Cura Hi-Polygon issue with organic models ?

[chrii 5]

Hello guys,

Most time my UM2 was printing more technical stuff and easy models without any issues.

I now also want to use my "old" Orca printer with Cura 2.6.2 as it finally has the features i need to print the quality and accuracy i need.

So the printer is working with Cura already and i printed my usual testparts with success so far.

Now i wanted to print also high res organic models, which i normally not do.

Therefor i wanted to print a little baby groot at 50% scale and there where the issue`s startet.

Both my Orca and the Ultimaker2 are equipped with a 0.4 Nozzle (Ollson Block on the UM2).

the first printed was with 0.15m layer height on the Orca and i was supprised that the print was full of pimple`s i normally do not have.

then i did a cross test and made the gcode with Slic3r and it was printed successfully

After looking for the issue for a couple of hours i have not found any issue also because simple parts do print fine.

so finally i printed the groot on my UM2 with original Low setting (also 0.15mm layer height).

But there the pimple`s also appear.

left = Orca with slic3r   (forgot to set the minimum layer time, thats why whe neck is so ugly). (marlin code)

middle = Orca with Cura (marlin gcode)

right = Ultimaker with Cura  (ultigcode)

After analyzing the gcode i noticed that the generated code is full with "jumped" lines.

This is the Code from Cura  (marlin gcode)

 

This is the Code from Slic3r  (marlin gcode)

At first i thought it is the stl file itself that has the issue, but then i tried a couple of other models (dragon, sculp, Elephant and most of them have the same issue.

as soon as the surface is not completely smooth the issue appears.

Afterwards i also tried Cura version 2.1.3 / 2.3.1  / 2.5 and tried a different computer with a clean installation which all gave me the same guly results.

so it this a general issue or what is wrong on my machines/software ?

Chri

Edited July 9, 2017 by Guest

[bagel-orb 61]

Thanks for this elaborate report!

I will definitively dive into this problem.

[bagel-orb 61]

What if you try to turn off Compensate Wall Overlaps?

Did you use the high detail version of Baby Groot?

[bagel-orb 61]

What gcode viewer are you using there?

[bagel-orb 61]

What material are you using?

Did you select the right material in Cura?

[bagel-orb 61]

What's your operating system?

Is it 64bit?

[chrii 5]

Hy

i`m using Craftware as Gcode viewer, it has some very nice features, maybe some of them will find a way into cura one day

i used the low-poly version with 28MB

i did a quick gcode check without the "compensate wall overlap" feature, was looking similay.

maybe i have time tomorrow to do a new testprint.

My systems are all with Windows 10 X64 as Cura 2.6.2 is only available X64.

On the UM2 i have the original silver UM-PLA, UM2 Settings at cura don`t show a material choice function.

on the ORCA i`m using the generic ABS feature, and configured it as always.

EDIT: what i noticed is that the gcode of UM is more than twice as large, maybe its just trying to print every detail of the part even the extreme tiny one`s

i know that other slicery normally don`t generate a gcode with that extreme fine details.

maybe a optional feature with reducey quality like minimum length per line, or a smoothing feature with a defined factor may help ?

sincerly Chri

Edited July 10, 2017 by Guest

[bagel-orb 61]

Hi Chri,

Cure does do some quality reduction on segments smaller than 10 micron when the removed vertex would only result in a shortcut path of 5 micron. Perhaps those parameters should be set a bit more aggressive...

You could try the ABS profile from the UM2+ - it might work better than the default profile of the UM2.

I suggest you turn off the setting Fill Small Gaps for organic models like this.

Edited July 12, 2017 by Guest

[bagel-orb 61]

PS: which features from Craftware would you like most in Cura?

[chrii 5]

Hi Chri,

Cure does do some quality reduction on segments smaller than 10 micron when the removed vertex would only result in a shortcut path of 5 micron. Perhaps those parameters should be set a bit more aggressive...

You could try the ABS profile from the UM2+ - it might work better than the default profile of the UM2.

I suggest you turn off the setting Fill Small Gaps for organic models like this.

Ok i`ll try that when i`m back at home next week

Maybe this would be a feature for the next cura versions to be able to manually be able to set that quality reduction distance.

This may also be used to print real "low poly" stuff as a type of art

PS: which features from Craftware (CW) would you like most in Cura?

i think you probably mean i like to see the most in cura from CW?

It`s definitely the whole viewer part,

* visualization is nice and good visible at CW which is most important, at cura its hard to see lines structure even with the new view.

* you can change the colortypes for a couple of different types (feedrate, speed, line type, material, extruder)

* it`s also calculation/showing the line width good, so every time when i try i new slicer or setting, i can check before printing if the extrusion and so on are set correctly.

* you can also go through the lines with a slider, not only the layers which is very cool

and while going through the lines it show`s you the text gcode to also can see where a issue has been generated.

altough CW has some issue with showing Ulticode some time, thats why i also tried out normal Marlin/reprap gcode.

most other things CW have had at the slicer over cura have been implemented into cura since the 2.x version, so i`m only using CW for gcode visualization/ analyzing.

Chri

[chrii 5]

Hello,

sorry for my late reply, i now tested a UM2+ profile including the default PLA material at the UM2 printer, and disabled your mentioned feature but the result is still the same.

Chri