PETG With Textured Sheet
I've been printing nearly exclusively with PETG and the textured sheet on my MK3 for the last four years. Apart from having to do an occasional first layer calibration and some slight stringing with some filaments I've had very few problems. I recently did the MK3.9 upgrade and PETG on the textured sheet has worked just as well (possibly even a little better) as before.
So, when I got the XL the first thing I tried was PETG on the textured sheet. It barely stuck at all. I initially did an alcohol cleaning as I always do with a fresh sheet. But, I decided to do a soap and water pass followed by alcohol. Maybe it was slightly better but it was clearly coming up in corners and tight details. The layer height looked correct (based on what I'm used to on the MK3). I did try slightly lowering the Z height but when it did stick it clearly showed signs of distorting the first layer when it went over it on the second layer.
The satin sheet prints just fine with PETG except for some distortion on corners. I never see this on my MK3 with the textured sheet so I'm assuming this is a side effect of using the satin sheet. (Which is why I'd like to print with the textured sheet in the first place.)
I'm kind of out of ideas. I was thinking about attempting to print with the MK3 sheet on the XL just as a test.
I'm using a 0.4mm ObXidian nozzle on both the 3.9 and XL (I originally started trying to print with the standard brass nozzle with the same issue). I'm testing with the exact same spool of filament on both as well (Hatchbox Natural but I also tried Prusament Galaxy Black once).
Any suggestions would be greatly appreciated. Thanks!
RE:
I was just about to post about PETG--I'm on MK3.5 but found my way to this post.
I just upgraded from MK3S to 3.5 (via 3S+. An ordeal in itself I'll post separately). I broke/wasn't able to print some parts before disassembly. Got to the end and was trying to print the missing/replacement PETG parts and ran into loads of trouble. I replaced the hot end I broke with this and am using the silicone sleeve--which was apparently necessary to declare when I calibrated. I'm using 0.4 hardened steel nozzle.
Findings:
Before disassembly, I was printing PETG but my hot end was leaking. Parts were sticking too much to the smooth sheet and then I read somewhere that PETG will ruin these, better on textured which I'm assuming you know.
At 0.1 Fast and 0.1 Structural on textured sheet, part slipped, got really gloopy and pulled away. I tried reducing the speed on the solids and it still pulled away mostly in layer 2. I even tried processing the part on different parts of the textured bed. No luck.
0.2 Fast, better but gloopy and pulled away.
0.2 Structural and I have a part. I'm going to continue with this setting for my PETG parts. when I go back to PLA which is what I normally use, I'll try the other settings.
RE: PETG With Textured Sheet
New Textured build plates tend to have slippery surfaces.
I Find that If I wash the build plate vigorously with Hot Water and Dish soap, using a new kitchen sponge, rinse well with Hot water, and dry immediately with plain paper towels, the build plate offers much better adhesion (Keep your fingers off the build plate surface
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: PETG With Textured Sheet
Interesting. Are you able to print 0.1 layer thickness? fast? I don't think my problem is a sheet problem.
RE: PETG With Textured Sheet
to be honest I Rarely do 0.1mm first layer especially on textured sheets, if there are no features in lower layers I use o.2 or o.3 first layer then go to a lower layer height afterwards.
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: PETG With Textured Sheet
Even on my Mk2.5s which was always perfect, 0.1mm first layer + PETG always gave me problems. The lifting with the smooth sheet might be a temperature issue, the room my XL sits in gets really warm when the sun is out and then I have zero issues. Until I have an enclosure I just don't print PETG when it's colder than 30°C.
There are alternative build plates available at aliexpress now, the gold ones used to work a bit better for me than the originals (but won't survive as long). Might be worth a try.
RE: PETG With Textured Sheet
PETG on textured works super on MK3s.. but if I have small features I don’t hesitate to use some alternative “stickiness” like glue stick.
RE: PETG With Textured Sheet
I'm on record for not being impressed with the "always perfect" first layer on anything but PLA on smooth (which I never use).
I now routinely put a thin layer of Layerneer on the satin and textured sheets of my XL and Mk4'sx and that--plus some manual adjustment of life Z by a bit—seems to work most of the time.
RE: PETG With Textured Sheet
I actually now **always** coat my textured with a thin layer of glue stick. I like the finish on my parts.. and I can use PLA with not having to change the sheet setting in the LCD.. (which I forget to do and have ruined a sheet or two. Mk3s). Just easier in the long run. I clean and change coating about once every 3-5 days.
RE: PETG With Textured Sheet
Well, I decided to try and crank up the heat bed temps for the first layer and realized the settings for "Generic PETG" on the XL are different than the "Generic PETG" settings on the MK3.9 for some reason (at least on mine). The MK3.9 has the heat bed temps at 85C for the first layer where the XL has it at 80C. The nozzle temp is also different at 240C for the MK3.9 and 230C for the XL. I'm not sure if this is just my install or are the same filament present different for different printers?
Anyway, I took the settings from the MK3.9 preset and the first layer calibration test I'm printing now is working MUCH better. Still not perfect but it made it through the whole test without me having to stop it because it was accumulating filament on the nozzle. It's certainly usable now.
RE: PETG With Textured Sheet
I don't think you'll get exact temps across different machines.. I think some early issues with the XL were with different thermistors in the hot end so some were much different temps than being displayed on the control screen. So not only might the profiles be different, but I doubt 230 on one hotend is exactly 230 on the other, nor are both likely exactly to be 230.. so that's where a temp tower might be good, or even some way to test the calibration between them.. maybe an infra-red gun on the hot-end. Same scenario for the bed because the temp sensors might be in different spots; or the sheets are slightly different, etc. I think Bambu uses about 30C for PLA where I'm using about 65.. So each printer needs to be tuned since they are different designs.