help with inland PETG?
greeting,
I was wondering if anyone has had experience printing with inland petg on a prusa and might share some of their settings? My PLA prints look great but my PETG look pretty bad. I've been trying for two weeks now trying to get the settings dialed down but not quite there yet. my calibration cubes look ok but I don't get the issue of the artifacts on curves so I've been testing on the benchy boat and stopping after I see the issue.
I've messed with the z-height a little, bed temp at 85, nozzle at 235, and speed at 70% so my first layer is looking pretty good i think.
I've tried changing fixing some of the stringing by setting the retraction amount from .8 to 3.8 and the retraction speed to 64 from 32. I also tried messing with the extrusion multiplier and set it to .9 and 1.03
I use the prusa slic3r software which I've tried the prusa PET profile as well as the generic PET (which was what I would start with before messing with the settings) I've tried with 1.5 and 2 layer height as well as the linear advance ones. It also seems that I have to set the speed down manually in my tune settings on my printer since it doesnt seem to really slow down if I set it in the g-code.
I guess for background info, my printer is on top of a cement block thats wrapped with a yoga mat to reduce noise and I also have a noctua mod on my one fan to further reduce noise. since my PLA prints look pretty good, I don't think those things would contribute to the issue.
so yeah, I can't quite figure out how to get rid of these wavy layers, issues at the front of my benchy, as well as the intense stringing.
Thanks for any help or hints!
first effort https://imgur.com/gallery/cHXj3op
second effort https://imgur.com/gallery/U7C1gpm
third effort https://imgur.com/gallery/QFM9UNU
Re: help with inland PETG?
my first impression looking at the photos is still too hot.
i'm using hatchbox PETG which i'm still trying to dial in myself.
however i'm running at 245deg with that filament.
have you tried making a heat tower and running at different temperatures to see if 235 could be improved on?
i had come down from 260-270 degrees on PETG i was using lots of cooling and the fan was causing the layers to not bond. i shutdown the fan then lowered the temperature i have my bridging at 50% and i vary the fan between 0 and 50% unly if the layer time is under 30 seconds.
i had better luck reducing my retraction speed to 10mm/s and .5mm for the length of retraction.
but i'm still going through different tests to make it nicer.
“One does not simply use a picture as signature on Prusa forumsâ€
Re: help with inland PETG?
my first impression looking at the photos is still too hot.
i'm using hatchbox PETG which i'm still trying to dial in myself.
however i'm running at 245deg with that filament.
have you tried making a heat tower and running at different temperatures to see if 235 could be improved on?
i had come down from 260-270 degrees on PETG i was using lots of cooling and the fan was causing the layers to not bond. i shutdown the fan then lowered the temperature i have my bridging at 50% and i vary the fan between 0 and 50% unly if the layer time is under 30 seconds.
i had better luck reducing my retraction speed to 10mm/s and .5mm for the length of retraction.
but i'm still going through different tests to make it nicer.
“One does not simply use a picture as signature on Prusa forumsâ€
Re: help with inland PETG?
thanks, I'll try the heat tower.
Some of my test prints were at 235 which I thought was ok but maybe I'll try 230.
My first 3 layers are set to fan-less which I don't think there's as much waviness but I haven't tried keeping it off for the whole print.
I haven't thought about reducing the retraction speed or length amount since I am getting some stringing and it sounds counter intuitive but I'll give that a shot too.
Re: help with inland PETG?
you might want to explore slowing the speed down. if you go too fast the petg doesn't have time to solidify and the nozzle moving to the next layer pulls on the semi liquid layer below and it can also look like the nozzle was too hot when it was just moving too fast.
i don't remember my speed settings but i do remember going with ABS speed settings to start.
“One does not simply use a picture as signature on Prusa forumsâ€
Re: help with inland PETG?
I was also having a lot of trouble printing Inland PETG on my Prusa MK2S. I read a lot of tips from other people and played around with various settings for many weeks. My biggest problem was getting it to stick to the PEI sheet on the Prussa. I ended up buying a Build Tek magnetic print bed kit. This is similar to what is used on the MK3. The magnetic base is peel and stick. I cleaned the PEI surface and stuck it down. I was disappointed in the performance of the Build Tek surface. It worked very well for PLA, but the PETG just would not stick. I ordered a sheet of Gecko Tek and applied it to the backside of the Build Tek flex plate. After spending a day dialing in the height settings I was getting prints to stick.
I am doing everything the opposite of what popular wisdom says to do as far as printing PETG. I am seeing very little stringing and no blobs. I edited the materials_i3_mk2.json file to add a selection for Inland PETG. Basically, I print at full speed (100%) with a bed temp of 90 and a nozzle temp of 230 for the first layer and 235 after that with the fan on full and a first layer height of 0.25mm. The idea here is that I was seeing lots of globs on the first layer with a hotter nozzle and no fan. So I reduced nozzle temperature to reduce the globs and used the fan to harden the plastic quickly (helps with the stringing). Raising the nozzle temperature after the first layer gives the model a nice sheen that I was not seeing at the lower temperature. I know it goes against conventional wisdom, but it works for me.
Here is the block I added for Inland PETG. After adding it I went back and renumbered all the other filament blocks. When I change spools, I edit the file and change “first”: 0,
To “first": 1, for the spool I just put on. You also have to change the current # 1 to 0. Doing this puts the current spool at the top of the list as the default filament. Even though I told it to print the first layer at 50% it still prints at 100%. Same for max print speed. It seems to ignore these settings.
"inland_pet": {
"first": 1,
"sort": 6,
"name": "inland_pet",
"label": "Inland PETG",
"infill": 20,
"infillRange": [
0,
80
],
"quality": {
"detail": {
"first": 0,
"sort": 1,
"name": "detail",
"label": "Detail - 0.1 mm",
"parameters": {
"layer_height" : 0.1,
"top_solid_layers" : 9,
"bottom_solid_layers": 7,
"perimeters" : 2
}
},
"optimal": {
"first": 1,
"sort": 2,
"name": "optimal",
"label": "Optimal - 0.15 mm",
"parameters": {
"layer_height" : 0.15,
"top_solid_layers" : 7,
"bottom_solid_layers": 5,
"perimeters" : 2
}
},
"normal": {
"first": 0,
"sort": 3,
"name": "normal",
"label": "Normal - 0.2 mm",
"parameters": {
}
},
"draft": {
"first": 0,
"sort": 4,
"name": "draft",
"label": "Draft - 0.35 mm",
"parameters": {
"layer_height": 0.35,
"perimeters" : 2,
"top_solid_layers" : 4,
"bottom_solid_layers": 3,
"external_perimeter_extrusion_width": 0.7,
"extrusion_width": 0.7,
"infill_extrusion_width": 0.7,
"perimeter_extrusion_width": 0.7,
"solid_infill_extrusion_width": 0.7,
"solid_infill_speed": 60,
"top_infill_extrusion_width": 0.45,
"top_solid_infill_speed": 50
}
},
"default": {
"first": 0,
"sort": 99,
"name": "default",
"label": "",
"parameters": {
"start_filament_gcode": "M900 K45",
"cooling": 1,
"first_layer_height": 0.25,
"filament_max_volumetric_speed": 10,
"disable_fan_first_layers": 0,
"fan_always_on": 1,
"first_layer_speed": "50",
"max_print_speed": 50,
"first_layer_temperature": 230,
"first_layer_bed_temperature": 90,
"temperature": 235,
"bed_temperature": 90,
"min_fan_speed": 30,
"max_fan_speed": 100,
"bridge_fan_speed": 100,
"fan_below_layer_time": 20,
"filament_diameter": 1.75,
"extrusion_multiplier": 1,
"external_perimeter_extrusion_width": 0.7,
"extrusion_width": 0.7,
"top_infill_extrusion_width": 0.45,
"perimeter_extrusion_width": 0.7,
"solid_infill_extrusion_width": 0.7,
"infill_extrusion_width": 0.7,
"ooze_prevention": 1
}
}
}
},
As I said, this is working for me. I hope it helps.