PETG - that doesnt want to not warp!

Hi Guys, i thought i would ask the internet after googling must of been 1000 times about this issue. i am having real issues with PETG, PLA prints a dream, but i just cannot get PETG to stick to the Bed!!!! i have tried every bed temp from 40-110^C and extrusion from 220-260. adjusted the bed height, i am using a microporus bed and i have tried plain glass as well. tried it well squished, not well squished into the bed. i just cannot get the stuff to adhere correctly!

i have ordered 3 different rolls of PETG,dried 2 of them out just incase it was damp, none seem to work. must of wasted 500g of filament trying to fix this issue so far. no luck...

anyone managed to have the same issue. i am printing on a Ender 3 PRO (got her for under £65 ;);)) tried that magnetic bed thing with no luck either.

PLA works a storm. i can print anything with super results, but its just this PETG (i really want to use it for its flexibility and strength) that is doing my head in!?

any advice from the wise?

Thanks

UPDATE:So i managed to get it to stick. i really needed to squish it into the bed and heat it up to 90+ Degrees to adhere and stop warping. but my issue now is i have destroyed a glass bed as it completely locked onto it!if i use hairspray it doesnt adhere at all. if i raise the Z offset by 0.1mm it doesnt stick at all and gloops to the nozzle. i think i am going to give up on PETG to avoid destroying any more beds.it seems i cannot get the right mix. PLA prints a dream. looks like ill be trying ABS instead and see what results i get.

Hi Sorry to take so long to reply!! Glass beds certainly give an ideal flat surface to print on but can be difficult to remove because of this I have been using a thin 1mm sheet of Tufnol (Garolite in the USA) with the surface shine rubbed of wih 240 grit sandpaper and clamped to the glass bed stuck models can be easily removed by just flexing the Tufnol sheet. Most filament materials stick readily to Tufnol with the help of a liitle adhesive. for PLA and PET I use PVA glue stick, for ABS ABS milk and for Nylon just clean the Tufnol with Acetone. I hope this helps

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Originally Posted by Gambo

Hi Sorry to take so long to reply!! Glass beds certainly give an ideal flat surface to print on but can be difficult to remove because of this I have been using a thin 1mm sheet of Tufnol (Garolite in the USA) with the surface shine rubbed of wih 240 grit sandpaper and clamped to the glass bed stuck models can be easily removed by just flexing the Tufnol sheet. Most filament materials stick readily to Tufnol with the help of a liitle adhesive. for PLA and PET I use PVA glue stick, for ABS ABS milk and for Nylon just clean the Tufnol with Acetone. I hope this helps

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Thanks for the advice. i managed to get some good results for some prints by heating the bed to 110 Deg first layer then 95 for the rest of the print. this only works on big first layer movements, small circles or intricate movements (such as the bottom text on a Benchy) seems to peel up and stick to the nozzle, i am running the first layer at 1, yes 1 mm/s for the speed. this seems to fix the issue.

and i have used 5 different spools of PETG, only 1 adheres, Grey EONO from amazon!!!

show how tricky this is, but i have got something to work some how. so only up from now on i hope :o

You do seem to have had to go extremes to get something working ! As I write using Tufnol clamped to a glass bed and PVA glue stick I have a 75 mm diameter semi pressure bottle printing using Oosnest PET-G Print temp 245C initial temp 245C bed 70C. Speed printing 70mm/S initial Speed 35mm/S oh and on an Ender 3 pro

It does feel like that. im using a ender 3 pro too.. I tried the Stock bed, the microporous buildtak and finally glass superheated. it works well and pops off once cold. i use 245 Inital and 220 for the rest as it seems to have zero stringing when its cooler. i can feed the petg through the nozzle as low as 180!just trying to fix the issue of small detailed first layer from sticking to the nozzle. the feature in cura which means the quick change in direction is slowed down seems to work well. ive got that set at 0.5mm/s as soon as intial layer is done i go up to 50mm/s and it prints lovely. i also level the bed using a BLtouch which is calibrated with a feeler gauge to exactly 0.2mm. so when it reads zero the nozzle touches the bed! PLA printed like a dream on anything, god i love PLA

I don't use BLtouch but level the bed at each corner with 0.07mm (3 thou to us oldies) Steel shim stock. The general opinion on the forum is that with a flat bed such as glass auto bed levelers are more trouble than they are worth.
Because we use this simple printer to support a small design group we use it every day and the Tufnol and the setting work for us all the time usin multiple materials as designs require,

Attachment 16186


This is how the set up looks the piece on the bed plat is Pet-g

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Originally Posted by Gambo

I don't use BLtouch but level the bed at each corner with 0.07mm (3 thou to us oldies) Steel shim stock. The general opinion on the forum is that with a flat bed such as glass auto bed levelers are more trouble than they are worth.Because we use this simple printer to support a small design group we use it every day and the Tufnol and the setting work for us all the time usin multiple materials as designs require,

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I am starting to feel, especially with firmware upgrades etc that the BL touch is more hassle than its worth...im thinking about just using it as a real assurate Z end stop and not using its bed leveling features as its not exactly hard to get a level bed... one big mod i made which reduced PETG warping down to nothing was modifying the hotend cooling. i found with the stock hotend ender metal cover it blew on the print regardless. now i have fitted a much better one that doesnt blow any air over it if the part cooling fan is on. that helped alot with bed adhesion

Give Tufnol a try I think it will transform your experience if you are in UK Trent Plastics is a ready source at www.trentplastics.co.uk I bought a 1200mm x300mm and made 5 ender bed sized pieces for less than £4 each

or get a sheet of PEI.

I've had no problems with pet or pet-g on that at 50c.

And yeah the whole 'autolevel' thing is mostly a waste of time.
It's cheaper for companies to add a cloned 'bl-touch' than to actually source, proper, flat printbeds.

Agreed........

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Originally Posted by curious aardvark

or get a sheet of PEI. I've had no problems with pet or pet-g on that at 50c. And yeah the whole 'autolevel' thing is mostly a waste of time. It's cheaper for companies to add a cloned 'bl-touch' than to actually source, proper, flat printbeds.

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very true. hence why glass seems the way to go. only if i can manage good enough adhesion though. interesting about the Tufnol, never heard of it been used before so i may check it out.

It is the classic material used in the states Known as Garolite LE

The Glass bed gives the necessary flatness and the Tufnol gives the grip with the help of adhesion promotors some times. But you do need to clamp it down all round to ensure it doesn't warp.