Problem with spiralize in CURA 3.6

[Kefon 0]

Hi everyone! I'm having a weird behavior with CURA 3.6 and spiralize (vase mode).

Some layers are missing, replaced by a straight line... (see the pictures)

I'm using a very classic profile, execpt for the spiralize outer contour mode.

 

CURA 3.6

--> Layer display shows some missing or partially missing layers

--> If I print like this, yes, the problem is visible in the part

--> If I move down the part in CURA to print only the top of my piece, to make a quick test on where the problem is, well, no more problem displayed in CURA and the print is ok, the problem disappear! (but it reappears as soon as I try to print the whole part)

 

CURA 3.4.1

--> No problem at all!! (with the exact same profile)

After looking everything, I wanted to try other older versions to see where the problem is, and check if the problem comes from CURA 3.6 or my STL. CURA 3.5 and 3.5.1 have the same problem, but with CURA 3.4.1, no problem at all, all my layers are here!

 

Does anyone have any idea about this problem? Is it a known bug?

Thanks in advance for your answers!

[burtoogle 513]

Hello @Kefon, please could you save the project file and attach to this thread so I can check for myself what is happening. Thanks.

[kmanstudios 1,120]

I have seen this happen periodically in regular slices too. It seems to be a sporadic issue that is not persistent. If I slice again, it goes away. I have not tried to print one, but seems to be more of a graphics issue and not a real slice problem.

[DidierKlein 729]

The user said (on facebook) he tried to print and the missing lines where indeed missing. Also with another model it doesn't happen, so it seems to be more model specific

[kmanstudios 1,120]

Waaaaayyyy, back in the day, during the 3D rendering dark ages, if an object was in one location, it would generate a black spot. If the model was moved just ever so slightly, or even the camera, it would go away.

 

Just for funzies, I wonder if it would remain if moved. Basically, a null return based on a positional issue.

[Kefon 0]

18 minutes ago, kmanstudios said:

I have seen this happen periodically in regular slices too. It seems to be a sporadic issue that is not persistent. If I slice again, it goes away. I have not tried to print one, but seems to be more of a graphics issue and not a real slice problem.

 

Well, this is not a graphic issue as I tried to print it (as mentionned by @DidierKlein) and the problems are "real" and appeared on the printed part. I tried to sliced it again, and the problem is still there, at the exact same position.

 

BUT! I discovered one more clue to this problem. I was scaling the part (not uniform).

I tried different scale to see where the problem occurs :

100% scale (uniform) -> no problem

70% scale (uniform) -> no problem

80% (XY) / 63% (Z) (not uniform) -> no problem

73% (XY) / 63% (Z) (not uniform) -> no problem

74% (XY) / 63% (Z) (not uniform) -> !!! problem !!!

 

So I tried different not uniform scalling, and some show the problem, and some not.

I have no clue on why or why not. but at least I can remove the problem by just changing a bit the scaling.

So for now I solved my problem, but this weird behavoir still exists 😉

 

@smartavionics the piece is part of a work in progress for an art piece, so I can't publish it on the forum...

I just send you a PM.

 

Thanks everybody!

 

 

 

 

[Kefon 0]

@kmanstudios I tried moved the part on different spots, the problem is still there,

but as mentionned in my previous answer, the problem is maybe coming from scaling 😉

[burtoogle 513]

Hi @Kefon, I briefly looked at your project. Yes, it does have that weird missing layer with the straight line. I set the experimental setting called Slicing Tolerance to Inclusive and it appears to slice OK (layer view looks OK, haven't actually looked at the gcode yet). So I wonder if there is something in the model that doesn't get converted into Cura's internal representation correctly? Will play with it some more later or tomorrow. Hope this helps.

[Kefon 0]

@smartavionics I just tried the Inclusive on Slicing Tolerance, you are right, it's better, but still some problems on some layers. But good to know! I never tried this option. Thank you for trying 🙂

[burtoogle 513]

1 minute ago, Kefon said:

@smartavionics I just tried the Inclusive on Slicing Tolerance, you are right, it's better, but still some problems on some layers. But good to know! I never tried this option. Thank you for trying 🙂

 

I am using my own version of Cura which has some fixes to the spiralisation which haven't made it into Ultimaker's Cura yet so you may be seeing a problem that I have already fixed. If you want you can try one of my releases which I have mentioned many times on this forum.

[burtoogle 513]

My releases are to be found at https://www.dropbox.com/sh/s43vqzmi4d2bqe2/AAADdYdSu9iwcKa0Knqgurm4a?dl=0

[Kefon 0]

@smartavionics Thx! I will give it a try tomorrow

[burtoogle 513]

BTW, @Kefon, Cura mesh tools plugin says that your nice model is not watertight so I think that maybe explains why you get that weird missing line. Also, if you look at the model in a viewer, you can see there is something weird in the area that has the missing line. You can see it here about 1/2 way up this image there are some darker segments...