Spiralize Contour Weirdness

[Nicolinux 288]

Hi,

I wanted to print this object (link) and decided to do a few test runs with a scaled down version. I activated the "spiralize contour" setting because the object looks almost like a lamp.

The thing is, with this setting on the printed object exhibited the same artifacts that one would identify as banding:

The weird thing though - gcode preview in Repetier Host showed it as well!

As soon as I deactivated spiralize contour the object printed fine.

Well not fine because on one object the printer decided to underxtrude just one layer... (I printed two at once, one after another).

So my question is, how can this happen? I may need to rethink my whole "wobble banding" issue because it seems that under some circumstances this artifacts are added by Cura.

 

[gr5 2,071]

As I understand it, sprialize *only* works properly for an object where every slice is a single closed polygon. So this works great for vases and cups. Also it will only do a single pass on this polygon wall so if you ask for a .8mm wide wall and you have a .4mm nozzle it will be basically extruding at 200% flow. Also it will not print a top.

The part you show here - if you slice it is more like to curve segments that don't meet. It is nothing like a polygon.

Another rule of thumb: spiralize and retraction should never occur on the same part.

 

[Daid 304]

Spiralize contains a bug if comes across multiple islands. I've fixed it for the next release, so that might be your troublemaker here.

 

[Nicolinux 288]

Ok, thanks for the info. I'll test this corner case scenario with the next version.