Gridfinity is a 42 mm grid. Drawers are not. Almost everything awkward about fitting one to the other comes from that single fact, and most of the questions below are really the same question in different clothes: what do I do with the space that isn't a whole number of cells?
This page covers the decisions the tools ask you to make, and why they're asked. If you'd rather just start, open the baseplate generator and put your drawer's dimensions in — everything here is also explained in place as you go.
Measuring your drawer
Measure the inside of the drawer, at its tightest point. Drawers are rarely square: runners bulge, joints leave fillets, and a drawer that measures 306 mm at the front can measure 304 mm at the back. Take the smallest number you find.
Then subtract 1–2 mm from each dimension. A baseplate that exactly matches the opening has to be forced in, and a printed plate has nowhere to go once it's seated. Two millimetres of slack is invisible in use and makes the difference between dropping the plate in and hammering it.
Working in inches? The grid is metric and the tools are millimetre-based, so convert once and work in millimetres from there: multiply inches by 25.4. A 12 inch drawer is 304.8 mm, which gives you seven cells with 10.8 mm left over.
What happens to the leftover space
A 306 mm drawer holds seven 42 mm cells — 294 mm — leaving 12 mm spare. You have three sensible options:
- Fill it with solid margin. The plate is printed at the full drawer size with a solid border. The plate can't shift, and the border gives the joints something to bite into. This is the default.
- Leave it as a gap. The plate is grid-only and sits loose by the leftover amount. Fine when the drawer walls contain it and you'd rather not spend the filament.
- Put it where you want it. Margins can be set per side, so you can push the grid to the back of the drawer and keep the spare space at the front where you reach in.
If the leftover is close to a whole cell — more than about 30 mm — re-measure before you commit to it, because losing a column to a millimetre of error is easy to do. But it's usually real. The remainder can be anything short of a full cell, and ordinary sizes land high: a 200 mm drawer leaves 32 mm, a 500 mm drawer leaves 38 mm, and neither is a mistake. Push a leftover that size to one side rather than splitting it, because one wide strip is usable and two narrow ones aren't.
When the baseplate is bigger than your printer
This is the most common reason people give up on Gridfinity for drawers. A 306 × 380 mm drawer needs a plate far larger than any consumer bed, so it has to be printed in pieces and joined.
The largest single piece a 256 × 256 mm bed will take is six cells along an axis — 252 mm, since baseplate pieces tile at the full 42 mm pitch. On a 220 × 220 mm bed it's five cells, 210 mm. (A bin is 0.5 mm smaller than the cells it sits in, however many it spans: n × 42 − 0.5, so 41.5 mm for one cell and 251.5 mm for six. Easy to conflate the two.)
Rotating the piece diagonally doesn't help, which surprises people. A rectangle's bounding box is smallest at 0° or 90°, so a piece longer than the bed stays longer than the bed at every angle. Splitting is the only answer.
How you split matters more than it looks:
- Balanced divides the plate evenly. Simple and predictable.
- Staggered offsets the joints between rows like brickwork, so no seam runs the full width of the drawer. Noticeably more rigid.
- Fewest plates searches split patterns and picks the one needing the fewest bed loads — it will often pair two narrow pieces on one plate that a naive split would print separately. Usually the best starting point.
The baseplate generator shows the resulting pieces on a cut map, and you can click any grid line to move a cut by hand.
Choosing a joint
Split pieces need to be held together, and the right joint depends mostly on how you'll assemble it rather than on strength. Every shape below is drawn from the same numbers the plates are cut with, viewed from above with the seam running across the middle.
- Dovetail tabs — printed onto the pieces, no loose parts, no extra filament. Lay the tabbed piece down first and lower its neighbour onto it. The tab is wider where it's buried than at its mouth, so it only goes in vertically.
- Puzzle tabs — a jigsaw lock, the strongest in-plane joint, but it adds a solid floor to house the lobes and that costs filament.
- Keys and clips — separate printed parts that bridge the seam. They can sit in a solid floor (strongest) or inside the grid walls (no extra filament at all).
- Inserted from above — worth knowing about if you can't lower an assembled plate into the drawer. Lay the pieces in place and drop a key into each junction from the top.
Whichever you choose, print the joint fit sample first. It's four tile pairs at graduated clearances in one small print, and it tells you in five minutes which fit your printer actually produces — far cheaper than discovering it after a drawer's worth.
Bin heights, and what actually fits
Bin heights are quantised to 7 mm units, and the single most common misunderstanding is what that measures. The 7 mm is the bin's total height, including its own base — not height added on top of it.
A Gridfinity bin's foot is 4.75 mm tall. So a 1-unit bin is 7 mm overall, of which 4.75 is foot and about 1.2 is floor, leaving roughly 1 mm of usable cavity. That's why 1-unit bins are rarely worth printing, and why every extra layer in a stack costs you another 5.95 mm of base before it holds anything.
| Units | Total height | Usable depth inside |
|---|---|---|
| 1 | 7 mm | 1.05 mm |
| 2 | 14 mm | 8.05 mm |
| 3 | 21 mm | 15.05 mm |
| 4 | 28 mm | 22.05 mm |
| 5 | 35 mm | 29.05 mm |
| 6 | 42 mm | 36.05 mm |
Three separate things stack up above your drawer floor, and it's easy to conflate them: the baseplate (4.25 mm, and not part of the 7 mm units), the bins (7 mm × however many units), and the stacking lip on the topmost bin (about 4 mm, and also not part of the units).
So the arithmetic for a drawer is:
4.25 + 7 × (total units) + 4 ≤ your usable height
An 84 mm drawer gives 79.75 mm above the plate, which works out at ten units in total — 5 + 5 across two layers, or 4 + 3 + 3 across three. The bin designer does this sum for you and warns before you overshoot.
Stacking bins in layers
Bins stack because each one's lip is shaped like a baseplate socket — a bin sits on a bin exactly as it sits on a plate. Two things decide whether a stack actually works:
- Support at two opposite edges. A bin spanning a gap between two others is fine — it's a plank on two beams. A bin resting entirely on one side of its centre tips.
- Don't sit inside a bigger bin's footprint. The lip runs around the perimeter; the middle is open cavity. A small bin placed inside a large one's outline has nothing underneath and drops in. Span the bin below across its full width or its full depth and you're on its rails.
Common questions
Do I need magnets?
In a drawer, usually not. The plate is contained by the drawer walls and the bins are held by the sockets. Magnets matter most when a plate is carried around or mounted vertically. They also force a solid floor, which is a real filament cost.
My drawer isn't a rectangle. Can I still use it?
Partly. You can size the grid to the largest rectangle that fits and leave the awkward region empty, or set per-side margins to push the grid away from an obstruction. Arbitrary outlines aren't supported yet.
Will these bins fit baseplates I already have?
Yes, provided yours follow the published Gridfinity spec — 42 mm pitch, 41.5 mm bins. Some generators produce thicker, padded plates that aren't spec; parts aren't interchangeable with those.
How much filament is a full drawer?
More than people expect. A 7 × 9 drawer filled with 4-unit bins is comfortably over half a kilo and days of printing. The bin designer estimates material as you go, at your slicer's infill setting, so you can see it before you commit.
What's the difference between a solid and a skeleton baseplate?
A skeleton plate leaves out the bulk beneath the sockets, keeping the rim and the wall band. It's lighter and faster to print. Cells carrying a joint stay solid, and it's unavailable with magnets or screws, which need that material.
Do I have to print the whole drawer at once?
No, and it's a bad idea to try. Print one bin first and check it seats in your plate before committing to a drawer's worth. The layout you plan is saved in the page URL, so you can come back to it later.
Going further
- Baseplate too big for your printer? — how many cells each bed takes, why rotating diagonally never helps, and how to split and rejoin well.
- Drawer size to grid — reference tables in millimetres and inches, and what to do with the leftover space.
Start with the baseplate generator → · Plan a drawer of bins →