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What is Gridfinity?

Gridfinity is an open-source modular storage system created by Zack Freedman. It provides a standardized grid-based system for organizing workspace items using 3D-printable bins and baseplates. The system uses a consistent cell-based grid where bins snap into baseplates, creating a flexible and reconfigurable storage solution for makers, electronics enthusiasts, and workshop organization.
This implementation follows the official Gridfinity specification with precise dimensions for 3D printing.

Official Dimensions

All Gridfinity bins and baseplates follow these standardized dimensions:
DimensionValueDescription
Cell size42 x 42 mmBase grid unit size
Height unit7 mmVertical measurement unit (“u”)
Tolerance0.5 mmTotal clearance (0.25 mm per side)
Bin corner radius3.75 mmStandard rounded corners
Base corner radius4.0 mmCorner radius for base profile
Base height4.75 mmTotal height of base profile
Wall thickness1.2 mmDefault bin wall thickness
Bottom thickness0.8 mmDefault bin floor thickness
Stacking lip4.4 mmHeight of stacking lip feature
Baseplate height6.4 mmStandard baseplate thickness

Key Measurements

Cell Size

The fundamental building block of Gridfinity is the 42mm x 42mm cell. All bins are measured in grid units:
  • A 1x1 bin occupies one cell (42mm x 42mm)
  • A 2x3 bin occupies 6 cells (84mm x 126mm)
  • Multi-cell bins maintain 42mm spacing between cell centers

Height Units

Bin height is measured in 7mm units (abbreviated as “u”):
  • 1u = 7mm tall
  • 3u = 21mm tall
  • 6u = 42mm tall
The base profile adds an additional 4.75mm, so a 3u bin has a total height of 25.75mm (4.75mm base + 21mm body).

Tolerance

A 0.5mm tolerance is applied to ensure proper fit:
  • Actual bin size = (cells × 42mm) - 0.5mm
  • This provides 0.25mm clearance on each side
  • Prevents binding when inserting bins into baseplates
  • Allows for slight printer dimensional variations

Base Profile

The Gridfinity base profile is a 5-layer stepped Z-profile that provides:
  • Interlocking with baseplate sockets
  • Alignment to the grid
  • Stability to prevent shifting
The base profile includes:
  • Stepped chamfers for precise alignment
  • Per-cell geometry for multi-cell bins
  • Corner radius matching for smooth edges
Total base height: 4.75mm

Features

Magnet Holes

  • Diameter: 6mm (with 0.5mm clearance = 6.5mm actual)
  • Depth: 2mm (with 0.4mm clearance = 2.4mm actual)
  • Inset: 4.8mm from cell center
  • Quantity: 4 per cell unit (one at each corner)
  • Purpose: Hold 6x2mm neodymium magnets for secure attachment to steel baseplates

Screw Holes

  • Thread: M3 metric screw
  • Diameter: 3.2mm clearance hole
  • Depth: Through base (4.75mm)
  • Quantity: 4 per cell unit (one at each corner)
  • Purpose: Secure attachment to wooden or non-magnetic baseplates

Inter-Cell Gap

Multi-cell bins have a small gap between cell units:
  • Gap: 0.5mm
  • Purpose: Allows independent cell base profiles to print cleanly
  • Bridged by upper slab for structural integrity

Tolerances and Printing

For successful 3D printing:
  • Use 0.2mm layer height or finer for base profile detail
  • Calibrate your printer for accurate dimensional output
  • The 0.5mm tolerance accommodates typical FDM printer variations
  • Corner radii ensure smooth surface finish and prevent sharp edges
  • Wall thickness (1.2mm) works with 0.4mm nozzles (3 perimeters)
All dimensions in this specification are taken directly from the GF constants object in src/gridfinity/constants.ts:1-29.

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