STL generator for breakaway stacks

generate.py

#!/usr/bin/env -S uv run --script
# /// script
# dependencies = ["numpy-stl"]
# ///

"""
This script is for creating stacks of more-or-less flat meshes that have
symmetrical top and bottom faces (e.g. Multiboard). The gap (default 0.2mm)
should be set to your slicer's layer height. The resulting file should be
printed with 3 walls, 15% infill, with ironing of all top surfaces enabled.
"""

# stdlib
from sys import argv
# 3rd party
from stl import mesh
from numpy import concatenate

args = len(argv) - 1

# get file, count, gap from args
m = mesh.Mesh.from_file(argv[1] if args >= 1 else "mesh.stl")
count = int(argv[2] if args >= 2 else 4)
gap = float(argv[3] if args >= 3 else 0.2)

# get height of mesh
height = m.z.max() - m.z.min()
# clone mesh
meshes = [mesh.Mesh(m.data.copy()) for _ in range(count)]

# apply z-offset for meshes, including separator gap
for i, mesh_copy in enumerate(meshes):
    mesh_copy.translate([0, 0, i * (height + gap)])

# output stacked STL
combined = mesh.Mesh(concatenate([m.data for m in meshes]))
combined.save("stacked.stl")