Gridfinity generator

What Gridfinity is, if you are new to it

Gridfinity is a storage system designed by Zack Freedman and given away. Everything is built on a 42 mm grid and a 7 mm height step: bins sit in baseplates, baseplates tile a drawer, and a bin made by one person drops into a baseplate made by another because everybody works to the same handful of numbers.

That interoperability is the whole point, and it is also the whole risk. A generator that is a fraction of a millimetre out produces bins that bind, rattle or will not seat. So every dimension this page uses is derived from one profile written down in one place, and the socket in a baseplate and the lip on a bin are computed from that same profile rather than typed in again.

The system is public domain, which is why there are dozens of generators for it. This one exists because the others are either OpenSCAD files you have to install something to run, or web tools that send your settings to a server.

Bins

**Size in cells.** A 2×1 bin is two cells across and one deep, which comes out 83.5 mm by 41.5 mm — two 42 mm cells with the standard half millimetre of clearance taken off so it drops into a baseplate rather than jamming in it.

**Height in units.** One unit is 7 mm. Three units is a good general-purpose bin at 21 mm; six units holds tall things; one unit is a tray for flat parts. The stacking lip adds another 3.55 mm on top and is not counted in the units, which is the standard’s own convention.

**Compartments.** Two numbers, across and deep, which divide the inside into a grid. The dividers are the same thickness as the walls, and they are not drawn as walls at all — they are simply what is left between two cavities. A 2×3 bin divided 3×1 gives you three long channels; divided 1×3 gives you three wide ones.

**Wall and floor.** 1.2 mm of wall is three passes of a 0.4 mm nozzle and is what the standard assumes; the floor is a little thicker because it is what your parts sit on and what the magnet pockets are cut into. Leave the wall at 1.2 mm unless you have a reason: it is the number that makes the stacking lip leave exactly the right opening, so bins above sit exactly on the 7 mm steps.

Baseplates

A baseplate is a tile of sockets that a drawer or a shelf gets lined with. Switch to it with the button at the top and set how many cells across and deep you want.

The sockets go right through the plate rather than being blind pockets. That is deliberate and it is what makes a baseplate quick and cheap to print: it lies flat on the bed, needs no supports at all, and a 3×2 plate uses about nine cubic centimetres of plastic.

A baseplate is full 42 mm cells with no clearance taken off. The clearance lives in the bin, which is why a bin is 41.5 mm rather than 42. Taking it off both would give you bins that rattle.

For a large drawer, print several small plates rather than one big one. They tile perfectly, they fit on any bed, and a failed print costs you one tile instead of six hours.

Magnets and screws

Four pockets under every cell, sized for the 6 × 2 mm discs the system was designed around and that every Gridfinity parts list sells. The pockets are a fraction wider than the magnets so one can be pushed in rather than hammered.

Glue them. A press fit alone works loose after a few dozen removals, and a magnet that falls out inside a drawer is worse than no magnet. A drop of superglue or two-part epoxy in each pocket is enough.

Screw holes are the alternative, in the same four positions, sized as M3 clearance. Use these when the bin has to be fixed down permanently — in a toolbox that gets carried, or on a wall. You cannot have both at once, because they occupy the same space.

Either way, check the floor is thick enough. A 2.4 mm magnet pocket under a 1.2 mm floor leaves nothing between the magnet and your parts, so the floor is raised to 1.6 mm by default and the tool tells you if what you have asked for will not fit.

Printing these well

No supports, for either bins or baseplates. Everything here is designed to print standing on the bed with no overhang steeper than 45 degrees, which is most of why the foot profile looks the way it does.

Three walls and about 15% infill is plenty for a bin — they hold small parts, not loads. A baseplate wants a few more top and bottom layers because it is mostly flat surface.

A 0.6 mm nozzle is a good idea if you have one. Bins are large, simple and unfussy, and printing a drawerful at 0.3 mm layers with a 0.6 nozzle takes roughly half the time with no loss anybody will notice.

The first layer matters more than usual. An elephant’s foot on the bottom of a bin eats into the half millimetre of clearance the system allows, and a bin that binds in its baseplate is almost always a first-layer squash rather than a generator error. If the bins from this page are tight, check that before anything else.

Why the model comes out watertight

A generator like this is usually built by making a solid block, making a smaller block and subtracting one from the other. That needs a mesh boolean, which is thousands of lines of fragile code and is at its worst on exactly the case that matters here: two flat surfaces meeting along a long straight edge.

None of it is necessary. A bin is one continuous surface — down the outside, over the rim, down the inside, across the floor — and it can be swept directly. Every triangle comes out correct by construction, and there is no boolean anywhere to go wrong.

The result is that the STL from this page is watertight every time, with no self-intersections for your slicer to argue about. There is a test in this project that builds a few hundred different combinations of these settings and checks that every one of them is a closed solid.