Strange effect when rotating

[pinthenet]

In order to print the attached object I want to rotate it 180° around X or Y.
If I rotate round Y it's OK, but rotation around X results in 'missing' layers in the preview....screenshot attached

I am printing now but I assume it's going to get in a mess.

The object is part of a much larger one created in 3ds max, then split with netfabb then repaired in netfabb.

The process settings haven't been changed for X or Y rotation and are the ones I've used for all other split objects in the project. I also had to rotate other objects but never had an issue, and I'm certain I rotated some around X, although I think only 90°

S3D 3.0.2
Windows 10

Any ideas?

Regards
John

[zemlin]

Sometimes changing the layer thickness by a tiny amount can resolve an issue like that. I've changed from 0.2mm layers to .199 and had the slicing come up clean.

[Heutinck]

in my limited experience this is usually cause by some errors in the stl file. try running it through one of the online repair sites. Microsoft has one that works well for me. https://netfabb.azurewebsites.net/

[pinthenet]

I jsut tried 'Repair/Identify Self Interecting surfaces' in S3D and it found some. THe re hightlights are below the odd section but that may be a cause.

I'll try the online netfabb
Thanks

[pinthenet]

That was quick! The https://netfabb.azurewebsites.net/ site fixed it, thanks again.
I am using Octoprint to run the actual print and the Gcode viewer doesn't seem to miss any layers so maybe I'm lucky