failure risk is much higher.
My advice, set speeds at ~60 mm/s or even lower (travel speed 150 mm/s). Find best temps and settings for your filament, try to get desired quality. Try higher speeds after that.
You didnt answer have you dried your filament. PETG tends to soak a lot of moisture and its almost mandatory to have filament drier.
For PETG you dont need higher speeds than PLA for sure. You need higher temps, better dialed retraction and dry filament. If you want to increase speed, you should increase temp accordingly.
If you are unhappy with your max speed, consider switching to 0.6 or 0.8 nozzle. If you need more help its best to provide all information you have (printer model, speeds, temps, filament, any upgrades on printer, etc) to make it easier for everyone.
Well 250mm/s gives pretty good prints for me at least on PLA and I got this printer specifically for the higher rates of speed so I hope petg can handle these speeds as well. As for the filament moisture, I opened a new roll of filament to see if it will change the print but it was the exact same. One of my friends told me that increasing my height by .05mm was a little too high so maybe I should try increasing it .02 mm higher instead. I've used lots of temps and found the current one I use to be best out of all of the tests.
I upgraded to a nickel-plated nozzle, and it made a noticeable difference in PETG sticking to the nozzle less. Not a huge difference, but worth the few extra dollars.