I setup up SLAcer.js with a 1920x1080 pixel resolution at 192mm x 108mm, and then imported the STL model. SLAcer.js laid out the model with the long part of the object along the X axis and the shortest axis up the Z axis. This is also the way that I laid out the model in Creation Workshop when I printed it previously.

The model seems to preview okay, but when I go to slice, it only makes it up to around layer 28 and then the window (in Google Chrome) hangs and I start to receive unresponsive page warnings from Chrome.

Diffuser_Molds.zip

• The window slowdown problem is fixed (f1b78f6) (too many geometries without faces).
• But Netfabb told that your files have errors. I think Creation Workshop has an auto repair tools.

For now I leave the issue open.
Thank you for the contribution.

There is a definite improvement, I am able to slice to completion now. However, you are right, there is something wrong with the triangles on this model. Let me generate the lattice a different way using Autodesk's new tooking and see how that works.

This one isn't lattice filled, but I'm also having some trouble with this calibration part:

https://github.com/CreativeTools/3DBenchy/raw/master/Single-part/3DBenchy.stl

There appear to be no non-manifold edges and vertices, but slices 75 and 80 contain triangular portions missing.

Indeed, it is a bug. I need to investigate.

I started to refactor all the code, but meanwhile a real fix an solution is to scale up or down a little bit (+/- 0.001 seems to work).