Gridfinity Modular Storage System: Baseplates, Bins, and Custom Parametric Inserts

If you've printed for more than a few months you already have the problem Gridfinity was built to solve: drawers full of loose screws, drill bits, and half-organized parts bins that don't share a common footprint. Gridfinity is an open-source modular storage standard originally released by Zack Freedman that defines a 42mm grid unit for baseplates and bins, so that anything you print to the spec — whether it's your own design or one of thousands of community files — locks together and stacks predictably. It has become close to a universal organization system in the maker world precisely because the grid is public domain and the tooling to generate custom sizes is free. This guide covers the actual standard, how to print it well, and how to generate your own parametric bins instead of hunting for a pre-made STL that almost fits.

The Grid Standard

Gridfinity's base unit is a 42mm x 42mm square, referred to as "1U." Baseplates are printed or bought in multiples of that grid (a 4x4 baseplate covers 168mm x 168mm), and bins snap onto the baseplate in a friction-fit connection using small magnets, printed clips, or the default weighted-friction fit that needs no hardware at all. Bin heights are measured in 7mm increments — a "3-height" bin (21mm tall) is roughly business-card-box depth, a "6-height" bin doubles that. Because every baseplate and bin on the planet built to spec shares these dimensions, a bin designed by a stranger on Printables will drop into a baseplate you printed yourself with zero fitting.

What You Actually Need

ComponentPurposeNotes BaseplatesMount to a drawer bottom or pegboard; bins sit on topPrint flat, PLA is fine — no load-bearing stress BinsHold parts, snap to baseplate gridPETG for anything handled roughly; PLA is fine for drawer-only use Baseplate connectorsJoin multiple baseplates into a single rigid surfaceOptional but recommended for anything larger than 5x5 Magnets (6x2mm)Positive bin retention for a pull-out drawer or a mobile cartSkip these for a stationary drawer — friction fit is enough LabelsIdentify bin contents at a glanceLaser-engraved acrylic or wood tags work well if you also have a diode laser like the Ray5

Printing Baseplates and Bins Well

Baseplates are large, flat, and thin in cross-section, which makes them prone to warping on printers without a heated enclosure. A brim or a few skirt loops on the first layer, a clean PEI or textured sheet, and a well-calibrated first layer (see our first layer calibration guide) solve most of the warping you'll see, especially in PETG which shrinks more than PLA as it cools. For bins, orient them so the open top prints last with no supports needed — a properly designed Gridfinity bin is self-supporting by geometry, so if a model you downloaded needs supports on the walls, it wasn't built to spec and you should look for a different file. 0.2mm layer height with 3 walls and 15% infill is the community-standard balance of strength and print time; drop to 2 walls and 10% infill for large bulk bins where you're prioritizing speed and material over ruggedness.

Tolerances matter more here than in almost any other category of printed part, because the entire point is that bins from different sources interlock. Run a single calibration bin first and test the fit against a baseplate before batch-printing a drawer's worth — if it's too tight, check that your flow rate and E-steps are calibrated rather than immediately scaling the model, since over-extrusion is the most common cause of a bin that won't seat.

Designing Custom Bins Parametrically

Pre-made bins cover drill bits, screws, and SMD components well, but the real power of the system shows up when you need a bin sized for something odd — a specific multimeter, a coil of filament sample, a set of laser lenses. The two dominant tools for generating custom Gridfinity geometry are:

Gridfinity Generator (OpenSCAD-based, various forks) — parametric scripts where you set X/Y grid units, height units, and internal dividers as variables and re-render. This is the same workflow covered in our OpenSCAD for parametric maker projects guide, and it's the fastest path to a bin sized exactly to a tool you're holding in your hand.
Fusion 360 / Web-based generators — several browser tools (search "Gridfinity generator") let you punch in dimensions and export an STL without touching code, at the cost of less control over internal wall layout and label tabs.

For a bin with internal dividers (common for organizing different screw lengths in one drawer slot), set the divider count as its own parameter rather than modeling walls manually — most generator scripts expose an X-divider and Y-divider count that automatically recompute wall spacing so every compartment stays equal width. Add a label tab by enabling the built-in tab option in the generator rather than modeling one separately; scaled tabs that don't match the community-standard tab geometry tend to interfere with adjacent bins in the same row.

Mounting and Scaling Up

For a drawer, print flat baseplates sized to the drawer's interior and don't bother joining them — gravity and the drawer walls keep everything in place. For a pegboard, wall-mounted tool panel, or a mobile cart, print or buy baseplate connectors and join plates into a single rigid sheet, then screw or Command-strip the assembled sheet to the surface at a few points along the perimeter. If you're outfitting an entire workbench or a print farm's spool and tool storage, plan the grid size before you print anything — measure the usable footprint, divide by 42mm, and round down, since a Gridfinity layout with an awkward partial row at the edge looks worse than a slightly smaller fully-gridded area.

Where This Fits With Other Shop Organization

Gridfinity is best for small parts, tools, and consumables — it's not a replacement for the kind of heavy sheet-goods and lumber storage covered in our vertical sheet storage rack project, and it won't hold up to the loads a welded steel workbench is designed for. Where it earns its place is exactly the drawer full of loose hardware, the laser rotary attachment rollers, the spare nozzles, and the calipers that otherwise end up rattling around loose — organized once, in a system that keeps working as your inventory of tools and consumables grows.

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