stlbench 0.2.1

STL preparation toolkit for resin 3D printing: uniform scaling, bed packing, fill, autopack.

stlbench

STL preparation toolkit for resin 3D printing.

stlbench takes STL files and prepares them for SLA/DLP printers: uniform scaling to fit the build volume, packing parts onto rectangular print plates, filling the bed with copies, and combined scale-and-pack in one step. Supports are not generated -- use your slicer (Lychee, Chitubox, PrusaSlicer, etc.) after export.

Installation

pip install stlbench

For hollow shell support (optional, requires scipy):

pip install "stlbench[hollow]"

Development install

git clone https://github.com/NikitaDmitryuk/stlbench.git
cd stlbench
poetry install --with dev

Quick Start

# Inspect model parts
stlbench info -i ./parts -c configs/mars5_ultra.toml

# Scale all parts to fit the printer
stlbench scale -i ./parts -o ./scaled -c configs/mars5_ultra.toml

# Pack scaled parts onto plates
stlbench layout -i ./scaled -o ./plates -c configs/mars5_ultra.toml

# Scale + pack all on one plate in one step
stlbench autopack -i ./parts -o ./packed -c configs/mars5_ultra.toml

# Fill the bed with copies of a single part
stlbench fill -i ./part.stl -o ./filled -c configs/mars5_ultra.toml

Or specify the printer inline without a config file:

stlbench scale -i ./parts -o ./scaled -p "153.36,77.76,165"

Commands

info -- Analyze models (read-only)

stlbench info -i ./parts -c configs/mars5_ultra.toml

Displays a table with AABB dimensions, volume, vertex/face counts, whether each part fits the bed, maximum scale factor, and how many copies would fit (fill). No files are written.

scale -- Uniform scaling

stlbench scale -i ./parts -o ./out -c configs/mars5_ultra.toml

Computes a single scale factor so that every part fits inside the printer build volume. The largest part determines the factor; all parts share the same scale. Supports two methods: sorted (default) and conservative.

Key options: --dry-run, --no-upscale, --method, --orientation free, --hollow, --supports-scale.

layout -- Pack parts onto plates

stlbench layout -i ./scaled -o ./plates -c configs/mars5_ultra.toml

Arranges already-scaled STL files onto rectangular print plates using rectpack. Exports plate_01.stl + plate_01.json with positions. Multiple plates are created if parts do not fit on one.

Key options: --dry-run, --gap-mm, --algorithm shelf|rectpack.

autopack -- Scale + layout on one plate

stlbench autopack -i ./parts -o ./packed -c configs/mars5_ultra.toml

Binary-searches for the maximum scale factor at which all parts fit onto a single plate simultaneously. Combines scale and layout into one step with a different goal: all parts on one plate, not each part fitting individually.

Key options: --dry-run, --gap-mm, --margin, --supports-scale.

fill -- Maximum copies of one part

stlbench fill -i ./part.stl -o ./filled -c configs/mars5_ultra.toml

Packs as many copies of a single STL file as possible onto one plate. Useful for batch printing identical parts.

Key options: --scale (scale the part to fit before filling), --dry-run, --gap-mm.

hollow / supports

• stlbench hollow -- reminder to configure [hollow] in the TOML config and use --hollow with scale.
• stlbench supports -- reminder that supports are added in the slicer.

Configuration

Printer profiles are TOML files. See configs/mars5_ultra.toml for a complete example (ELEGOO Mars 5 Ultra).

Key sections:

Section	Purpose
[printer]	Build volume: width_mm, depth_mm, height_mm
[scaling]	bed_margin, supports_scale
[orientation]	mode (axis/free), samples, seed
[packing]	algorithm (rectpack/shelf), gap_mm, report
[hollow]	enabled, wall_thickness_mm, voxel_mm

Examples

See examples/README.md for a full walkthrough using the included Gendalf model (3 parts tracked via Git LFS).

Package Structure

Module	Purpose
stlbench.cli	Typer CLI application
stlbench.core	Scale factor computation and orientation
stlbench.config	Pydantic schema + TOML loader
stlbench.packing	Shelf and rectpack algorithms
stlbench.export	Plate STL assembly and JSON manifest
stlbench.hollow	Voxel shell hollowing (optional, scipy)
stlbench.pipeline	Command runners (scale, layout, fill, etc.)

Limitations

• Boolean and voxel operations are sensitive to non-manifold STL. For complex models use a mesh repair tool first.
• Hollow shells in this package are a simplified voxel approach; for production use your slicer's built-in hollowing.
• Supports are not generated -- always add them in your slicer.

License

MIT