Please explain to me how to succesfully print PETG on a PEI build plate.

[dbhosttexas]

Okay I am going to come right out and admit it. I am clueless when it comes to PETG. Never printed with it before, and, well not only does it not stick to the build plate, it wants to run away from it... I have / use 2 different printers.Both Voxelab Aquila series printers.Aquila (Original) with a PEI build plate add on which really did help my PLA printing.Aquila X3 Max with a factory PEI build plate (And a giant one at that!). PLA will slide off into the print if I don't do the glue trick to give it something to bite onto, but after tons of successful PLA prints I think that works pretty nicely...Again through, PETG, not so nice...I am using Voxelmaker as the slicer for now. I think I found a tutorial on how to set up a custom printer profile for unlisted printers in Cura. I will be moving to Cura fully in the future, but for now, I am stuck on Voxelmaker doing the learning curve thing to get off of it. Given the limitations of the slicer that works for the X3 Max, could you please tell me what settings I can use for Voxelmaker to make this happy? Or maybe how to get a working profile in Cura under a different make / model name like the Aquila just runs under the Ender 3 profile...Is there something like the purple school glue trick that works for PETG? Should I be using the smooth or the textured side? Should I be using a raft, a brim or?Just shy of coating the PEI with super glue what can I do to make this work?

[airscapes]

PETG sticks to anything if the starting Z axis offset (gap between nozzle and bed when it is at Z0 is within the proper parameters. I use to print on heated glass, and removing the print was the issue, it ripped a chunk of glass out of the bed. PEI is what I use for PETG and lower my bed temp to 65C and still have issue with the print ripping up the PEI. I have started to set my Z offset to .03 higher than it should be.
Sorry I can not explain how you fix your printer just trying to convey that having PETG stick should not be a problem.
I would assume you have cleaned your bed with alcohol.
BTW you may want to look into Prusa slicer as it is one of the best maintained free slicers.

[dbhosttexas]

I have tried with both printers. On the Aquila I just follow the regular leveling process, I.E. set the bed height so at each corner I can just start getting some dragging resistance on a piece of standard printer paper. On the X3 Max I do auto level, then auto home to get the print head to Z0 position. I then set the Z offset to again, where I can just get some dragging on a piece of printer paper.

It works swimmingly on PLA, but PETG not so much.

Temps are set to the specific PETG MFGs specs, typically around 230c on the hot end, and about 70c for the bed. Of course I am getting the specs from the product details on Amazon...

The PEI plates get regularly cleaned with alcohol wipes.

[airscapes]

and what happens when the print starts.. filament balls up or just does not stick? Have you run cleaning filament through your hot end after the PLA and before the PETG? I really do not know what else to tell you, there is virtually nothing different between PLA and PETG other than temperatures.. really and truly.
What size is your nozzle and what extrusion width do you use? Do you have a digital micrometer?

[dbhosttexas]

Good questions and something I have never heard of. Give me a second to respond...When printing starts it lays down a nice even line, makes a turn, makes a nice even line, so basically outlining the object, let's say for example a cube. By the time it gets about 2/3 of the way through the third side of the first line, it is pulling the first and second lines behind it like a dog following on a leash, No balling, no fuzzing, just won't stick.I did manage to hose my PEI sheet on the original aquila as leveling got way out of whack during a print and managed to ram the nozzle into the sheet. So brand new sheet... Am concerned about the leveling adjusters backing t hemselves off again though...Nozzle is .4mm, extrusion width is whatever the default in Voxelmaker is. Not a lot of options that I saw there, other than path width which I would think would be the same and that is .4mm as well.Yes I do have a digital micrometer. Lastly, I literally just heard about cleaning filament yesterday when I opened a box of new glow in the dark filament for a Raspberry Pi case I wanted to print. Never heard of it before, no clue how to use it.PLA is sticking well, PETG not so much. Pretty sure I am doing somthing wrong...The machine is new on the X3 max, the PEI build plates on both are new. So that might have something to do with it.I guess the first place to start. Smooth or textured side?Purple school glue or no?Use the Voxlemaker temp defaults or adjust to what the PETG MFG lists on the Amazon product listing? The bed temps are very much different. By about 20 deg C.

[airscapes]

Ok, so cleaning filament is just that. When you remove the pla you heat the nozzle with the nozzle way above the bed and you extrude 200 or 300 mm. Then you remove it and insert whatever you are moving to, in this case PETG. Run 300-400 mm waiting 30 seconds between extrudes so the cleaner will get removed. If you do this the nozzle will never clog.

I would set your bed to 80C normally 70 is fine but you are having an issue.
I am going to attach a file if it will let me. This is a 2 walled square that is 3mm tall with wall thinness of .4mm.
Print this in pla using a layer height that will cleanly divide into 3mm. With that size nozzle and the issues you are having I would suggest you use .3mm layers.
Once printed measure the height of the walls, should be 3mm+-.02. Then measure the thickness of the walls, should be .8+.04 or so.. If the walls are 3mm tall but under .8mm you are under extruded.. if the wall is shorter or taller you need to fix the Z offset before the thickness can mean anything.

[Bikeracer2020]

By the time it gets about 2/3 of the way through the third side of the first line, it is pulling the first and second lines behind it like a dog following on a leash, No balling, no fuzzing, just won't stick..

Sounds very much like the nozzle is slightly too far from the bed.

Suggest.....Print a 50mm square just one layer thick and adjust the 'Z' offset in the slicer plus or minus 0.01mm, whichever brings the nozzle closer to the bed.
Remove print and see if each extruded line is stuck to the adjacent one, if not, then print again but alter the 'Z' offset by another 0.01mm or 0.02mm to lower the nozzle until all lines are stuck together.
If you start getting a rough sea effect the nozzle is too close.

230 nozzle temp seems a bit low. Perhaps increase the nozzle temp to mid way between recommended temps for your PETG.

[dbhosttexas]

I am trying 2 things right now which is raise the hotend temp up a bit, currently at 235, and bumping the z offset down by .01mm until I see the lines stuck together.Normal Z offset on this printer since day 1 has been -.65mm, I am currently at -.68mm with the nozzle at 235 and the bed at 85, and at least halfway through first layer I am seeing promising results. Cross my fingers here.

[dbhosttexas]

Just a real quick update here we have successfully made it through the first layer which is where it usually fails so I'm going to let it print for a while can I grab some lunch at my favorite place in my neighborhood and then check on the print when I get back 1 of 2 things will happen the first is it will be printing successfully and everything looks good or the second is I will come back to a big knot of screwed up print and Spewed out filament.

[dbhosttexas]

Came back to a bad print. Did more digging, someone on a different forum suggested washing the PEI with soap and water, thoroughly drying and wiping down with alcohol wipes between PLA and PETG which I am trying now. First layer finishing up but a good ways away from being confident here. At least there was nothing to draw my concern when I laid the first layer down, yet...