---
title: "A 3D printed case for a device you own: remote, GPS tracker, power bank, sensor, the lot"
description: "Design a printed case or sleeve for any gadget from six measurements: clearance, wall, button and port cutouts, sleeve or snap lid, and a prompt per type."
canonical: https://speakcad.com/blog/case-for-a-device-you-own-remote-tracker-power-bank
published: 2026-10-19
updated: 2026-10-19
publisher: SpeakCAD
---

# A 3D printed case for a device you own: remote, GPS tracker, power bank, sensor, the lot

> Design a printed case or sleeve for any gadget from six measurements: clearance, wall, button and port cutouts, sleeve or snap lid, and a prompt per type.

A case for a bare circuit board gets a hundred published designs. A case for the thing in your drawer, the GPS tracker that goes on the bike, the old remote whose battery door is lost, the power bank that lives in the car, gets none, because nobody else owns exactly that. It is also the easiest kind of case to design: a box with a hole the shape of the device, and a few cutouts where you need to reach it.

## Six measurements

1. **Length, width and thickness** of the device at its widest point. A remote is wider at the top; a power bank bulges at its buttons; a tracker's lid may be domed. Measure the biggest.
2. **Where the buttons are**, from one corner, with their size.
3. **Where the ports are**, from the same corner, with their size. A USB-C plug needs a hole about 12 × 7 mm, more if the cable has a fat shell; measure the plug you will use, not the socket.
4. **What must stay uncovered**: the sensor window, the LED, the speaker grille, the charging contacts.
5. **How it is used**: handheld, screwed to a wall, strapped to a frame, stuck under a shelf. This decides the mounting.
6. **How often it comes out.** Once a year to change the battery, or every day.

If you have never measured for a print, [how to measure an object for a 3D printed part](/blog/how-to-measure-an-object-for-a-3d-printed-part) takes ten minutes and saves a reprint.

## Pick the case type from how often it opens

| It comes out | Case type | Clearance | How it holds |
|---|---|---|---|
| Daily (remote, phone, power bank) | Open sleeve or tray with a lip | 0.5 mm per side | Friction, a thumb cutout to push it out |
| Monthly (tracker, sensor battery) | Snap lid | 0.2 to 0.3 mm | Cantilever clips, 0.2 mm interference |
| Rarely or never (outdoor sensor, hidden tracker) | Lid screwed on | 0.3 mm | Four screws, M3, into printed bosses |

Walls: 1.6 mm (four perimeters at a 0.4 mm nozzle) for a sleeve, 2 mm for a case that gets dropped or strapped to something that vibrates. Round every outside corner you can; a 2 mm radius on the vertical corners and a 1 mm fillet on the top edges make a printed case feel like a bought one and stop it catching on a pocket.

## Cutouts: a millimetre wider than the thing, placed from one corner

Make each cutout 1 mm wider and taller than the button or the plug, centred on the measurement you took from the corner. A button under a 0.8 mm flexible membrane printed in TPU is possible but fussy; a plain hole you press the button through works and is what most people want. For a port on the bottom of a sleeve, cut the sleeve's floor away under it instead of a precise hole: the cable finds its way and alignment stops mattering.

## Mounting the case to something

- **Wall or ceiling:** two countersunk holes for M4 screws, 2 mm from the back wall, so the screw heads sit flush.
- **A bike frame, a pole, a pipe:** a saddle on the back shaped to the tube's diameter with two slots for a zip tie or a hose clamp; measure the tube.
- **Under a desk or shelf:** a flat back with two screw holes, or a flange with a slot for double-sided tape.
- **A belt or a strap:** a 25 mm slot through two lugs at the back.
- **A keyring:** a 5 mm hole through a 3 mm lug.

## Typing it into SpeakCAD

Name the device, give the six measurements, say how it opens and how it mounts. The AI builds the case, adds the clearance for the fit you described, and states the sizes in its reply; if the device is a product it can look up the published size online first (2 credits more), then still asks for the one measurement that decides the fit when it could not find it. Check the cutout positions in the dimensions panel against your notes, and change what is off: moving a cutout is a small change, and on a plan the first 3 small changes of each part are included. For a board rather than a finished gadget, the [enclosure generator](/enclosure-generator) and the [PCB enclosure guides](/blog/pcb-enclosure-generator-any-board) take over, with standoffs and the hole patterns of the common boards.

Or shape it by hand, free: start from a box the size of the device plus walls, use Shell to hollow it to 1.6 mm open on top, Hole or Cut for each port placed by its distance from the edges, Fillet on the top edges, and Text for a name on the back. [The hand tools](/tools) list what each does.

## Printing

Print a sleeve open side up, so the inside walls are clean and no supports touch the fit surfaces. A snap lid prints flat, clips upward. PLA indoors; PETG in a car, outdoors or on a bike, where PLA softens on a hot day. If the case must keep rain out, [the outdoor sensor enclosure](/blog/outdoor-sensor-enclosure-3d-print) covers gaskets, glands and vents.

Shaping a part by hand (a hole, a cut, an added shape, text, rounded corners, a shell, every size typed in millimetres) is free, and so is downloading what you shaped. With the AI, a new part spends 4 credits on a plan with its first 3 small changes free, a design change 3, a small change 2, a quick edit 1; without a plan a new part spends 3. Start with Maker: 50 credits a month for $7.99, cancel anytime.

## Prompts to try

- An open sleeve for a TV remote 165 x 42 x 18 mm, 0.5 mm clearance, 1.6 mm walls, thumb cutout at the top, two M4 countersunk holes in the back to screw it to the side of a cabinet ([open in SpeakCAD](https://app.speakcad.com/signup?next=%2F%3Fprompt%3DAn%2520open%2520sleeve%2520for%2520a%2520TV%2520remote%2520165%2520x%252042%2520x%252018%2520mm%252C%25200.5%2520mm%2520clearance%252C%25201.6%2520mm%2520walls%252C%2520thumb%2520cutout%2520at%2520the%2520top%252C%2520two%2520M4%2520countersunk%2520holes%2520in%2520the%2520back%2520to%2520screw%2520it%2520to%2520the%2520side%2520of%2520a%2520cabinet))
- A snap-lid case for a GPS tracker 52 x 32 x 12 mm, 0.3 mm clearance, 2 mm walls, charging port cutout 12 x 7 mm on one short side, saddle on the back for a 30 mm bike tube with two zip-tie slots ([open in SpeakCAD](https://app.speakcad.com/signup?next=%2F%3Fprompt%3DA%2520snap-lid%2520case%2520for%2520a%2520GPS%2520tracker%252052%2520x%252032%2520x%252012%2520mm%252C%25200.3%2520mm%2520clearance%252C%25202%2520mm%2520walls%252C%2520charging%2520port%2520cutout%252012%2520x%25207%2520mm%2520on%2520one%2520short%2520side%252C%2520saddle%2520on%2520the%2520back%2520for%2520a%252030%2520mm%2520bike%2520tube%2520with%2520two%2520zip-tie%2520slots))
- A car holder for a power bank 142 x 68 x 15.5 mm, open top, floor cut away under the USB-C port, 2 mm walls, flange with a slot for double-sided tape ([open in SpeakCAD](https://app.speakcad.com/signup?next=%2F%3Fprompt%3DA%2520car%2520holder%2520for%2520a%2520power%2520bank%2520142%2520x%252068%2520x%252015.5%2520mm%252C%2520open%2520top%252C%2520floor%2520cut%2520away%2520under%2520the%2520USB-C%2520port%252C%25202%2520mm%2520walls%252C%2520flange%2520with%2520a%2520slot%2520for%2520double-sided%2520tape))

## FAQ

### How much clearance should a 3D printed case have around a device?

0.5 mm per side for a sleeve the device slides in and out of every day, 0.2 to 0.3 mm for a snap-lid case it stays in, and 1 mm wider and taller than each button or plug for the cutouts. Walls of 1.6 to 2 mm.

### Can I 3D print a case for a device without CAD skills?

Yes. Measure the device at its widest point, note where the buttons and ports are from one corner, and type that into SpeakCAD with how the case opens and mounts; the AI designs it with the clearance and shows every size. Or hollow a box by hand with Shell and place the cutouts by their distance from the edges, free.

## About SpeakCAD

SpeakCAD is the most intuitive CAD for 3D printing, made for people who own a 3D printer and need a part that fits something they have: tap a face and type a size to shape it with simple tools, or describe it to the AI, on your phone or computer, and download a print-ready STL, 3MF or G-code sliced for your printer.

SpeakCAD works inside ChatGPT and Claude as a plugin (an MCP server): ask the assistant for a part with its measurements and SpeakCAD's own CAD AI designs it, shows it in 3D in the chat and hands over a print-ready STL, 3MF or G-code sliced for your printer.

- Live demo, no account: https://speakcad.com/demo
- In ChatGPT, Claude and other MCP clients: https://speakcad.com/chatgpt-plugin, https://speakcad.com/claude-connector, https://speakcad.com/mcp-server
- Pricing: https://speakcad.com/pricing
- FAQ: https://speakcad.com/faq
- Site index for AI assistants: https://speakcad.com/llms.txt