Problems with PTEG
New to 3D printing and using PTEG Filament as PRUSA recommended this on live chat when purchasing the printer.
we are finding that the filament isn’t sticking to the heat bed or after a few layers the model is sticking to the nozzle.
it’s working fine with the PLA filament.
as far as we can tell we are picking the right selection on the control before printing so any tips would be greatly appreciated
RE:
Are you using Prusa PEI sheet on Prusa MK3? or other. PETG prints as easily as PLA. If you are printing PETG, you can use a smooth, satin or rough(textured) sheet. On the smooth sheet, PETG will grip too well and you can damage your smooth sheet, so use a thin glue stick layer so the part will bond to the glue and you can release it later. If the PETG filament is not sticking, possible causes are:
1. Your Z is not close enough to the sheet (note if you get a Prusa Rough and Smooth sheet, they require different Z settings) .. if you are new.. this is likely your issue.. Send a really close up picture of your first layer calibration with PETG.
2. Your bed temp is too low.. 80-85F should be good
3. Your filament temp is too low, usually not a problem as I use 220F on most PETG
4. Your sheet is dirty, clean with dish soap and hot water.. You can also use IPA if you've gotten something else on it.
It seems like you might have a Prusa printer.. if so, I'd recommend getting a second PEI sheet.. either the satin or rough.. (I haven't used satin). You will need to store a new Z for that sheet (in LCD menu on printer) and you need to remember to select the proper sheet when you change it. Otherwise you might bury your nozzle in your smooth bed.
If you only do PETG occasionally, use glue stick on the smooth sheet until you get used to it. I love PETG and prefer it most times over PLA. PETG will fuse a bit easier in layers which is good & bad. If you are doing print in place, you might need a cooler temp or the fan on more so your moving parts don't fuse.
Please run the built in first layer Z offset calibration and show us the result *on the print sheet*
A picture of the bottom of one of your failed prints might be intructive too.
Cheerio,
RE: Problems with PTEG
Hi we have a Pruca mini + with a smooth plate.
I have ordered some glue to see if that helps.
it’s my sons and he is out but I will send pics when he is here
thanks for your help
RE:
Not sure where you are located but I just go to the Dollar Store/Walmart, some high-volume discount store and get a 40g glue stick.. I use Elmer's, all purpose, washable.. Doesn't need to be special. Likely a different brand stick came with your mini.. At least one came with my MK3+ kit last year. Likely it is your Z height.. lots of info here on setting that right.. Do a search for "life adjust Z - my way" and you'll see a whole thread on it and a model of squares you can download to do a "live z" adjustment.
Remember that the purpose of glue is to REDUCE adhesion with materials like PETG that might otherwise stick too firmly.
Show us that first layer.
Cheerio,
RE:
I found that the concept that glue ‘reduces’ adhesion caused me some confusion, in certain situations when starting out. Rather, it provides a different surface for the filament to bond with. Sometimes it provides a stronger bonding surface between some PEI sheets and some filaments. Thus when you use glue stick with PETG, the PETG binds to the glue’s top surface (ensure the glue is fully dry before starting the print). Releasing the part, causes the bottom layer of the glue to pull away from the bed. Yes, the PETG-glue bond might be slightly less than PETG-smooth surface bond, but this is not true for all filaments on different sheets. The bond of the bottom layer of the glue to the PEI smooth sheet is certainly less than the bond between the smooth sheet and PETG, thus saving your smooth sheet. When I’m using the PRUSA rough PEI sheet, it provides less bond to PETG (and PLA) and so you can use PETG directly; but the rough sheet has too low a bond for PLA. However, if you are using the rough sheet and suddenly want to print one PLA part, I’ve used glue stick on the rough sheet. Glue provides a stronger bonding surface to PLA than a rough PEI sheet so the PLA sticks better to the glue better than it would on the rough sheet directly. You can use this technique to get some different texture on the bottom layer of your PLA model, as it will still pick up a bit of the texture of the rough PEI sheet, or just to save you from changing your PEI sheet settings in the LCD menu (which i sometimes forget to reset when switching sheets back)
When i was printing small PLA models, with a small surface area, I found that glue stick on the smooth PEI sheet gave more reliable results. There is a bit of an art to getting a nice thin glue-stick coating. Now this might have been due to some flaws on my smooth sheet as it wears. But something to have in your ‘tool-kit’ of techniques.
RE: Problems with PTEG
I use the MINI Double-sided Textured PEI Powder-coated Spring Steel Sheet,
which works perfectly with the Prusament PETG.