I have read a number of postings on this site regarding tricks to get decent results from PETG. None of them work.
Early attempts found all extruded material not adhering at all to the print plate, but rather blobbing up on the end of the print nozzle.
I have tried various nozzle temps from 225 to 235 and raising the zero clearance to 1.5, and bed temps from 70 to 85, as well as stick glue to help adhesion, all with no usable prints.
The discussion of zero clearance requires some clarification: Before each attempt to print I perform a calibration, using twenty-five points to establish a level print bed, and then use the calibration and to establish nozzle height. For PETG, I am told that the card must be able to slide freely in both directions but with some contact with the nozzle. My question is, "does this establish the so called zero clearance height of .15 required for PETG, or must one also set a .15 ZC setting when starting the print? I’ve tried both ways and still can’t get a working print.
Sound like you’ve got your nozzle height too high.
Start with the card barely being touched and try printing from there. Then look at how the first layer is going down (lots of photos of that in other threads) Then adjust z-offset.
Also your nozzle temp sounds low for PETG. All my PETG prints somewhere between 240 and 260. What does the manufacturer say?
I do use gluestick for a little extra margin of error, but don’t necessarily feel I have to if everything is set right.
Have you tried printing a temp tower?
Ive been fiddle fucking with petg for the past few days and im so tired of fighting with it.
i get it to go smoothe then it starts making little crumbs and stuff which i think is probably moisture, but i dehydrated a spool and it had no effect
i am officially on petg strike until i get a spool in from matterhackers to try again.
you do have to be real close to the sheet tho. i had it tuned in pretty good but today i had an issue and had to take the hotend out and i am so sick of fiddling with it so i change back to pla for now.
I was using a feeler gauge to get .05 space instead of .1, but its all kind of moot when everything is based on “feel”
I also thought the nozzle might be too high, but when I lower it, the print doesn’t adhere, and simply blobs up on the print nozzle.
If I understand what you second paragraph is saying, when I calibrate the bed, the height of the nozzle (just touching the card) is where I should leave my zero clearance, and adjust only if that isn’t working. Right?
I have only tried temps between 225 and 235. Haven’t tried anything close to 240 to 260. Perhaps I should try that.
I use glue stick as well, but notice absolutely no difference in adherence, which in all of my attempts has been non-existent.
I’ll try your suggestions, hoping I am interpreting you correctly.
@wilburg You are correct.
If you want to share a picture of your first layer we can help analyze.
You might have to raise but that’s where to start;
I’ve found with pla I needed .05 offset, petg .1 to .15 and tpu 0.
Retraction is important for stringing but let’s get you adhering first.
If you want to wash off your bed with water and then wipe down with rubbing/isopropyl alcohol and then apply glue stick it wouldn’t hurt. I use the elmer glue stick that is purple when wet. I apply a thin layer in barely overlapping strokes and by the time the bed is heated up its dry. Other people do a wipe down or smear it around and try to get it thinner. I haven’t found a need. It usually lasts for at least 5 or 6 prints. Probably could push it longer.
Definitely check recommended printing temp, both nozzle and bed. Usually is on the spool.
-S
@MooseJuice Definitely got to get it figured out. When it’s working great it’s awesome to make stuff out of. A lot more strength and flexibility than pla.
I prefer a temp tower that goes up: SmartTempTower_A350_PETG_220to265.gcode (3.8 MB)
On some filaments when you get to the cooler temps you have problems. This way if you get to the point where it’s not adhering it just starts doing the spaghetti thing.
There’s also a good chance it has some moisture in it… I’d say 90% of the spools I open are wet. I started with cheap dehydrator which was fine but wasnt getting hot enough for some materials and ended up buying a printdry system actually, never thought id do that.
Its a real problem.
I enjoyed using the snapmaker petg from their store (blue) which i believe is a blind labeled eSun product now that they have a new supplier to give further credence to your experience with the eSun.
its the only petg ive used that i can say was satisfactory so far.
i have some matterhackers coming and will likely sing its praises to you guys when i receive it.
I’ve used both Prusament and Filamentone and found both to be very good quality. Don’t know if PETG is more susceptible to variance in diameter but both of those brands have very strict tolerances.
Does it extrude fine when loading? Do you get a nice thin string from the nozzle?
I haven’t had the problem with moisture that @MooseJuice has had. But I’m in southern California. Most of the year it might be just as effective to leave the filament sitting out as in a dehydrator. I do still keep my rolls in sealed containers with lots of desiccant. I did have problems with SM black and moisture - but then most people have.
Its almost to the point i wont even use a spool unless i dehydrate it first when they are brand new. straight out of the vacuum sealed bag.
I give some slack to the matterhackers material, but even some of them need it.
now, often times its very minimal, but you can tell… a little pop here or a little crumb there… PLA usually it doesnt make a huge difference unless you have a BIG FLAT surface, you’ll see it. on petg it ends up causing alot of problems for me personally tho. blobs and zits turn into a nozzle coating then the part gets stuck to the nozzle even sometimes.
I were also at wits end with PETG and tried many things. One of the biggest problems is to get the first layer to adhere. After a LOT of experimentation, I found the following to work for me.
I also heat up the heatbed manually to 85deg C before I start the print for a few minutes before I hit start as I found that the heat distribution is not even and the outsides seems to not be at the same temp as the center. That gives the heat a chance to spread evenly.
You may have to tweak your retraction parameters for your particular filament to prevent stringing. If you have small tall objects, add a raft or at least a brim to it and the Z hop is important!
I hope it helps as I was about to dump my PETG, but I needed a springy material for my print.
My material is from CRON and did not dry it out beforehand.
