Hinged box, customizable: print-in-place hinge and snap latch, any size

A small storage box with the hinge printed in place along the back and a snap latch at the front. The default is 100 x 60 x 40 mm outside with 2 mm walls, split into a 20 mm base and a 20 mm lid. Set the length (60 to 200 mm), the width (40 to 150 mm), the height (30 to 100 mm), the wall (1.6 to 4 mm) and the number of hinge knuckles. The height always splits half and half, so both halves print flat.

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

Parameters

Outside lengthmm

Outside widthmm

Outside height (closed)mm

Wall thicknessmm

Hinge knuckles (odd)

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

It prints in one piece with the lid lying open beside the base, both as open trays, with no supports. Two flexible arms on the lid hook into slots in the base wall, and a thumb tab between them lifts the lid. The hinge has 0.35 mm gaps and the latch arms sit 0.15 mm off the base, as measured below, so print one box before a batch. The arms and tab stick out at the front: the footprint is about 69 mm deep.

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
Outside length	60 to 200 mm	100 mm	Outside length along the hinge. The hinge runs the full length minus 11 mm at each end, where the open stops sit.
Outside width	40 to 150 mm	60 mm	Outside depth from the front wall to the back wall, not counting the hinge and the latch.
Outside height (closed)	30 to 100 mm	40 mm	Closed outside height. It splits half and half between base and lid.
Wall thickness	1.6 to 4 mm	2 mm	Thickness of the walls, the floor and the lid top.
Hinge knuckles (odd)	3 to 9	5	Number of hinge knuckles, always odd. More knuckles make shorter segments along the same hinge.

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
Outside length	100 mm	100 mm
Outside width of the box body (without hinge and latch)	60 mm	60 mm
Closed outside height	40 mm	40 mm
Side wall thickness	2 mm	2 mm
Print-in-place gap around the hinge knuckles	0.35 mm	0.35 mm
Smallest gap between lid and base: the latch arms off the front wall	0.15 mm	0.15 mm

base: valid solid, one body, 100 x 65 x 23 mm, fits a 256 x 256 x 256 mm printer; overhangs: 1.0% of surface would need support.
lid: valid solid, one body, 100 x 69 x 37.5 mm, fits a 256 x 256 x 256 mm printer; overhangs: 0.8% 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: In one piece with the lid open flat beside the base (the download is laid out this way): both halves are open trays standing on their floors.
Supports: None
Material: PLA (the latch arm strain was checked against a PLA limit)
Layer height: 0.2 mm
Hardware: None
Time and filament: About 2 h 45 min and 60 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.

Print one box first. The hinge knuckles and the rim have a 0.35 mm gap; swing the lid a few times after printing to free them.
The latch arms print standing up, with the layers across the bend, and the hooks are only 0.6 mm deep. The arm strain was checked on the model (0.42% against a 1% limit for PLA), but the click itself was not simulated.
Ribs on the two back corners stop the lid when it lies open at 180 degrees, and the rim stops it when closed.

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 small hinged box with a print-in-place hinge and a snap latch, about 100 x 60 x 40 mm outside, 2 mm walls. Size adjustable.

1
Size and print layout first
The agent wrote checks for the 100 x 60 x 40 mm outside size and two printed parts, a base and a lid joined by a hinge with no separate pin. It split the height at 20 mm so the box could print with the lid open and both halves flat on the bed.
2
First build: three problems
The first model had the latch arms inside the box. The motion check found the base and lid touching at rest, so they would fuse, the arms hitting the base wall from 3 to 10 degrees as the lid opened, and nothing stopping the lid at 180 degrees.
3
Arms outside, a rim gap and stop ribs
The agent moved the two latch arms outside the front wall, opened a gap between the rims and added a rib on each back corner of the base and lid that meet when the lid lies flat. The swing then came out clean with a stop at each end. It also fixed the thumb tab and looked at the latch hooks in a cut view.
4
A short box overstrained the latch
The slider sweep found the arms too stiff at the 30 mm minimum height: 1.12% strain against a 1% limit, because the arms get shorter. The agent thinned them from 1.5 to 1.2 mm, which brought the default to 0.42%, and the sweep then found no collision or problem at any of the 10 extremes.
5
What it left to the maker
The box was not printed. Its reply says the latch click is not simulated, only the arm strain, and that the hook depth is not a slider: ask the designer to change it if the latch is too loose or too stiff.

One run of the agent: 5 min 0 s, about $0.56 of model time at list price (claude-sonnet-5-5). The model code behind this page is the code it wrote, unchanged.

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)