Box with sliding lid, customizable: any size, lid play and thumb dish

A two-part storage box: an open box with grooves along its long walls and a flat lid that slides in from the open end. The lid stops against the closed end wall, and a 2 mm lip above each groove holds it down. The default is 120 x 80 x 40 mm. Set the length (60 to 250 mm), the width (40 to 200 mm) and the height (20 to 120 mm), the walls, floor and lid thickness, the groove depth, the lid play and the thumb dish.

Customize Change it with AIFree STL, 3MF and STEP, no accountMeasured on the model

Parameters

Outer lengthmm

Outer widthmm

Outer heightmm

Wall thicknessmm

Floor thicknessmm

Lid thicknessmm

Groove depth into wallmm

Lip above the lidmm

Lid play (per side)mm

Finger dish radiusmm

Sliders and downloads are free. Changes by the AI designer use credits like any design; new accounts start with free ones.

The box prints open side up and the lid prints flat, neither with supports. In the viewer the lid sits closed and Play slides it out along the grooves. The lid has 0.3 mm of play per side, above and below, as measured on the model below. That play is an assumption: print a short test if your printer runs tight, and raise Lid play if it binds. Nothing holds the lid shut at the open end, it slides out freely that way. The lid top sits about 2.3 mm below the rim.

Parameters

Every slider in the viewer above, with the range the model accepts. The model rebuilds valid at both ends of each range.

Parameter	Range	Default	What it changes
Outer length	60 to 250 mm	120 mm	Outside length. The lid slides along this direction, in from the open end.
Outer width	40 to 200 mm	80 mm	Outside width, across the two grooved walls.
Outer height	20 to 120 mm	40 mm	Outside height. The grooves stay at the top, so a taller box adds depth under the lid.
Wall thickness	2.4 to 5 mm	3 mm	Wall thickness. A groove never cuts more than half of it.
Floor thickness	1.6 to 5 mm	2.4 mm	Thickness of the box floor.
Lid thickness	3 to 6 mm	4 mm	Thickness of the sliding lid. The grooves grow with it to keep the same play.
Groove depth into wall	1 to 2.5 mm	1.5 mm	How far each groove cuts into the side wall, which is how far the lid edge reaches under the lip. Capped at half the wall.
Lip above the lid	1.6 to 4 mm	2 mm	Height of the lip above the lid that keeps it in the grooves.
Lid play (per side)	0.2 to 0.5 mm	0.3 mm	Play around the lid in the grooves, per side, and at the stop. Raise it if the lid binds, lower it if it rattles.
Finger dish radius	8 to 25 mm	12 mm	Radius of the round thumb dish cut into the lid near the open end. The dish stays up to 2.2 mm deep, so a larger radius makes it wider.

Proof: measured on the model

What the design must satisfy and what our CAD engine measured on the model at the default values. Only measured values are shown here; nothing on this page has been printed by us yet.

Requirement	Wanted	Measured
Box outside length	120 mm	120 mm
Width between the groove bottoms	77 mm (74 mm inside + 2 x 1.5 mm grooves)	77 mm
Lid width	76.4 mm (0.3 mm play per side)	76.4 mm
Groove height	4.6 mm (4 mm lid + 0.3 mm above and below)	4.6 mm
Lid thickness	4 mm	4 mm
Lid length	116.7 mm: it stops 0.3 mm short of the 3 mm closed end wall	116.7 mm

box: valid solid, one body, 120 x 80 x 40 mm, fits a 256 x 256 x 256 mm printer; overhangs: 0.7% of surface would need support.
lid: valid solid, one body, 116.7 x 76.4 x 4 mm, fits a 256 x 256 x 256 mm printer; overhangs: 0.0% of surface would need support.
Motion: 1 moving joint swept through its range with every pose checked for collisions, no problem reported at the defaults. See the Joints tab in the viewer.

Print notes

Orientation: The box stands open side up; the lid lies flat with the thumb dish facing up (Print plate in the viewer, which shows the lid closed in its grooves by default).
Supports: None (the groove roofs are short 1.5 mm overhangs under the lip)
Material: PLA or PETG
Layer height: 0.2 mm
Hardware: None
Time and filament: About 4 h and 90 g at the default size: a rough estimate from the model's volume and surface (PLA, 15% infill, about 1 mm of walls, 0.2 mm layers), not a slicer.

Slide the lid in from the open end, the one with the cut-down wall, until it stops against the closed end.
The 0.3 mm play per side is the model's assumption. To test it cheaply, print the lid and a short box first (lower the outer length), and raise Lid play if it binds.
Push the lid open with your thumb in the dish; it has lid material on the open side to push against.

How it was designed

Designed with buildcad's AI agent, checked by the buildcad team. This is the request it started from and an edited account of what it did (more on how text to CAD works).

The request
A box with a sliding lid that runs in grooves, about 120 x 80 x 40 mm, with a finger notch on the lid and a stop so the lid doesn't slide out the closed end.

1
It planned the size, the fit and the stop
The agent wrote checks for the 120 x 80 x 40 mm outside size, a 4 mm lid with 0.3 mm of play per side in the grooves, and one solid each for the box and the lid. It made the stop with blind grooves: they end at the closed end wall, so the lid cannot leave that way.
2
First build: tight above and below
The first model met every check, and the lid, put back in the grooves for a test, parked 0.3 mm short of the end wall. But the gap above and below the lid was only 0.15 mm, which the agent judged tight for printing.
3
Taller grooves
The agent made each groove 4.6 mm tall, the lid plus 0.3 mm above and below. The test fit then measured 0.3 mm everywhere with no overlap, and the slider sweep rebuilt all 20 extremes as one valid body per part.
4
The thumb dish, and what it left open
It used a round thumb dish near the open end instead of a notch through the lid edge, so the thumb has an edge to push against. On the model the dish is about 14 mm across and 2.2 mm deep. It did not print the box, and its reply suggests a short test print to confirm the sliding fit.
5
Our change
We made the model an assembly: the lid sits closed in its grooves and slides out along them in the viewer. The sweep measures 0.3 mm of play along the whole travel, finds the closed end wall as the stop at 0 mm, and the lid out of the grooves at the far end. The print plate lays both parts flat for the downloads; their shapes are unchanged.

One run of the agent: 1 min 35 s, about $0.21 of model time at list price (claude-sonnet-5-5). We changed the code afterwards, as described in the last step.

Change it with AI

Set the sliders, then press Change it with AI: a copy goes to your designs at those sizes and the designer opens with a suggested change you can edit. Its changes use credits like any design; new accounts start with free ones.

Change it with AI Describe your own part Use it from your own AI (MCP)