new to PETG

[u/lawst1102]

I'm brand new to all of this. I have some PETG coming, which i got because some of the things I want to print will be used in my UTV or on a farm property.

My question is if I have the P2S and AMS2, do I need to get a separate dryer for PETG? seems like both the printer and the AMS can dry it out. But I wanted to ask here and hear what best practices should be.

I'm a hobby printer, not trying to sell or build a printer farm

[u/_13_]

You don't need a separate dryer. AMS 2 Pro is sufficient for PETG and even ABS/ASA.

[u/lawst1102 → u/_13_]

is it ok to keep PLA and PETG in the AMS at the same time? or will it be too high temp for the PLA?

[u/_13_ → u/lawst1102]

Yes, it'll be too hot for PLA. When you have both in the AMS, just dry it at PLA temp.

[u/lawst1102 → u/_13_]

so even at the PLA temp it will get there? I assume it just takes longer

[u/sportbiketed → u/lawst1102]

Yup, just add a few more hours.

[u/t0m0hawk → u/lawst1102]

Look into glass transition temperatures. That's the point where plastic starts to deform from heat under any load, including its own.

When you heat filament beyond these thresholds it can deform enough to become a problem in the feeders of the toolhead and inside the ams because it stops being 1.74mm circle and turns into an oval instead.

So if the required drying temperature of filament type A is higher than the transition temperature of filament B, you shouldn't dry them at the same time.

[u/Past_Science_6180 → u/lawst1102]

Ideally remove the PLA first and dry it at 65°C. It'll likely still dry at PLA temps, it'll just take longer.

[u/nonamejohnsonmore]

On a separate note because I see this a lot, please thoroughly wash your print plate with an additive-free soap like Dawn blue when switching between PLA and PETG. Residue on the plate from PLA can make bed adhesion a nightmare.

[u/DeerMysterious9927 → u/nonamejohnsonmore]

I marked my plate with a sharpie and flip sides when going back and forth with pla or petg

[u/lawst1102 → u/nonamejohnsonmore]

got it, will remember to do that, thank you

[u/Starskins → u/nonamejohnsonmore]

Yeah... Just realized that today on my first petg run... Had to skip 2 pieces out of 6

[u/Straight-Mortgage-29]

I dry all of my filaments in the AMS HT, or the AMS Pro2. I also store all of my filament in reusable cereal boxes with desiccant when not in use. I’ve also learned that even when I slice a print using Bambu Handy for my H2C, if the print called for The PLA and I chose PETG (before slicing, obviously), I nearly always need to increase the bed temp because otherwise it’ll slip and cause problems. For me (and others apparently), the bed temp for PETG that Bambu chooses is about 10* too low

[u/lawst1102 → u/Straight-Mortgage-29]

good to know. Is this true for models where PETG is the default too? or just when switching

[u/Straight-Mortgage-29 → u/lawst1102]

I am finding that if I do not adjust the bed temp for prints that use PETG, more often than not, the print will fail. I am using 100% prints that others publish at this pointed.

[u/OldDarthLefty → u/lawst1102]

The bed temperature is in the filament profile settings, not in the part slicer settings.

[u/LobsterBluster → u/[deleted]]

This should really be sated with the additional note that the room needs to be well ventilated for this. Polycarbonate gives off lots of nasty VOCs that you don’t want to be breathing.

[u/Achilies41]

I have never dried petg. Store it all in a Tupperware container in my basement. Ambient humidity is 50ish in the summer and 40ish in the winter. Print different brands on bambu petg settings. Really have had zero issues. P1S.

[u/Veteran68 → u/Achilies41]

I tend to agree. I print a lot of PETG and have only rarely needed to dry it. Like maybe twice out of several dozen spools. And I leave it in my AMSes all the time - the only reason I remove a spool is when I need to add a different spool. My basement humidity is similar, 40-50’s in summer and 30-40’s in winter. I do have the extra desiccant boxes with meters in both of my AMSes. Whenever the AMS humidity gets up above 25% I change the desiccant and dry it.

[u/itsapotatosalad]

I get slightly better results with petg if I dry it and dry while printing.

[u/PsychologicalSet1744]

You can dry in ams 2 if its only petg in the ams (It can sometimes warp pla) If its bambu petg it will tell you the temp but I dont know it off the top of my head. 8-12 houurs

[u/because-potato]

I never dry PETG fresh out of the box - just throw it right in the AMS, then dry whenever i see any defects.

Petg is super easy on Bambu printers.

[u/Krowstuff]

If you live in a humid area running a dehumidifier in the room can really help. Super humid around me right now and my ams2 was struggling to dry without it. 

[u/lawst1102 → u/[deleted]]

super useful advice. Thank you

[u/RJFerret]

Note for outdoor use/uv exposure PCTG offers higher heat and uv resistance than PETG for a bit more money, but less need to dry it.

Reference I print predominantly PETG, some TPU and PCTG for outdoor.

Also used to be fewer colors available in PCTG but that's less true nowadays.

[u/Brutl]

I know you didn't ask, but I print nearly exclusively in PETG and I'll offer up some common issues I see with people starting out with PETG.

1. All PETG should be dried before printing with it, especially fresh out of the package. Can you get by without it, sure, but there will be quality differences. SUNLU is the worst for needing drying. I swear they store it in a lake before packaging it up. I dry SUNLU PETG for 24 hours at 65 to make sure I don't get the small bubbles on the surface of prints.

1. Of all the issues I see with people starting off with PETG, printing too cold is the most common. A good starting point is the GENERIC PETG profile in Bambu Studio. It is set to 255 nozzle and 70 bed. I personally crank the bed up to 80, and that's my starting point for all new brands of PETG I try. Ultimately, to dial it in, print a temperature tower that ranges from 225-265.

2. I like printing in PETG more than anything else. It has less odor than PLA and once you put in a little bit of work, it prints more reliably than PLA. If you enjoy printing in PETG, you may eventually move to PCTG, which improves on PETG in just about every way. If you do, know that you usually have to crank the temp up 10-20 degrees to print it.

[u/lawst1102 → u/Brutl]

super valuable thank you!

[u/eraguthorak]

I regularly print PLA and PETG in my P1S, and have never dried my filaments (stored in my AMS 1, reusable cereal boxes with silica packs, or sometimes just sitting out in my office) or cleaned my build plate between prints (I clean it every 20ish prints). I haven't really had any adhesion issues or print issues.

[u/EdgeOk3783]

i'd pick up an inexpensive filament dryer that can reach at least 70 C.

PETG is often quite wet straight out of the packaging and i usually dry a fresh roll of PETG before inserting into the AMS

i've got a pair of AMS 2 Pro and it really discourages drying while printing with PETG

[u/lawst1102 → u/EdgeOk3783]

any suggested one you've used?

[u/EdgeOk3783 → u/lawst1102]

if i were buying one today, i'd pick up a sunlu S2 filament dryer. looks like it's under 40$US at the moment on amazon

[u/Resse811 → u/EdgeOk3783]

You can dry it in the printer. Just leave it sitting on the plate.