Slicing problems

[bbuild 0]

Hi, I designed and have made many of these:

http://www.thingiverse.com/thing:108883

unfortunately after upgrading to an UM2 and thus getting round to installing Cura 14, the slicing now fails whereas it was working fine in versions of 13 (at least). Slicing completely misses some internal voids and fills them in (there are supposed to be 10 cubic voids at angles connecting to the five sides of this shape).

Is this controllable somehow, or is it likely to be a bug. I have other shapes that I used to be able to make fine, but now no longer work.

 

[IRobertI 520]

Try going into the expert settings and uncheck any "Fix horrible" check boxes and see how that goes.

 

[gr5 2,192]

It's fine to have cubic voids, but not double walls. Try robert's suggestion first, then look at the part in "xray" view. Any red areas are a problem. They are generated by passing a 3D line through the model and counting how many polygons it passes through. Even polygons are shades of blue and white. Odd polygons are shades of red. Red indicates an internal wall that doesn't have meaning or a hole in an intended wall.

If you have no red zones then unchecking all the "fix horrible" boxes should result in a perfect part. The exception is if you have to vertexes very close together (less than maybe .2mm). When Cura slices a layer it interesects a plane with your polygons (which are unordered in an STL file). Then it has a bunch of lines. It tries to figure out which lines intersect and tries to create loops of lines and assigns those together to be a "surface" but sometimes it gets confused if 3 or more vertexes are very close together.

Also STL files have an indication of the polygons which side is "inside" and which side is "outside". You can tell Cura to ignore that with one of the "fix horrible" settings.