Parametric rectangular array of cavities slicing to single perimeters. Workaround for github request for more efficient slicing of array of square cavities

Responding to https://github.com/prusa3d/PrusaSlicer/issues/12481

This model takes the repeating elements of a rectangular grid and introduces small gaps to shepherd the slicer into following a single contour overall. This is a common practice in making vase mode prints of complex shapes, for example in designing printed aircraft. A square grid offers an opportunity to make a regular structure that is relatively simple to scale.

The gaps are smaller than the default gap closing dimension in the slicer, so change it from 0.049 (or whatever it is in yours) to something like 0.001. Not zero, because the model arrives in abutting chunks.

The result of this process works in vase mode, but it is not faster, and has a less uniform top layer. I've included a 3mf file for printing what the github poster needs; a 16x16 10mm grid of 2.5mm deep 9m cavities on a 0.54mm base.

The pattern is readily scaleable by placing the corners and introducing the right number of copies of the four edge. I've included the Fusion 360 file I made it with. It starts with a 3x3 sketch of the corners and repeating elements. It generates that sketch and a bigger array according to a set of parameters as shown here:

“tiny_gap” is set to 0.5mm to make it clearly visible. In use, it should be something link 0.01mm. It then scales the extruded tiles as follows, making selections and creating rectangular patterns from bodies that are the same entity regardless of the width_count and depth_count parameters:

(* ACTION: I'll substitute in unit_width and unit_depth parameters to give rectangular rather than square cavities when I get a chance. It should be obvious where those live. *)

Users of other CAD packages should have an easy time transcribing the sketch and patterning process. If you're in something like Blender and need to work with the stl file, you're in charge of scaling the group and moving faces to create the dimensions you want. Good luck!