I 3D-printed custom ESP32 cases, and my projects finally look finished

Ayush Pande is a PC hardware and gaming writer. When he's not working on a new article, you can find him with his head stuck inside a PC or tinkering with a server operating system. Besides computing, his interests include spending hours in long RPGs, yelling at his friends in co-op games, and practicing guitar.

Despite spending my first couple of weeks making aesthetically pleasing models from my 3D printer, I ended up pivoting to functional prints after realizing all the useful items I could create with it. And I’m not just talking about random kitchen accessories and QoL models capable of solving minor problems, either.

For one, my 3D printer is the sole reason my home lab looks somewhat clean instead of devolving into a rat’s nest, one with wires strewn everywhere. Likewise, I’ve used it to create USB device holders, Gridfinity drawer setups, and even replacement feet for my NAS rig. But since I spend a lot of time messing around with ESP32 microcontrollers, I’ve started using my 3D printer to create cases for them, including ones with a lot of customized compartments for my sensor modules.

3D-printed ESP32 cases give my projects a clean look

And they protect my DIY outdoor ESP32 devices, too

Although I love my Wi-Fi-powered ESP32 motion detection sensor and C6 thread border router, most of my ESP32 projects involve a sensor or two hooked up to the microcontroller via a handful of jumper cables. In some rare situations, I’ve also had to toss small breadboards in my experiments to connect more modules to my ESP32. Messy circuitry projects that remain forever confined to my desks aren’t that big of a deal, but the extra clutter is a bit of a hassle for the devices I typically scatter around the house.

My weather station, for example, would look far uglier if I just left it sitting in the living room with the BME280 sensor and a bunch of wires dangling off my ESP32. Likewise, my mmWave ESP32 presence detection setup would look out of place if I didn’t create a proper case. Worse still, I sometimes work on projects where I need to leave my ESP32 + sensor combo outdoors, and without some sort of protective casing, I doubt most of them would last longer than a few weeks, let alone months.

I often customize my ESP32 cases via FreeCAD

Otherwise, my cases wouldn’t even fit my ESP32 clone boards and sensor modules

Technically, I could avoid the extra hassle of 3D printing my own ESP32 cases and opt for pre-built ones, and it would save me a lot of time that I’d otherwise spend sifting through models or designing my own. But I’d be missing out on the customization front, and that’s pretty important for projects involving ESP32 modules. For one, I’ve got my fair share of ESP32 microcontrollers that have weird button placements that wouldn’t fit into conventional cases.

My ESP32-S3, for example, has the BOOT and RST buttons placed on the other side of the board, and this layout would cause issues if I tried shoving it into a prebuilt case from Amazon. Instead, I could scour the web for 3D printed cases and just edit some parameters to make them match the dimensions of my tiny tinkering companion.

Then there’s the sensor part of the problem. If I wanted my DIY weather station to sit in the corner of the living room, the BME280 and its jumper cables would remain outside the tiny case. With FreeCAD (yes, I still haven't switched to other tools), I could slot an extra compartment around the ESP32’s GPIO pins to accommodate my sensor. And for projects involving full-on breadboards and circuits, I can fine-tune all the measurements instead of dealing with the compromises of a pre-built case.

Not to mention, my custom 3D printer cases are more cost-effective than anything I could find online. Now, before you point out that my 3D printer’s price tag negates this whole price comparison, let me add that it was a one-time investment – and between all the custom home accessories and replacement models for products that I would’ve otherwise tossed in the bin, I already made back the amount of money I spent on it last year.

If the average ESP32 case costs about $2–10, I could print one with 15 grams of filament, essentially bringing its cost down to $0.30–50. Even if you include the different iterations I often create for a sensor + ESP32 combo, I’d probably spend less than $1.5 on a case that’s fully customized to my liking, not a pricier case that couldn’t even fit my microcontroller accessories.

I always go with PETG for my custom 3D-printed cases

And I always follow my checklist of necessary design elements when building a case from scratch

As for the filament material for my ESP32 cases, PETG is the one I use most of the time. It’s easier to print than other complex filaments, while being almost as affordable as PLA. It also helps that PETG bends and breaks instead of shattering under load, making it better than PLA for ESP32 cases that I need to mount somewhere. My ESP32-CAM’s case is a great example, and the same holds true about the Espectre motion detection setup I’ve mounted around the back of my home lab.

Likewise, I often try to utilize every last drop of performance out of my ESP32 boards, which causes them to grow a bit hot in certain projects. Unlike PLA, PETG can tolerate higher temps, so I don’t have to worry about the case getting deformed if I leave it running 24/7, and I always leave a tiny ventilation gap near the chip to give it some breathing space.

While we’re on this subject, I also follow a couple of other rules when I build a fresh case instead of tweaking existing models. I leave a tiny bit of clearance (around 0.3mm) around the PCB perimeter to ensure that my ESP32 slides right into the case. For general-purpose cases, I often add some cantilevered arms on top of the RST and BOOT buttons, so I don’t have to take the whole case off just to reflash my microcontrollers. Meanwhile, if I’m working with sensors that require as much precision as DHT22/BME280 modules, I’d isolate them from the rest of the board to prevent the ESP32’s heat from tampering with the readings.

3D printing customized cases gets really addicting once you get the hang of it

Although I still encounter the occasional misalignment or make slight mistakes when tacking extra compartments to pre-existing ESP32 case models, I must admit that 3D printing my own components is more fun than I’d initially expected. Sure, it’s a bit complex at first, especially with CAD tools other than TinkerCAD. But when you get accustomed to building custom microcontroller cases, it’s hard not to overengineer the models or add wacky little details to them.