nozzle u-turn / invisible wall bounce

[boogieman 1]

Cura 3.6 (and maybe earlier also) has a strange behaviour. It changes the direction of the wall in situations where it is completely unnecessary or even detrimental.

There is a simple test object on thingiverse:
https://www.thingiverse.com/thing:3439448

It is like it would bounce of an invisible barrier and change the direction, which causes an ugly seam. Continuing in the same direction would absolutely be possible in this case. Slic3r for example does exactly that.

No settings in Cura seem to influence it. Does anyone have how to change this behaviour?

 

[burtoogle 516]

Helllo @boogieman, please save the project (.3mf) for that print and attach to this thread so I can look at the settings you are using. Thanks.

[boogieman 1]

Hi @smartavionics, here are my settings.

CFFFP_ring_255_16.3mf

[burtoogle 516]

Thanks for the file. I see what you are saying. Well, that's the normal Cura behaviour. It always prints a part's outside walls in a CCW direction and prints the walls for the part's holes in a CW direction. There's nothing you can do to change that. The slicer could be changed to print all walls in the same direction and this has been discussed recently elsewhere. For most parts it doesn't make any difference but I can see for parts that have no infill between the outer walls and the walls around a single hole (i.e. a tube like your example) it would make sense to print all the walls in the same direction.

Edited February 19, 2019 by burtoogle

[nallath 1,125]

It's something we're already looking into.