Problem with spiraling (vase mode)

[Frank5300 0]

Hi,

 I found a little problem with Cura 3.2.1. When I want to spiral objects, there are always ugly spots (for example small ledges and edges). These are already created when slicing (see pictures). It does not matter how I set the slicing tolerance. The stl also looks clean (https://www.thingiverse.com/thing:124175). Is there a way to avoid that, or is it a bug?

 

best regards

Frank

[burtoogle 515]

Hi @Frank5300, have you actually tried printing this and seen flaws in the printed part?

 

I ask because when using spiralization, the layer view does show some artifacts that normally do not appear on the printed object. If there really are those artifacts on the printed part, please make the gcode available so I can check it. Thanks.

[Frank5300 0]

Hi @smartavionics, the printed part has also the flaws. For me, it looks like this occurs when changing layers (in gcode).

D_Vase_3_plein.gcode

D_Vase_3_plein1.gcode

[burtoogle 515]

I cannot see a problem with the gcode that has the smoothing enabled. The gcode that does not have the smoothing enabled has an obvious z-seam which is what I would expect. Did you print the version with smoothing enabled and see flaws? I find that hard to believe as the smoothing works well. I have sliced the stl and it looks good. I will print one tomorrow and see if there are any flaws.

[Frank5300 0]

Ok that sounds good. Unfortunately, I do not remember exactly which of the two variants I printed. Tomorrow I could again print the variant with the smoothing, to be sure.

[burtoogle 515]

I am currently printing one, will let you know how it turns out (looking good so far).

[burtoogle 515]

It came out with no visible z-seam - rather nice in transparent PETG

 

[Frank5300 0]

Cool, that's exactly what it should look like. Tonight I will repeat the 3d printing with smoothing and report on it.

[burtoogle 515]

I put water in it and it doesn't leak at all so all I need now are some daffs to go in it!

 

BTW, my settings were: 0.6mm line width, 0.2mm layers, no fan, 50mm/S print speed and 6 bottom layers.

[Frank5300 0]

So, I've also printed the vase again. To put it in the famous words, "Houston, we've had a problem ..."
Here is a picture and the corresponding code. It is printed in white PLA with fan at 30mm/s (0.4mm nozzle, 0.2mm layers, 0.4mm line width, 3 bottom layers, with smoothing).

D_Vase_3_plein_x.gcode

[burtoogle 515]

Hmm, well I can't explain that. I have looked at your gcode with 2 viewers (s3d and craftware) and can see no flaws where the z-seam runs. Looking at the gcode text, on every layer change it fiddles with the acceleration. I don't see why that should cause the problem you are seeing but it may be worth not making that change to the acceleration just in case it's having a weird effect. I can assure you that I have printed that same model today with zero flaws so I don't think there is a general problem with the spiralization but, obviously, it's not coming out right for you. BTW what happened in the middle, did you change the filament?

[Frank5300 0]

I'm just printing the vase again, but I commented out the M204 commands in the gcode. So far (51mm height) I have no artifacts. Looking more closely at the gcode, it has also been noticed that there is a G0 command at significantly higher speeds in irregular z-distances. Why?

I do not know why that looks so funny in the middle. He drove very jerky in this section.

 

The finished print without changes in acceleration.

Edited April 10, 2018 by Frank5300
Attachment of the finished print.

[Torgeir 250]

Hi Frank5300,

 

When I looked at your sliced vase using the monitor in Cura 3.2.1., I can see small hole (triangles) rotating around your vase.

If I used S3D, your vase look really nice..

Here is a picture:

 

I downloaded the .stl file for this vase and sliced using cura 3.2.1 and there was no issues, it looked very nice. Maybe there is some setting in cura that is creating this problem.

 

Anyway, good luck.

 

Thanks

 

Torgeir.

Edited April 10, 2018 by Torgeir

[burtoogle 515]

Hi @Torgeir, yes, loading the STL file into Cura does show those wacky holes but they really aren't there. They are caused by some deficiency in the gcode reader/visualisation in Cura. You can look at exactly the same gcode in other viewers (I have used s3d and craftware) and those holes are not present.

[burtoogle 515]

@Frank5300, those G0 lines that occur at the end of some of the layers are travel moves and you will see that they are actually moving a very small distance. I can't remember right now where they are coming from in Cura but they are probably harmless.

[Frank5300 0]

@smartavionics, i thing the combination of acceleration changes and speed changes is problematic for my printer (Anycubic Kossel linear plus). I will turn off the acceleration control in future. I regard my problem as solved.

[burtoogle 515]

Hi Frank, understood.

 

BTW, I have submitted a fix for the holes that are shown when the gcode is loaded back into Cura (it's https://github.com/Ultimaker/Cura/pull/3650 if you are interested).

[Torgeir 250]

 

Hi @smartavionics,

 

Thanks for this information and the link to the fix.

 

Regards

 

Torgeir.

 

 

[Frank5300 0]

Hi, I have to comment on my problem again. It is probably not changing acceleration which bothers but the connection between computer and printer. Maybe the Usb / Com3 interface is too slow. When I print from the SD card (like the last vase) I get significantly better results at all.

[burtoogle 515]

That's weird, why should printing using the USB cause flaws to appear where the z-seam runs? Personally, I don't print using USB as I have seen quality issues before caused by lag in the USB data stream.

[Frank5300 0]

1 hour ago, smartavionics said:

I don't print using USB as I have seen quality issues before caused by lag in the USB data stream

Maybe the lags are the cause of flaws.

[Torgeir 250]

I'll say. right you are...

 

Take care.

 

Good luck.

 

Thanks.

 

Torgeir.