Problems getting PETG to stick to the bed
I have an Original i3 MK2 that was upgraded from a MK1. For a few months after I upgraded it, which was in turn a few months after I bought the MK1 kit (i bought it right before the MK2 came out), I printed quite a bit and never had any adhesion problems with the PEI bed. At that time I graduated college and had to move a few times, so I didn't to use it, it sat up all that time. Finally, I bought place and had a room to set it up in and did. Also possibly relevant is I never did any humidity control with my filament, just left it sitting around in the boxes it came in (opened, as I used them all previously). I also upgraded my firmware to 3.1.0, and installed the latest drivers. Ok, back story done.
After I set it up, I couldn't get anything to stick to the bed, PLA or PETG. I tried cleaning it with isopropyl alcohol, rubbing it with a kitchen sponge with the scrubby side (in circles), and glue stick. No luck. So, finally, I thought maybe my filament was bad, and ordered a new spool, with which I had the exact same problem. I have been reading posts, articles, etc for weeks and trying all the stuff I found.
I also had been having issues with clicking from the extruder. I had been slicing with Prusa Control, and finally decided to switch to Slic3r and increase the temperature. I had been using the prusa default for PLA and PETG of 210/55 and 240/85 (I think those were the temps). I increased my PLA temp to 240 and bam, all of a sudden I was able to print again, no clicking, and it was sticking. Not perfect, but it seemed pretty close. So, after a few PLA successes, I decided to try PETG again. I bumped the bed to 90 and the hotend to 250 and was able to print a phone stand that didn't have a lot of surface area on the first layer (prints on its side). After printing out 3 of them that came out pretty good, I wanted to print out something that did have a lot of first layer bed contact. Well, it didn't go very well at all. I tried all 3 spools of PETG that I have, including the black that I used previously for the phone stand. I've tried multiple times and had zero success.
The next thing I'm going to do is clean all of the glue off the bed, and try it without glue, hoping that maybe it is actually interfering? Any advice would be hugely appreciated. I am just about ready to give up and throw the thing out. Or maybe dump it on craigslist.
One of the attached images in the black phone stand that I had reasonable success with, and the other is the large bed contact failed print.
PS, I also bought one of those food dehydrators and modified it so I can put a couple of spools of filament in there, and cooked all my spools for 4 or so hours, and I have some airtight containers with silica gel packets (15-20) in each, so they should be staying nice and dry now.
Re: Problems getting PETG to stick to the bed
I decided to reslice the same file and use PLA this time, and here is a pic of it printing the first layer. Much better, and getting good bed adhesion, though the top right section does look a little... off. At least it is sticking.
Re: Problems getting PETG to stick to the bed
A couple of things to note:
1) When you change temps of bed an nozzle the "Live Z" can change. You will need to recalibrate it for the new filament.
2) PETG sticks like CRAZY to PEI. You need a little barrier there to prevent it from fuzing permanently to the PEI (and destroying the PEI when you pull it off). I have tried glue stick and windex. Windex works much better in my opinion. Clean the bed really well - acetone and IPA (pure). Then a brief cleaning with windex (blue glass cleaner). PETG sticks well but not too much.
Good luck.
Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss. If you solve your problem, please post the solution…
Re: Problems getting PETG to stick to the bed
A couple of things to note:
1) When you change temps of bed an nozzle the "Live Z" can change. You will need to recalibrate it for the new filament.
2) PETG sticks like CRAZY to PEI. You need a little barrier there to prevent it from fuzing permanently to the PEI (and destroying the PEI when you pull it off). I have tried glue stick and windex. Windex works much better in my opinion. Clean the bed really well - acetone and IPA (pure). Then a brief cleaning with windex (blue glass cleaner). PETG sticks well but not too much.
Good luck.
Thanks for the information Aaron. I have since cleaned the bed really well and tried directly on the PEI and still had problems with it sticking, and it seems to be in a certain area where the problem starts. I am thinking I might have a problem with my PEI sheet. I will try adjusting the "live z" as you suggest and see if that helps.
Also, on the subject of the windex as a release aid (assuming I can ever get it to stick so that I need a release aid in the first place), do you just spray it on, or wipe it on? Let it dry first?
Re: Problems getting PETG to stick to the bed
Aaron,
Thanks for the help, it seems further adjusting the "live z" was the missing piece of the puzzle. I had no idea that it would need to change, I just thought it was a fixed parameter of the printer itself.
On the subject of the adjustment, is it most closely associated with the temperature or the filament? IE can I figure out the value for a particular printing temperature and use it for any filament printed at that temperature, or will I also need to do it for each filament/temp combination?
The attached picture is still rough, but it stuck. I also adjusted the z while printing the left half and the right half looks much better too!
Re: Problems getting PETG to stick to the bed
On the subject of the adjustment, is it most closely associated with the temperature or the filament? IE can I figure out the value for a particular printing temperature and use it for any filament printed at that temperature, or will I also need to do it for each filament/temp combination?
Glad you got it working.
I think the Live Z is mostly tied to the bed temperature (as the bed expands, it buckles a bit) and the viscosity of the filament. But I have not done a careful study on that. I figure out the correct Live Z for each new filament type. PLA, PETG, PC, etc. They are never too far off, but they do change.
That first layer is so important it is worth your time.
Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss. If you solve your problem, please post the solution…
Re: Problems getting PETG to stick to the bed
[...]
Thanks for the help, it seems further adjusting the "live z" was the missing piece of the puzzle. I had no idea that it would need to change, I just thought it was a fixed parameter of the printer itself.
[...]
The PINDA is sensitive to heat. If the heatbed is not at the exact same heat, the value reported by it will change. That's why the PINDA2 in the mk3 has a temperature sensor embedded inside, to improve it.
Re: Problems getting PETG to stick to the bed
[...]
Thanks for the help, it seems further adjusting the "live z" was the missing piece of the puzzle. I had no idea that it would need to change, I just thought it was a fixed parameter of the printer itself.
[...]
The PINDA is sensitive to heat. If the heatbed is not at the exact same heat, the value reported by it will change. That's why the PINDA2 in the mk3 has a temperature sensor embedded inside, to improve it.
Durand.r is correct. However there is also movement.
I have changed the gcode at the beginning of the print to always do the pre-print z-calibration (where the PINDA is used) at 170C, and then to change to the filament settings. I also park the head at a largish Z value while heating so the PINDA temperature is rather repeatable. I still have some differences between PLA and PETG in the Live Z. Wish I could just buy a magnetic bed and PINDA2 rather than the full upgrade kit.
Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss. If you solve your problem, please post the solution…
Re: Problems getting PETG to stick to the bed
I know this is a long delayed reply, but I finally figured it out. I had damaged my nozzle tip. Not going to go into details to protect the guilty (myself, lol). I replaced the tip and was able to calibrate it to a certain z-live adjust and now I am printing perfectly with both PLA and PETG.
Thanks for the help.
Re: Problems getting PETG to stick to the bed
For me the key was:
- raise the first layer height to 0.3 mm
- lower the first layer speed to 10 mm/s
Actually for all materials lowering the 1st layer speed works better; this should be the Slicer default IMHO...
Re: Problems getting PETG to stick to the bed
And clean the bed with Acetone!
I thought my print bed was clean; prints did not stick 100%; after cleaning with Acetone (not nail polish cleaner...) and changing nothing else, it stuck like... well it stuck 😉