Help me dial this PETG in...

[WobblyHand]

So I thought I would try PETG. I'd like to print this box eventually. I made a couple of prototype prints in PLA and they came out rather well.

So I changed my steel plate to satin and sort of adjusted the Z so it wasn't too high. I did notice that I will eventually need to address leveling the whole bed, but that is not the main issue. Then I printed a test file just for figuring out the magnet in a pocket thing. It came out ok. I printed it horizontally like this.

If you look carefully at the back side, (the first picture) you can see a faint rectangle. That's because some dope, not saying who, forgot to clean off the test pattern before printing this. Guess it is ok, but I'm soliciting advice. Then I thought, that's nice but what I really want to know is how it will print if the piece is standing on the long narrow edge, like it would be in the box. So I moved the piece on it's long narrow edge and sliced it with supports everywhere. And printed it at 0.2mm quality. After I peeled off the supports this is what I have.

Not so pretty. Actually kind of ugly. Nowhere as nicely printed as the PLA. Lots of little nubs, banding across where the pockets are and some overhanging at around 29mm in Z. Is this as good as it gets? If not, what can I do to improve the vertical wall quality? I exported my config.ini and changed the extension to .txt to get the forum to accept the upload.

Thanks for any and all observations.

 

[great white]

When you say "changed the Z" are you taking about layer height or Z offset?

Z offset never changes once you have it set.

Layer height is dependent on the nozzle size, not the layer adhesion you want.

I generally run a layer height of approx 50% nozzle diameter and PETG prints out as easily as PLA for me.

Blobbing and such artifacts are usually related to temperature and flow. If you haven't, confirm you're getting the flow rate your slicer program thinks you are. Lots of tutorials on the web about how to measure it. PETG also prints hotter than PLA, so you have to pay attention to things like build plate temps, cooling schemes, etc.

Also, with those hotter temps, it becomes more likely stock hot ends just won't be able to keep up at decent flow rates. If that turns out to be the problem, the only solution is a better hot end. I run an E3D volcano hot end and have no problems even using a 1.2 nozzle at high flow rates.

 

[WobblyHand]

When you say "changed the Z" are you taking about layer height or Z offset?

Z offset never changes once you have it set.

Layer height is dependent on the nozzle size, not the layer adhesion you want.

I generally run a layer height of approx 50% nozzle diameter and PETG prints out as easily as PLA for me.

There is a line defect in the part around 29mm up from the sheet. Not talking about Z offset. Mine is probably not perfect, but not awful.
I am using a 0.4mm nozzle, and 0.2mm layer depth.

The first two pictures are printed flat on the plate. ( 32.2mm x 95.5mm on the plate.) They came out ok enough and the surface quality is good, I think. However, I am a beginner, and find it difficult to detect nuances, because I have never used the material before.

The second two pictures are of this test piece printed vertically, with only 3mm x 95.5mm touching the plate. Like this:

My enclosure that I printed in PLA came out ok. This test print in PETG of the same magnet wall, (the 3rd and 4th red photos) did not print as well. I am wondering what I can change to improve the vertical wall quality.

 

[great white]

There is a line defect in the part around 29mm up from the sheet. Not talking about Z offset. Mine is probably not perfect, but not awful.
I am using a 0.4mm nozzle, and 0.2mm layer depth.

The first two pictures are printed flat on the plate. ( 32.2mm x 95.5mm on the plate.) They came out ok enough and the surface quality is good, I think. However, I am a beginner, and find it difficult to detect nuances, because I have never used the material before.

The second two pictures are of this test piece printed vertically, with only 3mm x 95.5mm touching the plate. Like this:
View attachment 427376
My enclosure that I printed in PLA came out ok. This test print in PETG of the same magnet wall, (the 3rd and 4th red photos) did not print as well. I am wondering what I can change to improve the vertical wall quality.

I wouldn't print that vertically.

Your layer lines are going to be such that when you press in your magnets, you risk splitting the layers apart. I'd print that flat for the best strength in the direction of the load and minimizing the amount of filament needed to print.

Supports are wasted filament (if you can orient to not need them), you want to try and minimize that while still making good quality prints.

 

[7milesup]

@great white He is printing it vertically because when he prints the box (@WobblyHand's first post) they have to print vertically because of the walls of the box.
PETG is much more prone to stringing and blobs than PLA. Temp and retractions help with that. I have printed a lot of PETG with a 0.4 nozzle at a 0.2 layer height. Some of my prints turned out great, and some not so much. I found that brands of filament make a difference also. I recently tried to print some PETG from a new company that I was trying and had one heck of a time getting it to stick to the bed.
Your print shows a lot of ghosting. I am afraid I don't have an answer for that but an interweb search might help. Sorry about that.

 

[WobblyHand]

I wouldn't print that vertically.

Your layer lines are going to be such that when you press in your magnets, you risk splitting the layers apart. I'd print that flat for the best strength in the direction of the load and minimizing the amount of filament needed to print.

Supports are wasted filament (if you can orient to not need them), you want to try and minimize that while still making good quality prints.

Not as a stand alone part, I agree. But this is a test piece, in the same orientation as the box. If you observe, the box has vertical walls. I can't think of a way to print a 5 sided box without something being vertical. The support is for the pocket which is overhanging.

@7milesup yes, exactly. Ghosting? It's a term to search for, thanks.

 

[WobblyHand]

@great white He is printing it vertically because when he prints the box (@WobblyHand's first post) they have to print vertically because of the walls of the box.
PETG is much more prone to stringing and blobs than PLA. Temp and retractions help with that. I have printed a lot of PETG with a 0.4 nozzle at a 0.2 layer height. Some of my prints turned out great, and some not so much. I found that brands of filament make a difference also. I recently tried to print some PETG from a new company that I was trying and had one heck of a time getting it to stick to the bed.
Your print shows a lot of ghosting. I am afraid I don't have an answer for that but an interweb search might help. Sorry about that.

For the nozzle my first layer is at 240C, other layers at 250C.
For the bed first layer is at 85C, other layers at 90C.
The default is to keep the fan always on & enable auto cooling. Don't understand that, but hey...
Filament is Prusament PETG. Thought I'd start out with a known thing so the PrusaSlicer defaults might be reasonable.

Off to search ghosting.

 

[7milesup]

I would turn the fan off for the first few layers, and then only 40% or so for the remaining. PETG and ABS don't really care for having the fan running (especially ABS, don't even run the fan) but PLA benefits from having the fan on.

 

[great white]

For the nozzle my first layer is at 240C, other layers at 250C.
For the bed first layer is at 85C, other layers at 90C.
The default is to keep the fan always on & enable auto cooling. Don't understand that, but hey...
Filament is Prusament PETG. Thought I'd start out with a known thing so the PrusaSlicer defaults might be reasonable.

Off to search ghosting.

Since you need to print vertical, fan speeds are also critical. The fan speed is to cool the filament faster as you are around the holes in order to keep the filament from sagging. It's not as critical when printing "detents" like you are and using full supports, but it still has an effect.

Fan speeds are absolutely critical if your print has any "bridging" areas. Your print is using supports, so bridging isn't as big a concern.

I don't remember what my temp settings are for PETG, but I don't jump up and down temps on the layers. I set my print temp and set my bed temp and let it go. What I do though is vary my fan speeds.

I generally have "0" fan speed on the first couple layers and then my settings depend on the particulars of the object and the filament I'm using.

For example; when I print ABS, my fans are "OFF" for the entire print. Fan tends to increase the (already horrible) warping tendencies of ABS, which is bad enough to start with.

Do a google on 3d printing and fan speeds/cooling. Lots of info out there...


Edit: seems 7miles and I were pretty much typing the same thing at the same time! LOL!

 

[WobblyHand]

Ghosting can be related to belt tension. https://help.prusa3d.com/article/ghosting_1801
I can try loosening the X and Y axis belts. Ok, ran the Calibration Belt Test. X: 242-234, Y: 266-272. The belt tension should be between 240-300. So it looks like the X needs a little loosening. Something to fiddle with, and maybe even fix.

Found the Expert section on Cooling in the slicer. Have no idea why the default is 100% on. Changed that. I have screwed around with enough setting to forget stuff. Going to have to save these settings... done.

Dragged in feet first into the rabbit hole, falling...