When you’re working with PCBs and making single units to knock out in those Chinese fabs, going from layout to manufacturable Gerber files is just a few button presses, no matter what PCB layout tool you prefer. But, once you get into producing sets of PCBs that form a larger system, or are making multiple copies for efficient manufacturing, then you’re not going to get far without delving into the art of PCB panelization. We’ve seen a few options over the years, and here’s yet another one that’s looking quite promising — hm-panelizer by [halfmarble] is a cross platform Python GUI application, which leverages Kivy, so it should run on pretty well on most major platforms without too much hassle. The tool is early in development, so is restricted to handling only straight PCB edges, with horizontal mouse-bites for now, but we’re sure it will quickly grow more general purpose capabilities given time and support.
In an ideal world, open source tools like KiCAD would have a built-in panelizer, but for now we can dream and hm-panelizer might just be good enough for some people. For more choices on panelizing, checkout our guide to making it easy, and just to muddy the waters here’s another way to do it.
Keyboards with wells like the Maltron, the Kinesis Advantage family, and everything dactyl-esque out there are great. Trust us, we know this firsthand. But if you want to build your own curvy girl, how the heck can you implement that shape without 3D printing, clever woodworking, or access to tooling and plastic molding equipment? Well, there is another way. Over on twitter (translated) (Threadreader: Japanese, English), [tsukasa_metam] has achieved the key well effect by stacking up PCBs to create a skyline of vertically-staggered keys.
The boards of Cityscape are all screwed together for mechanical integrity, but those screws are working overtime, providing electrical connections between the layers as well. We particularly like that there is an impetus for this build other than ‘I thought of it, so let’s do it’ — [tsukasa_metam] tends to typo in the double key press sense, hitting Q for instance at the same time when A was the intended target. Between the 3.2 mm of key travel, the 2.8 mm step height, and those flat F10 keycaps, that is no longer an issue.
Instead of the popular low-profile Kailh choc switches, [tsukasa_metam] went with TTC KS32s, a new switch introduced in 2020. Unlike chocs, they’ll take Cherry MX-style keycaps, as long as they’re wearing short skirts. Cityscape isn’t totally open source, but the idea is now out there nonetheless, and we happen to have an Odd Inputs and Peculiar Peripherals contest running now through July 4th.
Plenty of gamers around these parts require an expensive PC to play games, often spending thousands of dollars for a gaming machine. Believe it or not, though, there are entire classes of games that don’t require any electronics at all, but that doesn’t mean that they don’t benefit from the addition of some neat gadgets. This Settlers of Catan game uses custom LCD tiles with a built-in custom mesh network.
The tiles for the game board themselves are hexagonal and snap together using magnetic pogo pins in order to form a board of any size or shape. The pogo pins also allow communication for a pseudo-mesh network to operate with each tile’s built-in PCB to allow the game board to know exactly which tiles are placed where and to display the correct image on each one. Each tile contains it own RP2040 microcontroller, keeping the overall cost of each tile to a minimum.
For those regularly hosting game night, a project like this could really change the traditionally analog game’s dynamic for the better. It was mostly a project that [Colin Iuliano] built just for fun, and if he ever builds a second one he does plan on some improvements, but we’d say that it looks like a success already. For other Catan-based electronic design inspiration, take a look at this complete and non-modular electronic game board.
The design isn’t particularly fancy or pretty, but just simply focuses on doing a simple job well. There’s a basic DC motor, sitting on a linear rail so that it has minimal deflection in the X and Y axes as it moves up and down. Special care was taken to ensure the linear rail was mounted perfectly perpendicular to the base to ensure the drill doesn’t wander or splay off target.
A collet chuck is used to center the bit as well as possible for a good price. The build also includes a bright LED in order to give you the best possible view of your work. Power is via a variable bench supply which allows for variable speed as necessary. There’s a foot pedal to activate the drill which allows both hands to be used for positioning the work for added ease of use.
[Samuel]’s first foray into making DIY hardware authentication tokens was a great success, but he soon realized that a device intended for everyday carry and use has a few different problems to solve, compared to a PCB that lives and works on a workbench. This led to TurtleAuth 2.1, redesigned for everyday use and lucky for us all, he goes into detail on all the challenges and solutions he faced.
When we covered the original TurtleAuth DIY security token, everything worked fantastically. However, the PCB layout had a few issues that became apparent after a year or so of daily use. Rather than 3D print an enclosure and call it done, [Samuel] decided to try a different idea and craft an enclosure from the PCB layers themselves.
The three-layered PCB sandwich keeps components sealed away and protected, while also providing a nice big touch-sensitive pad on the top, flanked by status LEDs. Space was a real constraint, and required a PCB redesign as well as moving to 0402 sized components, but in the end he made it work. As for being able to see the LEDs while not having any component exposed? No problem there; [Samuel] simply filled in the holes over the status LEDs with some hot glue, creating a cheap, effective, and highly durable diffuser that also sealed away the internals.
The first PCBs we built involved a draftsman laying out large pieces of tape. The finished artwork would be photographically reduced to produce the board. This solved a few problems. It was easier to work on the large pieces and any errors were reduced by the scale amount. Boards from this era have a distinct appearance because the tracks are generally curved. But when computer-aided drafting took over, the early packages couldn’t deal with wavy lines making all sorts of angles. So traces started appearing at very common angles like 45 degrees or 90 degrees only. If you use KiCAD, though, there’s no reason to have rectilinear traces. Now there is a plugin to help make your boards appear like old-fashioned circuit boards.
The video by [mitxela] below talks about how we got here and debunks some common myths about PCB design. The plugin produces rounded corners and teardrop-shaped pads. There’s also a second post on the topic with more details. The effect isn’t just ornamental. There are some reasons graceful traces might be better than sharp angles.
Most of us are familiar with the concept of producing PCBs in a panel, and snapping them apart afterwards. V-grooves that go most of the way through a PCB are one way to go about this, but a line of perforations along which to snap a tab is another. But what’s the best size and spacing of holes to use? Sparkfun’s [Nick Poole] spent some $400 on PCBs to get some solid answers by snapping each of them apart, and judging the results.
The nice thing about creating a perforation line (or “mouse bites”) is that drill hits are a very normal thing in PCB production, which makes creating this kind of breakaway tab a very straightforward and flexible method. However, it can be tricky to get results that are just right. Too sturdy, and breaking apart is a hassle. Too weak, and the board may break or twist before its time. On top of that, edges must also break cleanly. We’ve covered panelizing PCBs in this way before, but this is the first time we’ve seen someone seriously look into how to create optimal breakaway tabs.
Placing holes tangent to the board edge (as shown above) isn’t the prettiest, but keeps PCB edges free from protrusions. This is best for boards that are rail-mounted, or have tight enclosures.
Data on designing mouse bites was sparse and a bit inconsistent, so [Nick] decided to figure it out empirically and share the results. The full details are available in Building a Better Mousebite (PDF download) but the essence of the recommendations are: 0.015″ unplated holes, spaced 0.025″ apart (center-to-center), tabs a maximum of 0.118″ wide (so as to be compatible with depanelizing tools), and holes that extend into the corners of the breakaway tab to avoid sharp edges. Holes should be placed slightly differently depending on whether one wishes to optimize the cosmetic appearance versus the physical smoothness of the board edge, but those numbers are the core of the guidelines.
To fine tune, [Nick] suggests increasing the spacing between holes to add strength, or just adding additional tabs. What about thickness of PCB? [Nick] tested boards both 0.8 mm and 1.6 mm thick, and while different amounts of torque were needed to snap the boards apart, things still worked as expected regardless of PCB thickness.
When it comes down to it, the best numbers will ultimately be the ones that your process or fab house can most efficiently handle, but [Nick]’s numbers should not steer anyone wrong, and it’s fantastic to see this kind of work go into refining such a common PCB feature.
