Periodic, model dependent, horizontal banding in prints

[Rossboss 0]

I posted this last week: https://ultimaker.com/en/community/39012-lattice-printing-and-shell-gap In short, I am trying to print this tubular shell with an integrated lattice. The build featured in the link was done on a 0.2mm layer height and it resulted in periodic layers missing from the outer shell as seen in the pictures.

After changing the layer height to 0.1mm, this latest print in the picture below looks better but clearly still has a periodic layer issue. I'm guessing the smaller layer height did not eliminate the problem but the z increment was small enough that it no longer results in a gap, just a slight inset of the layer. I'm 100% positive it is nothing purely mechanical wrong with the UM3 (z screw, belts, axels) as this only occurs on models that have the integrated lattice similar to this one but once the lattice section is finished the shell resumes printing as it normally should. Notice in the picture below where the periodic layer issue stops in the picture and the tube starts to get thinner; this is where the lattice ends inside the tube.

While this is obviously an issue brought upon by the file, the file itself does not include any errors resembling this anomaly whatsoever and X-ray/Layer View does not reveal any holes or missing layers. This leads me to believe that this is either a software issue or a material/mechanical process issue exposed by some characteristic of the file.

Edited March 1, 2017 by Guest