I needed something to test out a low-power laser cutter, and thought that some small cardboard boxes would fit the bill nicely, so off I went to scour the Interwebs for a quick-and-dirty finger-joint box generator. And the best of the best was to be found, drumroll please, on Hackaday.io. [Florian Festi]’s boxes.py not only has a sweet web interface, covers an absurd number of box styles, and includes kerf tests to ensure that your joints are tight, but it’s also written in easy-to-extend Python for when you have really particular needs.
Each of the box designs is fully customizable, so it’s easy to make something like a box with customized dividers, where the different compartments are specified in a sweet text markup. [Florian]’s example box set for the game Agricola is amazing.
Underpinning the code is a LOGO-like finger-joint drawing routine. This makes it relatively easy to draw your own funny shapes, and have the hard work of thinking through the joining fingers taken care of by the computer. [Florian] seems open to taking pull requests for new box shapes, but I haven’t thought of one yet.
I can’t say enough about how cool boxes.py is, and most of the demo applications are worth a look on their own. This was an entry in the Hackaday Prize back in 2017, and it’s been growing and improving ever since. Way to go, [Florian] and Co.
For 3D printers that aren’t already enclosed, why is easily adding a cheap and effective enclosure still not a completely solved problem? The reason is simple: unless one’s needs are very basic, enclosures are more than just boxes.
Different people need different features, printers come in different shapes and sizes, and creating something that can be both manufactured and shipped cheaply is a challenge in itself. In this article I’ll explain how those things make boxing up your printer a tougher nut to crack then may seem at first glance.
Enclosures Have Different Jobs
People have different expectations of what an enclosure’s job should be, and that determines which features are important to them and which are not. Here is a list of meaningful features for 3D printer enclosures; not everything on this list is important to everyone, but everything on this list is important to someone. Continue reading “3D Printering: Why Aren’t Enclosures Easier?”→
3D printing can be great for making enclosures, and following some simple guidelines can help the whole process go much smoother. 3D Hubs has an article on designing printed enclosures that has clear steps and tips to get enclosures coming out right the first time. 3D Hubs offers 3D printing and other services, and the article starts with a short roundup of fabrication methods but the rest is a solid set of tips applicable to anyone.
The first recommendation is to model the contents of the enclosure as a way to help ensure everything fits as it should, and try to discover problems as early as possible during the design phase, before anything gets actually printed. We’ve seen how a PCB that doesn’t take the enclosure into account risks needing a redesign, because there are some issues an enclosure just can’t fix.
The rest of their advice boils down to concrete design guidelines about wall thickness (they recommend 2 mm or more), clearances (allow a minimum of 0.5 mm between internal components and enclosure), and how to size holes for fasteners, clips, or ports. These numbers aren’t absolute minimums, but good baseline values to avoid surprises.
One final useful tip is that using a uniform wall thickness throughout the enclosure is general good practice. While this isn’t strictly necessary for successful 3D printing, it will make life easier if the enclosure ever moves to injection molding. Want to know more? Our own Bob Baddeley has an excellent primer on injection molding, and his been-there-done-that perspective is invaluable.
A wall-mounted, electric car charging station doesn’t sound like it’d require the most exciting or complicated enclosure. This was pretty much the assumption [Mastro Gippo] and his team started out with when they decided to turn what came back from a product designer into a real enclosure for the ‘Prism’ charging hardware they had developed. As it turned out, the enclosure proved to be the most challenging part of the project.
The first thought was to make a cheap, simple prototype enclosure for integration testing. This led them through trying out FDM 3D printed enclosures, wooden enclosures, folded (glued) plastic enclosures, aluminium extruded enclosures, Zamac alloy enclosures, and finally the plastic injection molded enclosure they had been avoiding due to the high costs.
Even if it meant taking out a loan to cover the setup costs, the results really do speak for themselves with a well-integrated design and two really happy looking partners-in-business. It does make us wonder how projects lacking this kind of financial leeway can get professional-grade enclosures without breaking the proverbial bank.
FDM 3D printing is always getting better and with a lot of post-processing you can have one enclosure that looks great, but that doesn’t scale. Outsourcing it to a professional 3D printing company like Shapeways is better, but it’s still not injection-molding quality and if the product is successful you’ll eventually invert the cost/benefit you were shooting for in the first place. Where is the middle ground on great-looking enclosures? Please let us know your experiences and thoughts in the comments.
Hackaday is all about the neat hacks and the repurposing of old components into new projects, but many people then try to take those projects and turn them into businesses. We’ve seen lots of people offer their stuff as kits and sell them on Tindie, with the rare few going on to develop a consumer electronic product at scale.
The Hackaday Prize 2017 Best Product highlights this journey. “Scale” itself is a vague term, but essentially it means to be able to produce enough to meet market demand. We hope that market demand is roughly 7 billion units, purchasing yearly, but the reality is that it is somewhere between 1 and a few hundred thousand, with very big differences in manufacturing at each order of magnitude. So how do you start with a proof of concept and design your product from the very beginning to be optimized to scale to meet whatever demand you can handle?
Having finished the Tools of the Trade series on circuit board assembly, let’s look at some of the common methods for doing enclosures. First, and possibly the most common, is injection molding. This is the process of taking hot plastic, squirting it through a small hole and into a cavity, letting it cool, and then removing the hardened plastic formed in the shape of the cavity.
The machine itself has three major parts; the hopper, the screw, and the mold. The hopper is where the plastic pellets are dumped in. These pellets are tiny flecks of plastic, and if the product is to be colored there will be colorant pellets added at some ratio. The hopper will also usually have a dehumidifier attached to it to remove as much water from the pellets as possible. Water screws up the process because it vaporizes and creates little air bubbles.
Next the plastic flecks go into one end of the screw. The screw’s job is to turn slowly, forcing the plastic into ever smaller channels as it goes through a heating element, mixing the melted plastic with the colorant and getting consistent coloring, temperature, and ever increasing pressure. By the time the plastic is coming out the other end of the screw, and with the assistance of a hydraulic jack, it can be at hundreds of tons of pressure.
Finally, the plastic enters the mold, where it flows through channels into the empty cavity, and allowed to sit briefly to cool. The mold then separates and ejector pins push the part out of the cavity.
There was a time when building something yourself probably meant it didn’t look very much like a commercial product. That’s not always a bad thing. We’ve seen many custom builds that are nearly works of art. We’ve also seen plenty of builds that are–ahem–let’s say were “hacker chic”.
[AlexanderBrevig] decided to take on a project using a PSoC development board he picked up. In particular, he wanted to build a custom game keypad. He prototyped a number of switches with the board and got the firmware working so that the device looks like a USB HID keyboard.