Introduction To Electronics Project Boxes
You’ve just made something great: It blinks, it whirrs, it speaks in tones, it’s voiced-controlled and it’s “cloud connected” (of course). And now this assembled heap of your own design is waiting on your desk for the final touch. If you want to keep your electronic creation alive for years to come, and draw fewer eyes as you ferry it through airport security, you’ll want to make a robust electronics project box to house and protect it.
The benefits of a small electronics case are clear: Your project will last longer, work more reliably and demonstrate a detailed attitude about showing off your work. It’s time to think outside the box when it comes to thinking about the insides of boxes.
But where to start? Where to finish? This post will guide you through the many different kinds of materials, joinery and aesthetic options for your electronics project enclosure.
Electronics Enclosure Design
Let’s define the challenges encountered when creating your own electronic enclosure design and how you can solve them.
Space And Routing
An important step before beginning any enclosure design is simply figuring out how big your case needs to be. A simple way to do this is to just lay out all of your components on a flat surface and begin compactly arranging them.
How much clearance can you get away with above and below your PCB? Even if you’ve just got a single beefy capacitor sticking out of your board, you’ll need to adjust the effective volume of your enclosure now while the design is still flexible. If you have panel mounted switches or lights, consider not only how to arrange them on the walls of your case but also how to keep cable lengths to a minimum by adjusting the position of remaining components.
While the electrons in your circuit are eager to find that lovely path of least resistance, you probably want them to take a certain route and keep all components from shorting and loosely jumbling about in your enclosure. Every component will need to somehow be secured in its spot, and you’ll need to consider the motion it will endure when fully housed.
For PCBs and other flat components, screwing them into the enclosure is often the most practical means of fastening to the case. (Many pre-made cases will have grooves molded along the walls to allow a board to slide in and out easily.) You can also add standoffs or threaded inserts for a secure point of contact.
Consider if your case will need to stand up to constant vibrations (as a new widget in a car, for instance). You may need to add a locking nuts, o-rings or other special washers, so as to preload your screws and keep them from wiggling free. If you don’t want to bother with screws, then most any component or board can be mounted with a generous helping of hot melt glue or a dab of epoxy.
Most anything can be assembled once. But how often will you need to replace a component? Take into account how likely you will need to access parts of your enclosure and how you might reach them. Nothing says fun like trying to reattach a loose ribbon cable with tweezers because you made the design too small for your own hands.
Consider internally stacking your PCBs and components so they have the fewest points of contact between the parts and the enclosure, as this allows them to be taken out as a whole assembly. Try to mount all electronics to one surface or an internal plate. If you need to have a lot of panel mount electronics, take the extra time to crimp or solder on quick connect terminals so you can cleanly detach the main PCB alone.
Enclosure Design Software
For just about any laser cut case, you’ll want to create your design using a vector graphic editor. I personally survived designing many a project using just Adobe Illustrator and the pen tool. Almost any free vector creation tool will do (I’d recommend learning Inkscape).
The biggest challenge will be learning how to translate a sheet of two dimensional designs into 3D structures. But once you’ve made a box or two, you’ll find the flow of this design process to be pretty easy. If you want to skip any fancy design software, you could also make an interlocking box pattern with just a few keystrokes for a simple laser cut enclosure.
For designs that require more intricate details or if you would like to have something CNC milled, you’ll need to use 3D CAD software to create a solid model of your enclosure (as well as the parts inside). For the programmatically minded, OpenSCAD is a great free solution, if a bit tedious. If you’re like me and need the sweet embrace of a GUI, then I recommend Autodesk’s Fusion 360, which is a very powerful CAD package that is free for most regular users.
Prototype Prototype Prototype
If your design includes an I/O panel, print it out on a sheet of paper at 1:1 scale and break out the calipers. Not only will you be able to confirm dimensions, but also having a physical sense of the design is important while you can make changes virtually and at little cost.
If making a handheld project, cut a rough analog out of wood or stack sheets of cardboard (my personal favorite) to match the size of your piece. Is it comfortable to hold? Can you reach all of the buttons easily? A little UX goes a long way.
Custom Electronics Enclosures
The world is full of plenty of like-minded creatives who’ve made their own custom electronics enclosures, so let’s take a gander at what they’ve shared for some inspiration:
Instead of shelling out for a humdrum premade case, Rich Decibels (definitely a real name), made a sleek black case for his audio filter and documented it in his electronic box tutorial. He took the extra step of making detailed models of his components, which is a must for making especially compact designs such as his.
Even if you don’t make electronics yourself, perhaps you’d be interested in this DIY project box, which goes to show that you too can customize and bring new life to old electronics with a little design work (and a high powered CO2 laser, of course).
The designs linked above represent pretty common techniques for custom boxes. For even more out-of-the-box ideas, take a peek at Make Magazine’s list of interesting electronic enclosures.
If classic arcade games and CNC milling strike your fancy, David Johnson, over on his DIY Engineering channel, has made an impressively detailed and thoroughly enjoyable video about his handheld gaming system. His work on this project is some of the best DIY enclosure design I’ve seen documented by an individual.
Lastly, if you want to see something masterful, go check out the work of Ben Heck. I can’t practically sum up his projects, as the quantity and quality are really just staggering. If you want to fall way, way down the rabbit-hole of crazy, custom electronics enclosures, his projects can’t be beat.
Choosing The Right Material For Your Electronics Project Box
So you’ve got a great design, one that fits your needs and, more importantly, all those dangly wire bits inside. But at this stage, it’s probably just a drawing on a screen. You’ll need to take your digital design (or napkin sketch, I won’t judge) and make it out of something solid and sensible for its future environment.
Will your device live outside in a temperate jungle? Does it need to handle being touched by thousands of interactive guests in the desert or survive a damp night on stage with just your foot smashing it about? There are many factors to consider when making a material selection for your enclosure, but I’ll guide you through the most common material choices and their ups and downs when it comes to cost, quality, and ease of modification and assembly.
Metal Electronics Enclosures
Nothing says “this is a finished product worthy of respect” more than a custom metal case. Having a metal electronics enclosure is often the most expensive housing solution, but it yields the most benefits when it comes to reliability.
One of the most practical advantages that metal enclosures afford, due to their conductive nature, is quality RF shielding. This is especially important for keeping that stray EM radiation at bay (or keeping your own RF pixies in place). Also, a single threaded hole makes for a solid ground connection to the rest of your circuit, which is especially important if you have electronics connected to mains voltages.
We’ll cover the broad strokes of certain metals, but there are more metallurgical differences between alloys that are beyond the scope of this article. (I do recommend diving down that rabbit-hole, however.) Here are a few solid choices:
Strong, heavy and readily available, steel has an amazing cost/benefit ratio that’s hard to beat. If you like playing with fire and high current electronics, welding a good ol’ steel box will yield a nearly unbreakable enclosure, even if it does weigh 10 pounds. And unless you find yourself in the Atacama, you’ll definitely need to protect your steel from oxidization with a proper finish. I’d recommend a powder coat, which will add a solid, glossy finish in nearly any color of your choice at the expense of a little dimensional thickening.
If you’re willing to spring a little extra cash for your enclosure, stainless steel could also fit the bill, especially if you prefer something non-magnetic and capable of withstanding harsh, moist environments.
Softer, cheaper and more easily machinable, aluminium makes for a terrific electronics case. Aluminum can be anodized, which not only provides a protective finish but also allows for colorful dyeing to add a customized, professional look. Anodization can be selectively laser-etched away to provide a dimensionless label or artistic flare for your enclosure. To see just how creatively aluminum can be cut, bent and finished into something beautiful, take a peek at the services offered by Protocase.
A generally soft, yet heavy, alloy, brass enclosures can be soldered, brazed or bent together with relative ease. Whether you have a steampunk heart or not, it’s hard to deny the attractiveness of this classy metal. Although it will cost you (even in small quantities), you can’t go wrong with the shimmering, golden look of brass as your enclosure material.
Wood Project Boxes
For a simpler (and far cheaper) alternative to metal, a wood project box might be the way to go. With a few simple tools such as a drill press and a saw, you can make a wood electronics box that will last for years.
Not only is wood a decent insulator (as far as most low-voltage projects are concerned), but it arguably has the most finishing options of any material. From painting, to staining, to oiling, to clear coat sealing or waxing, you’ll be able to create just the right look for your wood enclosure.
The simplicity of working with wood makes it an attractive material choice. Just take a look at this 2×4 enclosure! You can do some surprising things with a sheet of laser cut plywood, too. Look no further than this Arduino-based radio receiver.
Compared to metal and wood, plastic forms a nice middle ground in terms of cost versus durability. Let’s take a look at a few popular kinds:
Acrylic seems to be the go-to among DIYers looking to make plastic enclosures for electronics projects. Although it is naturally quite brittle, acrylic is an easy choice if you seek colorful cases that can showcase your internals (the PiBow comes to mind). There’s just something special about a neon translucent acrylic box stuffed full of wires and LEDs that’s just so damned cool.
Acrylic can easily be laser etched, generally heat bent to get compound curves and bonded to itself with solvent welding. Since acrylic can build up a static charge, you may want to find or treat your own case to prevent wary discharges through your sensitive electronics.
Acrylonitrile Butadiene Styrene (ABS) is a tough thermoplastic that also makes for a great enclosure. The stuff of LEGO, ABS isn’t prone to shattering like acrylic, and it can be welded together with common acetone for permanent, air-tight seals that make for a durable plastic enclosure. You’ll often encounter premade box enclosures made out of molded ABS in nearly any shape you could want.
If you want to make a case that can take way more of a beating than a mere acrylic box and are perfectly fine with limited color choices, then acetal (often found under the brand Delrin) can do the job. I would talk more about this magical polymer, but Joshua Vasquez already wrote a fantastic multi-part series on how to build anything using Delrin and a laser cutter over on Hackaday.
There are no monolithic rules when it comes to materials for your design. You’re far from limited to the few kinds of enclosures discussed above, so check out Ponoko’s myriad selection of laser cutting materials to see just how many options are available for your design.
Making A Custom Electronics Project Box
Let’s make something ourselves! (Well, you’ll make something. I’ll just stay here, disembodied, barking words of encouragement.) If you want to make a case from scratch, here are a few basic tools for nearly any enclosure build:
Drill – Pick up a good set of bits! You’ll find nearly any electronics project box needs a lot of holes for all those darned LEDs and switches, not to mention the many spots for mounting screws.
Saw – You’ll want something to cut down raw stock for your case. I’d recommend something that moves on its own, but patience and a good handsaw have done just fine for centuries.
Rotary Tool – Use it to make quick work of rough holes and carve out square corners. Be sure to grab extra sanding drums and cut-off wheels.
Files – Take those final light passes to any hole or square edge to get a precise fit that only good old fashioned handwork can provide.
Calipers – Keep measuring your parts and mark your dimensions before you make a permanent cutting decision.
By combining the power of these tools, you’ll be able to take just about any heap of scrap material and make a dashing custom electronics box.
Cases For Single Board Computers And Microcontrollers
If you’ve plunged into the exciting DIY world of embedded computing, you’ll want to have a single board computer case that keeps your project safe and sound. Depending on the board, there are a few different things to keep in mind:
The Uno layout, which also works for the bigger Mega, Due and similar variants, allows for the boards to be screwed in with M3 or 4-40 screws at several points of contact. You’ll want to be sure to leave holes in your Arduino case for the USB port, top mounted pin headers and ICSP port (especially if you may have fried the USB-serial converter chip). A regular Altoids tin fits the classic Uno dimensions quite well if you want a no-frills enclosure, but take care to insulate the bottom of the board from the metal base!
Raspberry Pi Case
The world’s favorite single board computer, the Raspberry Pi (or my preferred abbreviation: RasPi) deserves a respectable case of its own. There are a few things to consider when making an official case for Raspberry Pi:
Raspberry Pi Model A & B
The OG boards have two solid mounting holes, a smaller pin header, and bulky audio and video connections towards the rear of the board that make them incompatible with any cases or enclosures designs you’ll likely find today.
Raspberry Pi B+
Starting with the B+ model, the foundation simplified future case design by adding two more mounting holes and arranging them in a rectangular pattern, as well as combining and moving the audio/video connector to match with the power and HDMI port side. So a B+ case is Raspberry Pi 2 case is a Raspberry Pi 3 case and so on. The model “A” variants are truncated toward the USB side, but they maintain the same mounting points and port locations as the model “B.” You can find some snazzy example RasPi case designs in these Nwazet enclosures.
Raspberry Pi Zero
The original “$5” computer shares the same 40 pin (yet unpopulated) connector as its mainstream model, and it has four mounting holes for secure fastening. This board has quickly seen a few revisions to the 1.3 “W,” which includes a miniature CSI port as well as wireless connectivity built-in, so be sure to add a slit for the wee camera cable, too.
There’s more than one duino on the block and the Netduino has a nearly identical mounting layout as a standard Arduino Uno. Bear in mind that in lieu of the ICSP headers, you’ll find connection points for JTAG, which will require a slight modification to any enclosure’s top plate.
Beaglebone Black Case
A Beaglebone Black case has similar requirements to the Raspberry Pi. You’ll want to keep a easy access port for the micro SD card, a port to the power and USB socket, and holes for the two major pin headers for unfettered GPIO access in your BBB case.
Last, but not least, is the Udoo Case. At 11cm x 8.5 cm, this ARM Linux board needs a bit more space than the rest, but most of the necessary ports are aligned to one side, and it also has a bevy of mounting holes for securely fastening it to any enclosure.
So that’s the basics when it comes to making a case for your electronics. I hope you’ve found some solid inspiration and gained more practical insight into creative and robust enclosure design (I know I have). Let me know if you have any questions by leaving a comment below. Now then, get out there and make something!