Gridfinity Rebase

CLI for replacing Gridfinity bin bases with configurable presets or a base copied from another STL.

Install

Available on PyPI as gridfinity-rebase. Requires Python 3.10+.

With uv

Use uv to run the CLI without installing it permanently:

uvx gridfinity-rebase bin.stl --preset magnet-holes

Or install it as a command available from any directory:

uv tool install gridfinity-rebase
gridfinity-rebase bin.stl --preset magnet-holes

With pip

Create and activate a virtual environment, then install the package:

python -m venv .venv
source .venv/bin/activate
python -m pip install gridfinity-rebase
gridfinity-rebase bin.stl --preset magnet-holes

From source

To install a local checkout, run this command from the repository root:

uv tool install .

Usage

Important

I tested this CLI tool only on macOS machine.

Pass an STL file to replace its base. You can also use the explicit gridfinity-rebase rebase subcommand. Run gridfinity-rebase without arguments to display help.

# Create smooth bottom-loading magnet pockets in bin-rebased-magnet-holes.stl.
gridfinity-rebase bin.stl --preset magnet-holes

# Create side-loading magnet pockets in bin-rebased-rebuilt.stl.
gridfinity-rebase bin.stl --preset rebuilt

# Create screw holes without magnet pockets in bin-rebased-screws.stl.
gridfinity-rebase bin.stl --screws

# Add screw holes to bottom-loading press-fit pockets
gridfinity-rebase bin.stl --preset press-fit --screws

# Place magnet pockets and screw holes only at the four outer corners of the bin.
gridfinity-rebase bin.stl --preset rebuilt --screws --only-corners

# Add side-loading magnet pockets and an M15x1.5 thumbscrew hole.
# The output is bin-rebased-rebuilt-thumbscrew.stl.
gridfinity-rebase bin.stl --preset rebuilt --thumbscrew

# Copy a base from another bin
gridfinity-rebase bin.stl --base donor.stl -o result.stl

# Inspect a model or list presets
gridfinity-rebase inspect bin.stl
gridfinity-rebase presets

Presets

Available presets: plain, magnet-holes, rebuilt and press-fit. refined is an alias for rebuilt.

magnet-holes creates smooth bottom-loading Ø6.5 × 2.4 mm pockets without ribs. press-fit adds eight crush ribs to each pocket. You can also get this geometry with --preset magnet-holes --crush-ribs.

The previews show the same 2×3 example bin from underneath. Click a preview for the full-size image. Append the options in each row to gridfinity-rebase bin.stl.

Preview	Preset	Options
	plain creates standard feet without magnet pockets or screw holes.	--preset plain
	magnet-holes creates four Ø6.5 mm magnet pockets per foot, 2.4 mm deep, without crush ribs.	--preset magnet-holes
	rebuilt creates four pockets per foot in a fan pattern, with one opening per edge. Small underside slots let you remove magnets.	--preset rebuilt
	press-fit creates four bottom-loading pockets per foot, each with eight crush ribs.	--preset press-fit

Geometry options

The default preset is plain. Select another preset or change individual settings:

• --magnets none|side|bottom: no magnet pockets, side-loading pockets, or bottom-loading pockets.
• --side-pocket-height MM: set the side-loading pocket height. The default is 2.1 mm.
• --screws / --no-screws: enable or disable 3 mm screw bores.
• --crush-ribs / --no-crush-ribs: enable or disable ribs in bottom-loading pockets.
• --only-corners: limit magnet pockets and 3 mm screw bores to the four outer corners of the whole bin, regardless of grid size. A 1×1 bin keeps all four holes. Central --thumbscrew holes still appear in every foot.
• --thumbscrew / --no-thumbscrew: enable or disable the central threaded hole.

Examples with geometry options

Add flags to a preset to combine magnet pockets, screws and central threads, or to place magnet pockets and screw bores only at the outer corners.

Preview	Description	Options
	Each side-loading pocket has a Ø3 mm screw bore.	--preset rebuilt --screws
	Each foot has four Ø3 mm screw bores without magnet pockets.	--screws
	Bottom-loading pockets have crush ribs and screw bores in their floors.	--preset press-fit --screws
	Each foot has side-loading pockets and a central M15×1.5 threaded hole.	--preset rebuilt --thumbscrew
	The whole bin has four side-loading pockets, one at each outer corner, instead of 24.	--preset rebuilt --only-corners
	The bin has 24 side pockets, 24 screw bores and six central threaded holes.	--preset rebuilt --screws --thumbscrew
	The whole bin has four side pockets and four screw bores at its outer corners. All six feet have a central threaded hole.	--preset rebuilt --screws --thumbscrew --only-corners

Close-ups

Preview	Description	Options
	The magnet slides through the opening in the edge of the foot.	--preset rebuilt
	Insert the magnet into the circular recess from underneath.	--preset magnet-holes
	Eight ribs narrow the pocket for a press fit.	--preset press-fit
	The M15×1.5 threaded hole is 4.75 mm deep, with a solid bridge above.	--preset rebuilt --thumbscrew

The images show geometry generated by the CLI. Regenerate the graphics.

See curve resolution for --segments settings and visual comparisons.

Key details

• The CLI supports standard rectangular Gridfinity bins on a 42 mm grid. Use millimeters for STL units, with feet at the bottom and Z pointing up.
• Any rotation around Z is detected automatically, including for a separately rotated donor. Processing uses a common local frame: feet aligned with X/Y, the first foot centered at X=Y=0, and the underside at Z=0. The result returns to the input's original position and rotation. Models lying on their side or upside down are not automatically reoriented.
• The CLI detects the base and cut height. If the feet are valid Gridfinity but the full base is not recognized, it replaces only the bottom 4.75 mm foot profile and prints a warning. Geometry above the cut is preserved, including any old holes. Check these results in a slicer. Invalid meshes, incompatible seams and disconnected replacement feet still fail validation.
• A donor base can match the input grid or have its X/Y dimensions swapped. The CLI can also tile a 1×1 donor base across the input.
• Unmodified presets write to bin-rebased-PRESET.stl. --thumbscrew and --only-corners append their names to the filename. Modified settings use a descriptive suffix, such as bin-rebased-magnets-bottom-crush-ribs-screws.stl. Donor bases use bin-rebased.stl. Use -o to choose a filename and --overwrite to replace an existing output.
• JSON reports include the resolved geometry settings and a warnings array (empty when there are no warnings). With --json, warnings are included in the report instead of printed to stderr. base_height_mode is auto when the program chooses the cut height, or manual when --base-height is supplied. Automatic 4.75 mm foot replacement includes a warning. base identifies the starting preset or donor path. The default preset is plain. For donor bases, geometry is null.
• Inspection and rebase reports include rotation_z_deg, the local grid's rotation in the source coordinates, and origin_mm, its first foot's center at underside height in those same coordinates. Square feet determine rotation modulo 90°; the reported angle is in [-45°, 45°), so equivalent orientations can swap the reported grid's X/Y dimensions. Reported cut heights remain relative to the underside.
• --base-height MM overrides automatic detection for custom models and replaces everything below that height. The minimum is 4.75 mm.

Run gridfinity-rebase --help for all options.

Performance

Run the benchmark from the repository root:

uv run --locked --python 3.11 python scripts/benchmark.py --runs 5

The benchmark generates all test models locally. You do not need to download example STLs. See benchmark instructions, methodology and reference results for JSON output and environment details.

AI Disclosure

Szymon here. I used AI to build this tool.

I needed a way to quickly replace the base of custom Gridfinity bins downloaded from the Internet, but I didn't want to spend too much of my free time on this. I collaborated with the AI, describing how it should work, how I want to use it and what's the important from the both code perspective and end-user perspective. It allowed me to iterate and create something that is exactly what I needed. Now I share it with you.

Just want you to know.

License

The MIT license covers this CLI and its adapted preset implementation.

Processing a model does not replace its existing license or attribution requirements. When sharing a rebased STL, preserve applicable notices and comply with the licenses of the input model and any donor geometry.

Acknowledgements

Preset geometry is adapted from the MIT-licensed Gridfinity Rebuilt implementation by Kenneth Hodson, based on Gridfinity by Zack Freedman. Rebuilt credits Gridfinity Refined by grizzie17 as the source of its side-loading magnet pockets.

Rebuilt source files at revision 910e22d8607fd7f5f51ad5e5cbc5287a76810bfd:

• standard.scad: mating profile, grid, radii and hole dimensions.
• gridfinity-rebuilt-holes.scad: side-loading magnet pockets and crush ribs.
• base.scad: fan arrangement of the four pockets and the central threaded hole.

The native thumbscrew thread tessellation derives from ScrewThread() in threads-scad, created in 2016 — 2017 by Ryan A. Colyer and released under CC0 1.0.