Loading

PETG Experience

Please Login to Comment

I've been using PETG for a little while, maybe a 1/4 kg. And I want to share how it's been. This is using the hatchbox white PETG.

The biggest difference to PLA is that the molten stuff is very sticky. This makes a couple things more difficult, which makes you really need to be on top of it.

The stickiness really affects overextrusion. If you have any extra plastic coming out, it will end up grabbing the nozzle, instead of just ending up as part of the print. The stuff that's on the nozzle will ball up, and eventually burn (which becomes brown in my nice white filament) and will eventually get deposited somewhere. This isn't those little warts that happens when your printer pauses, these are big blobs of plastic that end up causing big problems for future layers, which really ends up looking bad if you only look at the end.

So first, I really had to get the temp right, because there's no way the extruder will extrude consistently if the plastic isn't flowing smoothly. I did a bunch of test cylinders at different temps. Then I adjusted the flow % on a bunch of test cylinders, and ended up with 260C and 98% flow (this will be useless to your printer, probably). BTW, I upgraded to the micro swiss all metal hot end.

Then I hit my next snag, which is, even though my print bed leveling methods work fine for PLA, they are not close enough for the PETG. I was printing a big case, and the first layer is printed at 0.2mm and 110% flow, which should really help with adhesion. I could have dropped the flow rate, but what I did instead was just watch it print the first layer, where it really starts filling in the area. With my bed where I usually print it, it was making a bunch of blobs, so I turned each corner lower by 1/4 turn, and it smoothed out. I could have stopped, cleaned it up, and restarted, but I decided to cut the blobs off while it was printing, and the print turned out looking good, by the end.

So basically, it's harder (at least for me) to print than PLA. Nothing I did to make it work are things you wouldn't do for PLA, but instead of getting within 5%, I'd say you have to get within 1% for PETG.

I also removed my cooling fan, and I haven't reinstalled it. I'm sure I will get terrible performance with overhangs, but I haven't tried to print anything with a big gap yet.

hope you don't mind me joining in but i've had a lot of success with petg on my d-bot printer as well as my I3 after hours tweaking and many failures as mentioned i see a differance dependant on colour.
to get the first layer to stick any colour i use Kapton tape tried just about everything else kapton(polymide) it will stick the second big thing was the distance i have both printers set at 0.3 gap a thick playing card as it likes to be laid down almost air printed this avoids the furring and hotend picking up the stray bits also under extrude slightly .
speed slower than pla although this depend on the colour
white on my i3 print speed 25mm/s temp 240 my d-bot i can print at 35mm/s first layer 50% speed retraction 30mm/s 3mm
black i3 60mm/s temp 240
blue / yellow 30mm/s temp 240 for some reason my d-bot will print 10mm/s faster probably due to the hotend
bridging is almost impossible so use support which can be a pain to get off
hope this helps

Started this weekend with PETG, I just couldn't get right. Different temperatures, glass, standard bed nothing helped.
There where two problems, first it wouldn't stick when I started to print. Because of this some material was on place where it shouldn't be and it started to move and destroyed the print.
Also there was where a lot of wires when he moved to a new print location.

The first part I could solve with a simple method. I pre-heat my extruder for about 10 minutes at 245 degrees.
Before printing I extrude PETG until it stops filling up around the head. And a nice straight line of filament starts to come out.
When I than start the print job it comes there clean and nice out of the extruder.

The wiring on the objects was solved with the grounding mod. The temperature is now stable instead of the fluctuating temperature of sometimes more than 10 degrees.

I got verry nice results with PETG.

i find white PETG is harder to work with than black PETG.
eg:
white
print speed = 25
print temperature = 255
tip needs to be cleaned before and after any printing

black
print speed = 60
print temperature = 245
i find the tip not needing to be cleaned as much

settings i use for both
bottom layer speed = 10
bed temperature = 70
fan speed max = 25
retraction speed = 25
retraction amount = 2mm

notes:
i am using micro swiss hot end with D4S/MK7/MK8 extruder gear
software is Cura v14.12

I have 4 spools of MakerGeeks PETG that I really want to use - and I am still working through the details. I acutally got a few good prints early on, but now am just working back into using this stuff.

The sticky part is absolutely the hardest to work with - artifacts caused by the stickynes mimic over-extrusion, under-temp, and other types of failures. Through calibration prints I had found settings that made perfect calibration objects.. which then failed miserably on 3DBenchy (dramatic stringy globby mess!).

I do not have the all metal, so I dont want to push to 260 (though i have tried it) but i have also found that slower speed with lower temp seems to work pretty well - i was running 245, and got really smooth layers up until the sticky/globby part became an issue.

I have to return to calibration prints, try a few more adjustments and see if i can get a good overall. This plastic shows promise, but definitely requires some patience.

I had to turn off the fan, change the temp of the extruder to 245, the bed to 75, extrusion multiplier to 90%, retraction to 1.8 and retraction speed to 35, print speed to 40mm/s. I also have the micro swiss all metal hot end.

Bridging sucks with petg, I haven't figured out how to get it work well. Overhangs (up to 45 degrees) aren't too bad.

It's definitely harder to print than PLA.