Seems unnecessary travel pattern along printed parts

[alexjx 8]

Hi all,

 

Thank you for reading this. I'm trying to understand the travel pattern of Cura. I'm using 3..6, trying to print a spring of a toy bike.

What I understood (I hope) is that cura tries to print the inner wall then infill, so it has to move around.

But, why it has to move in the pattern as if it's trying to avoid the printed parts???

And even more... it dosesn't matter if I disable the "avoid printed parts when travel" option.

 

Thanks in advance.

 

Jia

 

Additional info: This is a snapshot of the first layer.

Edited February 4, 2019 by alexjx

[sibianul 0]

Maybe the Combing is enabled, and this causes to move along the already printed parts. Just try to disable to see if it changes the TRAVEL paths.

 

https://ultimaker.com/en/resources/52507-travel

[Smithy 1,146]

With combing enabled, Cura tries to stay inside the part for travel moves, to avoid retractions. You can turn combing off or just set it to "not in skin" to avoid scratches there.

[burtoogle 516]

Looks to me that the combing has failed in the sense that the combed distance is far greater than the "as the crow flies" distance. Perhaps the combing logic should put some upper limit on the ratio of those distances and not comb if the limit is exceeded.

[alexjx 8]

Thank you all. Combing does have an impact on this. It's interesting to find out.

"Not in skin" does not work in this case, since the spiral path is "skin" after all. 

@smartavionics I agree that there should be an upper limit. I thought the "Max Comb Distance With No Retract" was the limit... but it seems it only impact the "retraction"... not the travel...😂

[burtoogle 516]

1 minute ago, alexjx said:

"Not in skin" does not work in this case, since the spiral path is "skin" after all. 

 

Is it? I can't tell from your images. Even if that spiral does contain skin areas, there is still a gap between the skin and the outline so the "not in skin" combing will travel within that gap.

[alexjx 8]

I think I used the wrong words... it works as intended. but just not my expectation. 

It does travel within the gaps. regarding this, the avoid distance doesn't seem to work.

Please see the attached image, I tried to set an ... really large distance, but it still travels within the gap.

 

 

What I expected was following, when I set to "Within Infill" or "Off".