PETG

Someone have advices for Printing with PETG?
Temp, Speed....compared with PLA
Thanks

I found PETG a fair bit more touchy. My hotbed is PEI and I could not get any stick at first, then I upped the temps a fair bit for my first layer. Then I had trouble getting it off!!

So here is what I found worked for me after I got it all working ok:

Hot End temp first layer 235c
Hot End temp 220c
bed temp first 5 layers 80c
bed temp after 65c

First layer print speed 15mms
print speed 35mms
infill speed 35mms
travel speed 70mms

fan speed 40%

I have not used PLA in many months I got away from it and was doing ABS for quite a while.

as I recall I was around these settings:

bed 60c
hot end 190c ish
fan 100%

speed 60-80mms

oh and one more thing, I found I had to back off my first layer more, with PLA and ABS I got used to squishing it into the plate on my first layer. With PETG I found I had to reduce that squish ALOT!!
I am almost just laying the first layer down now, I would say my nozzle is .29mm from the bed and laying down a .3mm first layer

right now I am struggling with over extrusion causing a buildup on my nozzle, but if I reduce the extrusion multiplier I get gaps in walls...

Edited 3 time(s). Last edit at 01/09/2018 02:47PM by JustSumGuy.

Going to steal this topic but,

Is it normal that I cannot print Esun white petg over 27mm, after that it just sticks to nozzle.

Temps are something like 240c or 245c and hotbed is 60c

Filament rolling off the bed is a sign for a wrong nozzle height. As mentioned above, too much squish will dip the nozzle in the filament and drag it away.
Babystep the nozzle up in 0.02mm increments until you find the sweet spot.

Edited 1 time(s). Last edit at 02/17/2018 02:49AM by o_lampe.

First do a 'Vase mode' test to see if extrusion is ok. 'Extrusion Multiplier' setting is completely different compared to PLA or ABS.
And indeed squeezing the first layer PETG onto the bed is not a good idea at all..! It should be gently 'rolled' on the bed(like o_lampe mentioned higher up). iow the nozzle should be set higher compared with PLA or ABS. I first thought too that would result in not sticking to the bed, but no worries it works.
Lower printspeed. Print temperature should go up. Bed temp 75/80°C. For PETG and I always use 3D-Lac.
First layer NO partscooling at all. For the rest as little parts cooling as possible. You should find yourself a good compromise. The higher parts cooling the smoother/nicer the perimeters. On the other hand lowering partscooling during printing should result in stronger parts. Mine is set at 25%
Set retraction higher if stringing occurs, it surely will. Mine is set at 1.5mm(direct drive).

Do not test on a very small part, it will not work. That is mistake most print-nerds do. Small parts need to be printer with slightly other settings.

Those are good points all, but mine first layer is perfect (I think), maybe too good what comes to getting the parts out of the bed...

My problem is that in next layers when the speed should rise, I can´t get it to stick to previous layers and its sticking on nozzle. I´m doing first layer at 20mm/s and next layers absolutly maximum is 27mm/s...

There´s no problem with stringing and oozing... Retraction settings are now perfect at 2mm and 20mm/s...

Very strange story. I'm busy printing a PETG part this very moment, no problems at all.
Nozzle0.4, temp75/245°C Speed:55mm/s Layers0.2mm retraction:1.5mm 1stLayer no cooling other layers:minimum cooling Bed:3DLac. ExtrMult:0.92
I use silicone socks to 'cover' the heaterblock. Those silicone socks, I wouldn't print without them at all.

What's the nozzle's diameter you're using and what is the height of the layers.

I´m using 0.4mm nozzle. Layer height is usually 0.2mm or 0.3mm. I´m in process to order newer type of hotend-block to be able to use silicon socks.

Extruder is working and wont click at all, I too use a little underextrusion of 0.96 to 0.98. I don´t use cooling at all, ´cause it destroys last rips of layer adhesion I have...

Bridging is almost perfect with my settings and no stringing or oozing at all, could it be just cold extrusion?

I'd say start using socks(on the printer that is..) It's a BIG difference, you'll see...

You also mentioned filament sticking to the nozzle. Check that nozzle, clean it. Or maybe there a small burr somewhere in/or at the nozzle... somewhere...
Manual feeding the nozzle should always result in dropping the filament straight down. If not the nozzle is not clean or not free of burrs.

Maybe there something in my nozzle, if I extrude in the air I got loops. Start of the filament stucks to nozzle and rest of extrude go straight down making loops...

Edited 1 time(s). Last edit at 02/20/2018 01:10PM by kapperi.

If you have loops during extruding in the air, there's something in the way. Be it a particle or burrs, you must remove it.

Theres definetly something wrong with my nozzle, waiting packet from e3d with updated block and a couple of new nozzles.

I started to print with pla and layerbond is way better than with petg. Only thing is that I have to keep 240c with pla too. Its very odd pla roll or i have to get thermoter to measure real temps of nozzle if its somehow lies too much...

Hmm, something wrong with my petg roll too? I think that maybe I printed with too cold?

Also I have Tevo titan type extruder and had to change bigger stepper to it, now its working right. I have to test petg again with higher temp...

Heat up the nozzle to the usual temp and push some filament from the outside against the nozzle. It should melt nice and easy. If not, the temp sensor is off, or the hotend has too good contact with the heatsink.

Ok, still waiting for update to right block to get socks on.

Still without the socks on, I have managed to get this printing ok. I think that it was compination of too cold and, what was supricing that lowering acceleration makes a huge difference with peth, for me atleast.

Bigger motor too in extruder helped a lot.

Now I´m printing 50mm/s and 260C, at 0.3 layerheight. Accelerations are 600mm/s2

Quote
kapperi
Also I have Tevo titan type extruder and had to change bigger stepper to it, now its working right. I have to test petg again with higher temp...

I'm looking at using two Tevo titan extruders for my IDEX style 3d printer design. Do you have any specs for the stepper you needed to get the Tevo titan to work correctly, and on the one that didn't have enough power?

It might save me from making the same mistake.

I'd appreciate the input!

Quote
kapperi
Those are good points all, but mine first layer is perfect (I think), maybe too good what comes to getting the parts out of the bed...

My problem is that in next layers when the speed should rise, I can´t get it to stick to previous layers and its sticking on nozzle. I´m doing first layer at 20mm/s and next layers absolutly maximum is 27mm/s...

There´s no problem with stringing and oozing... Retraction settings are now perfect at 2mm and 20mm/s...

Whats your extrusion width? you may be able to go faster with a wider extrusion as it forces the plastic to squish against the lower layer before the bead expands sideways (I print at .52 width with my .4 nozzel on certain models)

Edited 1 time(s). Last edit at 04/29/2018 07:39PM by DaGameFace.