Re: Problems Dialing in my PETG Settings

[MusicManAsman]

Hi all!
So i just completed my first larger print using PETG (eSUN solid purple PETG), and ran into a few issues that i was hoping y'all could help me with! I've included a number of pictures, with each picture of the print (the inverted Ciii cooler) highlighting an issue that i saw, from the stringiness to the bumps on the main top layer to the inconsistent layering to the (what i think) is bad bridging...i've also included screen shots of each page of my settings in Simplify3D...any help or advice would be most welcome! I've been trying to dial in my PETG settings the last few days, and while i've made some major improvements in some smaller prints (i've been scouring the forums and advice pages about PETG), this larger one definitely showed me that i am not quite there yet. Thanks in advance, i very much appreciate the help!!

[airscapes]

I am using eSun White PETG on a MakerGear M2 with a .35 nozzle. I print at 245C and bed at 85C. I will assume you have an accurate digital caliper. Pull out about 4 yards of filament and measure it every 6-12 inches and enter that average into the Other Tab. Mine was running fairly close to 1.75 then recently dropped to 1.69. Right now it is averaging around 1.71 and with that set I have my E multiplier at 92. This is producing a slightly fat thin walled cube but for what I am doing currently I would rather be slightly fat then under..

For retraction I am using 1.10mm at a retraction speed of 60mm. Also I don't print anything faster than 60mms for big things and 45 for small things.
I have had good luck with this product but it is defiantly more gooey than other filaments.
I have seen the bumps in the surface.. probably moisture..
I am currently printing a larger measuring cube just to see how it looks.. used 20% infill should have probably only done 10% a PETG is really strong stuff
Also printed a lot of parts for an E-nable hand I am making for certification with the group http://enablingthefuture.org/ White parts are the PETG
I added the factory file for the cube so you can see the settings I am using..

bakerscubev3 PETG.factory

(2.42 MiB) Downloaded 260 times

[MusicManAsman]

Hi all!
Apologies for double-posting, but i think i accidentally deleted my initial post, so here it is! I also realized that i can apparently only upload 3 photos at a time, so i am just uploading three showing some of the issues i'm running into and i'll post my settings below.

So i just completed my first larger print using PETG (eSUN solid purple PETG), and ran into a few issues that i was hoping y'all could help me with! Each picture of the print (the inverted Ciii cooler) highlights an issue that i saw, from the stringiness to the bumps on the main top layer to the inconsistent layering to the (what i think) is bad bridging...i've also included screen shots of each page of my settings in Simplify3D...any help or advice would be most welcome! I've been trying to dial in my PETG settings the last few days, and while i've made some major improvements in some smaller prints, this larger one definitely showed me that i am not quite there yet. I am printing on a Monoprice Maker Select Plus with the MicroSwiss all-metal hotend .4mm nozzle. Thanks in advance, i very much appreciate the help!!

Sorry for the exceptionally long list of my settings, but i wanted to include everything i could! Thanks again everyone!

Nozzle Diameter: .4mm
Extrusion Multiplier: .89
Extrusion Width: Manual, .4
Retraction Distance: 3mm
Extra Restart Distance: 0
Retraction Vertical LIft: .6
Retraction Speed: 3600
Coasting Distance: .2
Wipe Distance: 5
Primaray Layer Height: .1750
Top Solid Layers: 4
Bottom Solid Layers: 4
Outline/Perimeter Shells: 1
Outline Direction: Inside-Out
First Layer Height: 90%
First Layer Width: 100%
First Layer Speed: 25%
Optimize Start Points for Fastest Printing Speed
Skirt Layers: 1
Skirt Offset: 4
Skirt Outlines: 3
Internal Infill Pattern: Grid
External Infill Pattern: Rectilinear
Interior Infill Percentage: 100%
Outline Overlap: 10%
Infill Extrusion Width: 103%
Minimum Infill Length: 2
Combine Infill Every 1 layer
Bed Temp Layer 1: 75
Bed Temp Layer 2: 80
Extruder Temp Layer 1: 235
Extruder Temp Layer 2: 230
Fan Speed Layer 1: 0
Fan Speed Layer 2: 100%
Default Printing Speed: 2000
Outline Underspeed: 50
Solid Infill Underspeed: 75
X/Y Axis Movement Speed: 12000
Z Axis Movement Speed: 1200
Adjust Printing Speed for Layers below 15 sec
Allow Reduction Speeds down to 20%
Unsupported Area Threshold: 10
Extra Inflation Distance: 1
Bridging Extrusion Multiplier: 140
Briding Speed Multiplier: 125
Use Fixed Bridging Infill Angle: 0
Apply Bridging Settings to Perimeters
Filament Diameter: 1.7 (measured with calipers)
Force Retraction Between Layers
Perform Retraction during Wipe Movement
Only Wipe Extruder for outer-most perimeters
Avoid Crossing Outline for Travel Movements
Maximum Allowed Detour Factor: 3
Non-manifold Segments: Heal

[SWCNT]

Hi,

In general, I would say your biggest issues are speed/cooling with some tweaks needed to extrusion.

Bottom of Part

From what I see, you are printing with no supports, which explains the extrusion mess I marked. If the bed is 75-80C, there's no way those layers are cooling down enough not to deform (they are way too close to the bed). So you get a very messy perimeter, and that plastic is going to coat your nozzle and probably get deposited else where on the part and cause additional issues. If you want to do that with no support, you need to print the perimeter slower for this section (5 mm/s) and ideally smaller layer heights (~0.1 mm, or 0.05 mm if your printer can handle it). That's where Simpilfy3D variable settings come in handle. I basically never print a part with one profile, unless it's a fast and sloppy run. You are also going to run into a barrier somewhere (at some point) with using a stock cooling fan. I find nearly every commercial printer is good for PLA, but once you get into other plastics, various design issues start to show up. But ultimately, it depends on what you're doing and how fussy you are.

Side of Part

It looks like you are trying to print this feature with no supports too. I didn't see any support settings in your profile. If you are, then you need to slow down on the overhangs so the plastic doesn't drupe. You have a speed and cooling problem here, if I'm understanding how you printed correctly. Usually you want to be around 5 mm/s for doing stuff like that without supports, also, the lower the layer height the more subsequent layers make up a curve (smaller incremental layer building), which helps a lot for no support PETG prints. I'm not sure why your bridge speed multiplier is 125%. You should be slowing down for bridges. I would recommend looking at variable settings and make a different profile for the more difficult sections. One-size fits all doesn't work if you want beautiful PETG parts.

Top of Part

Humps:
Those humps indicate something is wrong with the layers below. Could be that your nozzle deposited material here which happens easily with PETG due to its stringiness. It can also happen from a bit too much extrusion on the infill, which can easily happen when you are using 100% fill. When I print PETG, I decide whether I care about strength or quality. If quality, I go with a bit of underextrusion on the 100% infill. The size of the part matters here. For smaller prints (few inches) PETG is more forgiving when you run with a bit of overextrusion (I see the 103% on your infill), but with bigger parts, that bit of overextrusion that some people suggests (works really well with transparent PETG) can case surface deformations at higher layers. If I want strength, I use a bit of overextrusion, but then I always plan on sanding the part to make the surface smooth (if it's for a customer).

Zits:
Those zits/rings are most likely caused by the nozzle deforming the previous layer while printing the current layer. Your print speeds are not that high--good thing--but your part isn't that big and your bed is 75-80C. So you need to consider the ambient temperature around that part. It's not cooling down as much as you think especially since you are only using a stock cooling fan. When the 230 nozzle passes <0.2mm from the previous layer you are going to get heat deformation, which appears as zits/rings/bulges.

Perimeter separation:
At first I thought you had multiple outline perimeters, then I saw you had it set for 1. On the picture, you can see how the perimeter layers aren't bonding. I would use 2-3 perimeters for this part, but to really make that curve clean you should decrease the layer height to the ~0.1mm. That's where Simpilfy3D variable settings come in handle.

Strings
My first change would be to set the min layer time to 30 seconds and the speed reduction to 70% (making the min outline 5 mm/s). Looking at your print, the biggest stringing issues occur on the smallest features, 10 seconds isn't long enough for the previous PETG layer to cool enough for zero deformation and no strings. The outline also looks a bit smooshed, which can be caused by inadequate cooling.

I would also suggest drying the PETG before using it when buying from overseas (assuming you aren't in China) because even if the filament is packed with desiccant and sealed, you have no idea how long it's been in that state and no seal is perfect. I've ordered "new" PETG from eSun and Hatchbox and both had issues with moisture that gave me many headaches when I first started with PETG. Moisture issues will usually show up as random underextrusions--hard to catch on infills, but easy to spot on perimeters. If it's really wet you can see bubbles or holes in the filament when it prints a layer. For 8+ hr prints, I print the PETG from a printdry filament system.

[swoop]

great advice and visuals much appreciated! PETG can be very stringy when printed too cold IMO. Generally I use at least 2 shells on every print. It can be really difficult to get awesome layer adhesion with petg above 50+ mm/s.