Gridfium is a modular storage system on a 25 mm square grid. Each cell has a stepped profile interface: base plates provide recessed sockets, and compatible objects expose a matching base profile underneath.
Horizontal size is expressed as a footprint (for example 2 × 3); vertical size is expressed in millimeters.
This document defines the interface dimensions and naming conventions used in Gridfium. Use them when building objects, adapters, or tooling so that the models fit the system and stay interchangeable with official ones.
A base plate exposes one socket per occupied cell — a recessed, stair-stepped profile cut into the plate surface. A compatible object carries the inverse geometry as its base profile (one leg per cell), which seats into the socket with a small clearance gap.
The profile is a three-step filleted prism: outer, middle, and inner rings with decreasing corner radii. Multi-cell objects repeat one leg at each cell center; the outer perimeter receives the clearance offset.
| Measurement | Value | Notes |
|---|---|---|
| Cell pitch | 25 mm | Center-to-center spacing |
| Outer clearance (C) | 0.2 mm | 0.1 mm per side |
| Profile height | 5 mm | D₀ + D₁ + D₂ |
| Outer step (D₀) | 2 mm | First stair-step depth |
| Middle step (D₁) | 2 mm | Second stair-step depth |
| Inner step (D₂) | 1 mm | Third stair-step depth |
Footprint sizing. Nominal span is columns × 25 mm by rows × 25 mm. Object outer width and depth each subtract 0.2 mm total clearance from that nominal size.
Example: a 2 × 3 object is 50 × 75 mm nominally and 49.8 × 74.8 mm at its outer walls.
The three-step profile uses filleted corners at each stair step. On a base plate (socket), the radii are:
| Measurement | Value | Notes |
|---|---|---|
| Outer fillet (R₀) | 5 mm | Outermost profile corner |
| Middle fillet (R₁) | 3 mm | After first step inset |
| Inner fillet (R₂) | 2 mm | Innermost profile corner |
On a compatible object's base profile, each radius is reduced by 0.5 × clearance so the leg fits the socket with the clearance gap — 4.9 mm, 2.9 mm, and 1.9 mm respectively.
Height is measured from the logical bottom of an object, that is, excluding the bottom part that protrudes into the base plate, or into a stacking lip.
This allows for different-sized stacked objects to perfectly align vertically.
For example, 3 × 30 mm MegaTrays stacked on top of each other will measure 90 mm tall, measured from the top of the base plate. Those will align vertically with 2 × 45 mm stacked MegaTrays.
Heights are typically rounded to 10 mm steps, though custom sizes are also allowed.
Stackable objects add a stacking lip at the top: an outward top profile that mirrors the cell interface, plus an inner recess that receives the base profile of the object above.
The lip is 4 mm tall and is not included in the object's configured height. When stacking trays, the lip locates the upper object; grips on MegaTray stacking lips add small edge features (3 mm tall) that resist lateral sliding.
Objects with a label slot expose a narrow front recess sized for a sign-shaped label. The slot opening is slightly larger than the label stem to allow insertion and tolerance.
| Measurement | Value | Notes |
|---|---|---|
| Label slot width | 12.2 mm | 12 mm stem + 0.2 mm clearance |
| Label slot thickness | 1.4 mm | 1.2 mm stem + 0.2 mm clearance |
| Label slot depth | 10 mm | Front recess depth |
| Stem width | 12 mm | Matches slot width minus clearance |
| Stem depth | 4 mm | Projection into slot |
| Stem fillet | 1 mm | Bottom corners of stem |
| Plaque corner radius | 2 mm | Plaque face corners |
| Plaque thickness | 1.2 mm | Label body thickness |
| Raised text depth | 0.4 mm | Default raised lettering |
Sign-shaped labels use Comfortaa Bold for text. For raised lettering, a variable line-width wall generator (e.g. Arachne) is recommended over fixed-line-width walls, so thin strokes print reliably.