Patterns appearing on curves / corners - 4.8.0 and 4.7.x - not on 4.6.1

[msteele999]

Application version 4.8.0

Platform Windows 7 x64

Printer Sovol SV01 (included with Cura 4.8.0 / copied from Ender 3 in 4.6.1)

Reproduction steps

1. Using 'identical' filament profiles and slicer settings, slice in Cura 4.6.1 and 4.8.0.
2. Print
3. Observe the difference between the Cura 4.6.1 sliced print (clean) and the 4.8.0 sliced print (patterns)

Screenshot(s) 4.8.0 results:

4.6.1 results:

Project file

4.8.0_patterns_on_curves.zip

4.6.1_no_patterns_on_curves.zip

Additional information

This was originally reported on the Glitch on Slow Downs issue - but that has since been closed as resolved - so this must be a different issue.

Mark

[msteele999]

An additional picture of side by side

I stopped the 4.8.0 print due to the pattern showing up

[bill-orange]

It could still be the same issue, I think. For your particular machine you may have to change a couple of settings for 4.8. In mesh fixes try setting Maximum resolution to 0.25mm and Maximum Deviation to 0.025 mm.

Your layer height is pretty high. Maybe drop that to 0.18 mm. If that doesn't help, I'm out of ideas.

[msteele999]

I'll try the mesh changes, however I recall that causing other issues. 0.5 and .05 have fixed a lot of other problems for me.

The resolution test I'll try later today, however that really slows down the print time.

On Fri, Nov 27, 2020, 10:18 bill-orange notifications@github.com wrote:

It could still be the same issue, I think. For your particular machine you may have to change a couple of settings for 4.8. In mesh fixes try setting Maximum resolution to 0.25mm and Maximum Deviation to 0.025 mm.

Your layer height is pretty high. Maybe drop that to 0.18 mm. If that doesn't help, I'm out of ideas.

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/Ultimaker/Cura/issues/8839#issuecomment-734881986, or unsubscribe https://github.com/notifications/unsubscribe-auth/ABRMUYJ3G34ZOKTGMY4W7WLSR67MJANCNFSM4UEHZRMA .

[Liger0]

Use a straight new profile, don't import old ones.

[msteele999]

These are not imported. Made from scratch.

On Sun, Nov 29, 2020, 11:40 Liger0 notifications@github.com wrote:

Use a straight new profile, don't import old ones.

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/Ultimaker/Cura/issues/8839#issuecomment-735421654, or unsubscribe https://github.com/notifications/unsubscribe-auth/ABRMUYLUSXJR66IKDKHLHFTSSJ2QNANCNFSM4UEHZRMA .

[Liger0]

But is it a default 4.8 profile?

[msteele999]

Yes. And that looked horrible. So then I started tweaking it to match my 4.6 profile, which looks phenomenal.

On Sun, Nov 29, 2020, 13:03 Liger0 notifications@github.com wrote:

But is it a default 4.8 profile?

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/Ultimaker/Cura/issues/8839#issuecomment-735432504, or unsubscribe https://github.com/notifications/unsubscribe-auth/ABRMUYJWS6DPC26F7SUOELDSSKEGDANCNFSM4UEHZRMA .

[Ghostkeeper]

We can't really help you with print quality issues. Each print quality issue can have hundreds of causes. We've made thousands of changes between 4.6 and 4.8. We're unable to reproduce those print quality issues on our own printers with our own filaments and so we're unable to verify whether we fixed them if we make any new changes.

From your results I can't tell what Cura is really doing wrong here. Is there something unexpected in the g-code output of Cura? Are there any settings that you think should be changed in the defaults for your printer+nozzle+material+quality?

[msteele999]

Thank you for your reply. It's very disappointing but I appreciate that you did not give me the 'it's not an Ultimaker printer so go figure it out yourself' response.

I have gone through literally 50 iterations of the profile, starting with the default and making modifications to everything I could think of that would affect the external skin of a print in a repeatable and obvious pattern.

When you printed the file using the 4.8.0 profile I supplied on your printer, what were the results? Did you also see the pattern in the perimeter that I showed in my pictures?

I provided both the gcode and the project files for the model in 4.6.1 and 4.8.0 hoping you would see what is happening in the gcode - it's localized to the one corner and I was hoping you could isolate the issue. I can get the same results with multiple materials at multiple material settings. The ONLY thing that resolves the issue is going back to 4.6.1

I understand if you are not willing to move any further with this issue as it seems to be just one person having the issue. I will state that when I use ideaMaker I don't see the pattern either - but I much prefer Cura and I have invested a significant amount of time and energy tuning my printers, profiles and materials in Cura. I will keep testing in between customer print jobs.

Perhaps in 4.9.x it will revert back to whatever was working for 4.6.1

Best regards,

Mark Steele

On Mon, Nov 30, 2020 at 6:14 AM Ghostkeeper notifications@github.com wrote:

We can't really help you with print quality issues. Each print quality issue can have hundreds of causes. We've made thousands of changes between 4.6 and 4.8. We're unable to reproduce those print quality issues on our own printers with our own filaments and so we're unable to verify whether we fixed them if we make any new changes.

From your results I can't tell what Cura is really doing wrong here. Is there something unexpected in the g-code output of Cura? Are there any settings that you think should be changed in the defaults for your printer+nozzle+material+quality?

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/Ultimaker/Cura/issues/8839#issuecomment-735721905, or unsubscribe https://github.com/notifications/unsubscribe-auth/ABRMUYPPIX7JIS2DSLT647LSSN5APANCNFSM4UEHZRMA .

[Ghostkeeper]

When you printed the file using the 4.8.0 profile I supplied on your printer, what were the results? Did you also see the pattern in the perimeter that I showed in my pictures?

I didn't print it. The settings used for the Sovol SV01 don't work on my printer. For one my printer has a Bowden tube and 2.85mm filament. And your layer height is not achievable in my printer. So anything I test will most likely end in either spaghetti or terrible print quality.

You had previously reported an issue with the wall overlap compensation sometimes being on one side and sometimes on the other. I don't really see how that could cause ringing, but that is at least something that is demonstrable in Cura's output without needing your printer. However the compensation is very consistent when I try to reproduce that on my side:

So really, I don't know how I can help you. Other than by giving general printing advice, but my job is to develop Cura, not to help people with printing advice. Still, one thing you could look at is to change the infill pattern. Periodic banding like this is sometimes caused by having an infill pattern that is periodic in the Z direction. Instead, using an infill pattern that is consistent in the Z direction (like Triangle) could help.

[msteele999]

Thank you,

I truly am not looking for printing advice - I fully understand that is not your role. My hopes were that something would jump out and you would say 'Dude! turn off THAT setting there' and it would fix it.

I have tried changing the infill type, density and many settings. Even taking it down to 5 % infill or putting it to 75% infile make no difference.

I'm looking now at the defaults that Cura uses when the printer is added, vs. the ones that are added when I added the printer as an Ender CR-5 in 4.6.1 - maybe something in the settings there will lead me home.

For the time being, I run customer prints on 4.6.1 and experiment on 4.8.0

• If I find the fix, I'll report it back to you.

Best regards,

On Tue, Dec 1, 2020 at 9:52 AM Ghostkeeper notifications@github.com wrote:

When you printed the file using the 4.8.0 profile I supplied on your printer, what were the results? Did you also see the pattern in the perimeter that I showed in my pictures?

I didn't print it. The settings used for the Sovol SV01 don't work on my printer. For one my printer has a Bowden tube and 2.85mm filament. And your layer height is not achievable in my printer. So anything I test will most likely end in either spaghetti or terrible print quality.

You had previously reported an issue with the wall overlap compensation sometimes being on one side and sometimes on the other. I don't really see how that could cause ringing, but moreover the compensation is very consistent when I try to reproduce that on my side: [image: image] https://user-images.githubusercontent.com/2448634/100755401-6e413e00-33ec-11eb-9a9c-e0fad598a0e7.png

So really, I don't know how I can help you. Other than by giving general printing advice, but my job is to develop Cura, not to help people with printing advice. Still, one thing you could look at is to change the infill pattern. Periodic banding like this is sometimes caused by having an infill pattern that is periodic in the Z direction. Instead, using an infill pattern that is consistent in the Z direction (like Triangle) could help.

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/Ultimaker/Cura/issues/8839#issuecomment-736602426, or unsubscribe https://github.com/notifications/unsubscribe-auth/ABRMUYLRK6XEQNSJHCVJ6SDSST7KTANCNFSM4UEHZRMA .

[kiss81]

I share the same issues with 4.8. I can try what I want but I have the same issues (even worse actually). I tried imported, default profiles, lowered resolution but nothing helps. 4.6.2. works fine for me, so I kind of accepted to use that for now. By the way on what printer firmware are you running / version? I am on Marlin 2.0.7.2.

[msteele999]

Question - are you using OcotPrint by any chance?

I have recently jettisoned OctoPrint and started printing straight from the SD card.

In addition, I started with a stock 4.8.0 profile and made minor tweaks (# of walls, infill type / density, combing and edge hiding) and have had much better results. I will be testing the print in question later this afternoon, but my preliminary results are starting with a stock profile and making minor changes (but not touching resolution / width settings) in combination with going to an SD card only solution, are very encouraging.

I'll post images later tonight.

On Fri, Dec 4, 2020 at 8:51 AM kiss81 notifications@github.com wrote:

I share the same issues with 4.8. I can try what I want but I have the same issues (even worse actually). I tried imported, default profiles, lowered resolution but nothing helps. 4.6.2. works fine for me, so I kind of accepted to use that for now.

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/Ultimaker/Cura/issues/8839#issuecomment-738794892, or unsubscribe https://github.com/notifications/unsubscribe-auth/ABRMUYJ5RZV4XDLIQDO6KT3STDSN5ANCNFSM4UEHZRMA .

[kiss81]

No I print from the SD card. I print on a modified cr-10v2 (0.9deg stepper motors and hemera direct drive). I am using cura 4.8 on ubuntu by the way, I can give it a try on windows. The stock profiles from 4.6.2 print quite decent for me. I only need to change the usual "suspects" like temperatures and retraction distance / speed. I was hoping there was a nightly build available or something of 4.8.x / 4.9 so I can give that a try.

[kiss81]

I have to get back on my previous comment: I am now printing with a default 0.20 preset and clean 4.8 installation on a windows machine. All seems to be fine. So it's somehow an issue with the linux build for me or it's messing up my profiles somehow. I will now try to export my windows 4.8 profile and import that one into my linux build to see how that goes...

[Ghostkeeper]

How did your print pan out with the Maximum Resolution and Maximum Deviation reset to defaults, @msteele999?

[msteele999]

So - I have finally figured out what is happening.

Believe it or not, that is the z-seam.

I selected Sharpest Corner, Smart hiding. Apparently in 4.8.0, it moves the z-seam every dozen or so layers. I never considered this to be the issue as in 4.6.1, the z-seam always stayed in the same spot.

If I have Cura 4.8.0 run thru the motion of the head on each layer via preview, I see it move from the rear sharp corner (where it should be) to the front of the model, where you see it in my pictures. After some layers, it moves back. So I think this issue should be re-classified as 'Cura does not keep z-seam placed at the same location when Sharpest Corner, Smart Hiding is used.

The geometry of the model is the same on every layer, so the sharpest corner is not moving - the z-seam should stay where it started.

Thoughts?

On Tue, Dec 8, 2020 at 5:58 AM Ghostkeeper notifications@github.com wrote:

How did your print pan out with the Maximum Resolution and Maximum Deviation reset to defaults, @msteele999 https://github.com/msteele999?

— You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub https://github.com/Ultimaker/Cura/issues/8839#issuecomment-740548730, or unsubscribe https://github.com/notifications/unsubscribe-auth/ABRMUYM7IGQFUNT4RPZVFCTSTYBG7ANCNFSM4UEHZRMA .

[nallath]

It's one of those unintentional changes caused by something else. By changing the way that the simplify works, it changes the type of lines that end up in the model. Since the lines are different, it's also possible that it changes the decision where it places the z-seam (eg; same strategy, different input can result in a different outcome)

[msteele999]

So would this be considered a bug or is this an opportunity for a new feature: 'force z-seam to be in the same spot no matter what'?

Honestly, I'd love the ability to click on a spot on the model and say 'put the z seam RIGHT there'

On Tue, Dec 8, 2020 at 8:13 AM Jaime van Kessel notifications@github.com wrote:

It's one of those unintentional changes caused by something else. By changing the way that the simplify works, it changes the type of lines that end up in the model. Since the lines are different, it's also possible that it changes the decision where it places the z-seam (eg; same strategy, different input can result in a different outcome)

— You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub https://github.com/Ultimaker/Cura/issues/8839#issuecomment-740611333, or unsubscribe https://github.com/notifications/unsubscribe-auth/ABRMUYMLAEM5HFNDC5BE2F3STYQ7VANCNFSM4UEHZRMA .

[nallath]

That's already there: Set the "Z Seam Alignment" to "user specified"

[msteele999]

Jaime,

OK - how about this then - put a visual queue in the preview of the seam overlaying the entire model - don't make me go layer by layer to see where it starts. Put a blinky marquee style line (just kidding) that shows where the layer starts

On Tue, Dec 8, 2020 at 9:39 AM Jaime van Kessel notifications@github.com wrote:

That's already there: Set the "Z Seam Alignment" to "user specified"

— You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub https://github.com/Ultimaker/Cura/issues/8839#issuecomment-740658749, or unsubscribe https://github.com/notifications/unsubscribe-auth/ABRMUYKBP26GZDLGLETAK63STY3CLANCNFSM4UEHZRMA .

[Ghostkeeper]

As an aside, it's not just where the layer starts but where the contour starts. It should really just be called "seam" rather than "z seam".

We have a pull request that implements something like this: https://github.com/Ultimaker/Cura/pull/8599

[msteele999]

Thank you for the link. This seems (no pun intended) like what I am looking for. I'll follow that issue closely.

Best regards,

Mark.

On Wed, Dec 9, 2020, 06:30 Ghostkeeper notifications@github.com wrote:

As an aside, it's not just where the layer starts but where the contour starts. It should really just be called "seam" rather than "z seam".

We have a pull request that implements something like this: #8599 https://github.com/Ultimaker/Cura/pull/8599

— You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub https://github.com/Ultimaker/Cura/issues/8839#issuecomment-741712996, or unsubscribe https://github.com/notifications/unsubscribe-auth/ABRMUYJG4GBTQ4QMCHLTD33ST5NVHANCNFSM4UEHZRMA .

[GregValiant]

Is this still an issue in current Cura versions (5.8.0 and up)? Can this be closed?