Layer separation between 1st & 2nd with PETG
Hello
I have a mk3 and i'm trying to dial in my petg print settings.
I got PLA to work really well, i've spent a lot of time on bed leveling so i get good PLA prints regardless of where on the build plate an object is.
But with PETG it is not quite as good.
I printed a 3d benchy using slicer pe and with the stock "Prusa PET" filament profile using orange prusa petg
First of all, bed is completely cleaned with some soap and water, then some IPA and finally prepared with a bit of glue stick.
The benchy is mostly ok, first layer is laid down ok and doesn't peal off or anything like that but once the print is completed and i remove it from the build plate (after it is cooled down to around 30 degree C) some parts of first layer separates.
Mainly the outer border of the bottom of the bency and the outline around the text ct3d,xyz
It looks like some areas of layer 1 and 2 is not sticking together properly but not all and rest of the benchy looks ok.
Any advice on what settings to change to fix this?
i'm guessing on the temperature of first layer, perhaps increasing first layer temp from 230 to something a little higher.
Re: Layer separation between 1st & 2nd with PETG
My well functioning PETG temp settings are...
1st layer
Extruder 240
Bed 85
other layers
Extruder 245
Bed 90
Fan
min 40% max 75%
bridges 80%
disabled first 3 layers
You can dial up PETG quite a bit higher in temperature than where you seem to be currently.
For finer detail, I go up on the fan to 50/80
For parts needing higher strength, I extrude other layers at 247
These settings have worked reliably with Amazon and Stronghero PETG for me.
Re: Layer separation between 1st & 2nd with PETG
Thanks, i will try those settings and see how it works.
There is an additional problem i had with PETG earlier when i tried printing some smaller parts.
On the model there was one area with a small circle (or cylindrical pilar) and every layer started and stopped in same place and each start/stop left a little blob of extra plastic.
Eventually the extruder started catching on it and pealed it off the build plate forcing me to cancel the print and starting over.
I think i have less of those plastic blobs when extruder starts and stops now but i'm not what the caused is.
Hopefully the higher temperature makes the plastic melt a little better and not leave blobs behind as much.
Re: Layer separation between 1st & 2nd with PETG
Those settings worked better and the layer separation problem seems to be solved.
I did notice that the text on the benchy at the bottom is more squashed than with pla
I wonder if maybe petg should be printed a little higher up from the build plate than pla.
Re: Layer separation between 1st & 2nd with PETG
I lift my z height up about 0.030 when printing PETG instead of PLA otherwise it sticks well too good to the PEI. (For PLA, I usually squish it down so much that the first layer lines disappear, but I wouldn't do this with PETG!)
I also had the problem with separation on the first layer outer line. For me the problem was that I printed with PLA before the PETG print and didn't purge the nozzle enough. Minimal amounts of PLA mixed with PETG makes the layer addhesion verry bad. So when switching filaments and the printer asks if "the right color is extruded correctly" I answer two times with "no" so that the printer extrudes three times and the Nozzle is completely PLA free.
For the PETG temperature ...
I print PETG as hot as I could (just before it starts bubbling) which is somewhere arround 240-250°C for the filaments I use. This way I get the best layer addhesion and transparency, but bridging and stringing might be more problematic.