Parametric Rugged Case, Gridfinity-Ready, Multi Lid Style

Your size. Your grid. Your style.

A rugged case you print to the exact size you need and optionally Gridfinity-ready. Pick one of the three ready-made sizes if you just want to print and go, or type in your own internal dimensions and the box builds itself around them. Latch and screws are all printed. There’s no hardware to buy.

What you get 📦

• Fully parametric. You give it the inside dimensions, the usable cavity, and the outside is worked out for you (wall, latch and hinges all live outside the usable volume). Most boxes make you fight the outside to get the inside right. Here you ask for the inside and forget the rest.
• Three pre-set sizes. S, M and L, dialled in and tested. If you don’t want to touch a parameter, just grab the size you need.
• No hardware. Latch and screws are printed, no metal anywhere, and the hinge is part of the body. They’re also identical on every size, so one printed set covers all your boxes, and a broken part is just a reprint.
• Gridfinity-ready, not gridfinity-only. An optional gridfinity baseplate is built into the floor (42 mm pitch), so standard bins drop straight in. Not into gridfinity? Grab the custom model and it’s a plain case.
• Three interchangeable lids. Two with sci-fi engraving (radial and circuit) and one plain, which you can leave bare or run in multicolour with an AMS.

Using it with gridfinity 🧩

The baseplate is molded into the floor at the standard 42 mm pitch, so any standard gridfinity bin sits in it. I’m not shipping a bin generator, there are already good ones out there, so make the bins you need with whatever generator you already trust.

• Gidfinity Generator
• Gridfinity Rebuilt

Two things worth knowing.

Height. In gridfinity mode you set the inside height in U. The catch is that “U” gets measured differently by different generators: the bin’s stacking lip (roughly 4.4 mm) is counted inside the N×7 by some and added on top by others. So measure the bin you actually have in your hand and use that number. One U is 7 mm.

When in doubt, trust your calipers.

Tall bins. If a bin is as tall as the whole case, shave its front edge at an angle. The lid swings on a hinge, and a full-height bin sitting right at the front lip will catch the lid as it closes. A small diagonal cut on the front face of the bin clears it. Check picture below.

Printing and assembly 🛠️

• Material: It depends on your use, generally speaking I would use PETG, but PLA would work too.
• Orientation: the lid prints upside down, top face on the plate, so the engraving comes out crisp. Screws: yes, they print vertically, and yes, I know that usually means fragile. I've printed and used dozens of them and not one has broken. The trick is simple: don't overtighten. They don't need it, hand-snug is enough.
• Supports: the only support you need is a small one under the lid catch pin. Everything else prints support-free.
• Warping: on big sizes you could get warping (edges lift up while printing). I solved it using a plate with glue, but a brim or an elephant-foot setting should work too. Keep this in mind if you print big boxes.
• Assembly: simple. Put the lid on and close it, insert the two screws in the back hinges and tighten them (by hand is enough, don’t force them). Take the latch and push it into the front hinges. Ready.
• Tolerances: the XY clearance is parametric, set to 0.4 mm total by default (0.2 per side). If your printer runs tight or loose you can adjust it.

If you are printing from parametric check setup below.

Pre-set sizes 📐

Remember the external size is an output. You set the inside, and the wall, the latch, the hinge and the hook add up to the outside on their own. Depth is free in mm in both modes, so the table is a starting point, not a limit.

Customizing your own box ⚙️

There are six ready-made versions to pick from: two ways to size the box (gridfinity or custom) times the three lids. Pick the row that matches how you think.

The gridfinity versions have the baseplate active, good if you’re building around bins you already have. The custom versions have no baseplate (but you could add it as standalone part like the bins), good if you just want a case of a specific size. One U is 7 mm, so in the gridfinity versions the height steps in 7 mm units, while in the custom versions you set it freely in mm. Every parameter has a safe min/max already set. You'll see the limits in the customize panel, stay within them and it'll generate fine.

Once you’ve got your size, you download a single 3mf with everything in it. To print:

1. Open the 3mf in Bambu Studio.
2. Right-click the model.
3. Split → To Objects.
4. Arrange the parts on the plate and set up the slicer (see Printing and assembly above).

Printing from the parametric source (no preset profile) 🧩

If you download the print profile, everything is already set and you can ignore this. This is only for people slicing the parametric model from scratch.

Global settings:

• Enable "slow down for overhangs".
• Layer height 0.20mm. You can go lower for a finer finish, but 0.20mm is enough for everything except the threaded hardware (see below).

Per-object settings:

• Lid: place it top face down on the plate (engraving against the plate). Add a small support under the front catch pin only (should be added by default when support is enabled).
• Bolt and cap nut: print these at 0.12mm. The finer layers are what let the threads come out clean and turn properly.

The closure, and the honest bit about water 💧

The latch is a snap. I went through a couple dozen prototypes first. An over-center toggle looked great on paper but it’s too fragile to print tolerances, so the snap won: it held better and took the cycling without complaining.

About water, straight talk: this is splash and dust resistant, not waterproof. FDM parts are porous along the layer lines, and TPU isn’t soft enough to spread and seal, so no printed gasket holds up well, I've tested a lot. I’d rather say that than have you find out in a river. There’s a tongue-and-groove channel around the rim: leave it empty (the labyrinth alone stops splashes, dust and pocket lint) or press in a soft TPU cord, a silicone cord or a rubber elastic to push it further. For real watertightness this article on closable prints is the best reference, short version being that an O-ring with silicone grease beats any printed seal.

If you try something in that channel and it works, tell me. I’d like to collect what people find.

Notes 📝

If you liked my older Travel Box, this is a different take on the same idea, rebuilt from scratch. Not a successor, just the same itch scratched a different way.

Print it, post a make, drop a comment. I read them, the feedback on the last one shaped half the decisions here.

Credits: Gridfinity by Zack Freedman, licensed CC-BY. The baseplate follows the standard gridfinity spec.