eviglotti
Posts: 8
Joined: Tue Feb 06, 2018 3:47 pm

PETG Material

Tue Feb 06, 2018 3:53 pm

Hello,

I am fairly new to S3D and have been using PLA and my Robo3D R2 printer with a PEI sheet now successfully. However, now I need to print with PETG and support recommended that the "best place to start would be with the ABS profile, then Click the Green + to add a new Material that you can call PETG. You can then check the PETG section of the Materials Guide for help on getting the settings dialed in."

I started by changing the bed temp to 85 and extruder to 240 and turned the fan on to 100% on layer 2 and up like I have with PLA. However, what other settings have folks out there changed when using the ABS profile as a starting point for PETG? I see the Materials Guide talks about changing retraction settings to reduce stringing and dealing with blobs and zits, but what values have each tried, or is this so specific to the printer that I should ask someone in a Robo forum on this?

Thanks!

MichaelHerron
Posts: 112
Joined: Mon Mar 16, 2015 1:36 pm

Re: PETG Material

Thu Feb 08, 2018 11:46 am

First, keep your fan off.
Print at as low a temp as you can that gives you good layer adhesion.(240 is a good starting point)
Retract distance should be about 10X your nozzle diameter. (4mm for .4mm nozzle)
You may want to also add a little Retraction Vertical Lift.
Print speeds are generally slower than ABS

arhi
Posts: 368
Joined: Thu Oct 06, 2016 4:13 pm

Re: PETG Material

Thu Feb 08, 2018 12:07 pm

I'm not PETG expert in no way but
MichaelHerron wrote:First, keep your fan off.
? I got way better results with fan on? and most petg material manuals state fan should be on
MichaelHerron wrote: Retract distance should be about 10X your nozzle diameter. (4mm for .4mm nozzle)
you want to run 240+ temps on all metal hotend as at 240C ptfe start to degrade and evaporate some very toxic gasses ... all metal hotends don't usually allow over 3mm retraction (you will get throat blockage quickly) .. I get no strings and no blobs, zits, holes.. with 1mm retraction 0.3mm coasting and 1mm wipe
gcodestat integrates with Simplify3D and allow you to
Calculate print time accurately (acceleration, max speed, junction deviation all taken into consideration)
Embed M117 codes into G-Code
Upload your G-Code directly to Octoprint
open source and unlicence

eviglotti
Posts: 8
Joined: Tue Feb 06, 2018 3:47 pm

Re: PETG Material

Thu Feb 08, 2018 12:09 pm

Thank you so much, this is super helpful.

1. I am noticing that when I print a sphere or underside of a bowl, the top last few layers have some holes in it. I am set to 3 top solid layers, should I increase that or is it more about decreasing the speed for either that part or the whole print (currently it's set to 3000 mm/min with "adjust printing speed for layers below 15 seconds" where I know that the last few little layers of a sphere are faster than 15 sec)

2. Every time I print with PETG onto my PEI plate, it is virtually impossible to remove. I get good bed adhesion for sure :) but it takes a lot of effort and inevitably pieces of the skirt doesn't come off no matter how much scraping or alcohol I use and I have to sand it off. Should I go old-school and start using a glue stick or something else or is my bed temp too high?

Thanks!

arhi
Posts: 368
Joined: Thu Oct 06, 2016 4:13 pm

Re: PETG Material

Fri Feb 09, 2018 4:23 am

eviglotti wrote: 2. Every time I print with PETG onto my PEI plate, it is virtually impossible to remove. I get good bed adhesion for sure :) but it takes a lot of effort and inevitably pieces of the skirt doesn't come off no matter how much scraping or alcohol I use and I have to sand it off. Should I go old-school and start using a glue stick or something else or is my bed temp too high?
lift your head a bit for the first layer, compared to ABS/PLA PETG must be printed "higher" - without squashing it to plate too much.. if that don't help drop temp of the bed by few deg.

use g-code tab, global offset, Z, 0.02 and increase by 0.02 till you get first layer that's nice and removes easily.. if you start to get "ugly" first layer and it's still sticking too hard, drop the bed temp
gcodestat integrates with Simplify3D and allow you to
Calculate print time accurately (acceleration, max speed, junction deviation all taken into consideration)
Embed M117 codes into G-Code
Upload your G-Code directly to Octoprint
open source and unlicence

horst.w
Posts: 777
Joined: Fri Oct 17, 2014 4:00 pm

Re: PETG Material

Fri Feb 09, 2018 4:40 am

Its the similar problem what we talk about here:

https://forum.simplify3d.com/viewtopic.php?f=9&t=9362

Regards
horst.w
GER

eviglotti
Posts: 8
Joined: Tue Feb 06, 2018 3:47 pm

Re: PETG Material

Sat Feb 10, 2018 2:54 am

Thanks so much.

1. Interesting about the fan, this page seems to indicate to leave the fan on for PETG: https://www.simplify3d.com/support/mate ... uide/petg/

2. Good info on the retraction distance. I am currently set to 1.5mm retraction, no coasting at all, and wipe nozzle of 5mm. Maybe I'll turn on coasting with 0.3mm.

3. For this link talking about the top of a sphere, the idea is that you leave all of your settings as is, but then create a second process for the very top of the sphere, and if so, what setting are we changing? Is it the "outline/perimeter shells" which I have currently set to 2? or would just doing 100% infill and slowing down help?

Thanks!

horst.w
Posts: 777
Joined: Fri Oct 17, 2014 4:00 pm

Re: PETG Material

Sat Feb 10, 2018 4:23 am

... it is depending very hard to the modell you want to print. Someone is only able to show you critical points such as a hollow sphere and a massiv filled sphere. This you can transfere to every body with a dome-like shape.

I want to create some exaples for you this evening (now 10:00 am) but the best would be, you attache your factory-file here.

You know the new S3D material advices here: https://forum.simplify3d.com/viewtopic.php?f=8&t=9300

So as the printing is depending from the model, the cooling is also depending from the air-mouth and the kind of fan.
e.g. a radial fan is much stronger than an axial fan and if your air-mouth is like an air-gun the airstream will be pointed to much and blows holes into the hot materials. Also the direction of the airstream is important, if it touchs the nozzle to directly, the nozzle will be cooled down and get closed.
In one case it may be ok with 100% cooling, in a different case it is pure poison.

Actually I run a PETG print with 190°C and 10% cooling but the objects are flat, infill 30% without any problems.
The attached pic shows 2 of 4 parts.

H.
PETG 20180210_101428.jpg

arhi
Posts: 368
Joined: Thu Oct 06, 2016 4:13 pm

Re: PETG Material

Sat Feb 10, 2018 11:32 am

horst.w wrote:Actually I run a PETG print with 190°C
that can't be some regular PETG, or your temp sensor is out of cal :)
gcodestat integrates with Simplify3D and allow you to
Calculate print time accurately (acceleration, max speed, junction deviation all taken into consideration)
Embed M117 codes into G-Code
Upload your G-Code directly to Octoprint
open source and unlicence

eviglotti
Posts: 8
Joined: Tue Feb 06, 2018 3:47 pm

Re: PETG Material

Sat Feb 10, 2018 4:57 pm

Cool, thank you.

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