A Nicely Accurate PCB Drill Press You Can Build Yourself

May 25, 2022 by Zoe Skyforest 6 Comments

Making PCBs isn’t always just about getting nice copper traces on a lovely fiberglass board. There’s often lots of drilling to be done! This PCB drill press from [w_k_fay] should help you do just that with the finesse and accuracy of a pro.

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.

The total build came in at under $50 spend by the time [w_k_fay] was done. Alternatively, you could use this 3D printed design to build your own as well. If you’ve been whipping up your own useful tools for the home shop, though, don’t hesitate to drop us a line!

TurtleAuth DIY Security Token Gets (Re)designed For Durable, Everyday Use

May 21, 2022 by Donald Papp 15 Comments

[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.

Making enclosures from PCB material can really hit the spot, and there’s no need to re-invent the wheel when it comes to doing so. Our own [Voja Antonic] laid out everything one needs to know about how to build functional and beautiful enclosures in this way.

KiCAD Plugin Gives Your PCBs That Handmade Look

April 17, 2022 by Al Williams 29 Comments

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.

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Best Ways To Make PCB Breakaway Tabs, Revealed

April 9, 2022 by Donald Papp 20 Comments

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.

How Small Is Too Small?

March 5, 2022 by Elliot Williams 29 Comments

Not a rhetorical question! This week we consider the most micro microcontroller: the HC32L110. It’s the new title holder of the smallest ARM Cortex M0+ part. But could you actually use it?

MCU is the black thing that’s smaller than the capacitor.

I remember way back, when I first learned to solder surface-mount components. It was fiddly at first, but nowadays I don’t use through-hole components unless someone’s twisting my arm. And I still do my soldering myself — down to 0603 really isn’t all that bad with an iron, and below that, there’s always the heat plate. My heat plate has also gotten me through the two times I’ve actually needed to put down a ball-grid-array part. It wasn’t as bad as I had feared, honestly.

So maybe it’s time for me to take the BGA plunge and design a board or two just to get more familiar with the tech. I probably won’t dive straight into the deep end, like the featured chip here with 0.35 mm ball pitch, but rather stick with something that the cheap PCB services can easily handle. My experience tells me that the best way to learn something is just to test it out.

Now, off to go part shopping in the middle of a chip crisis! Wish me luck.

Backpack Board For OLEDs Boasts Fancy Features

February 14, 2022 by Donald Papp 6 Comments

Back when LCD character displays based on the HD44780 controller were the bee’s knees, a way to make them easier to work with came in the form of “backpack” PCBs, which provided an accessible serial interface and superior display handling at the same time. [Barbouri] has updated that idea with a backpack board that mounts to OLED displays using the US2066 display driver, and provides an I²C interface with powerful and convenient high-level functions that make the display simple to use.

On the software side, the backpack uses this I2cCharDisplay driver project which provides functions like cursor control, fading, display shifting, and of course writing characters or strings. While [Barbouri] designed the board specifically to accommodate Newhaven Slim Character OLED displays, it should in theory work with any US2066-based OLED character display. [Barbouri]’s design files for the Slim-OLED Display backpack board are available for download directly from the project page (link is near the bottom), or boards can be purchased directly from OSH Park.

OLED technology is nifty as heck; we’ve seen some neat tricks done by stacking transparent OLED displays, and even seen OLEDs made in the home lab.

Pick And Place Hack Chat

February 7, 2022 by Dan Maloney No comments

Join us on Wednesday, February 9 at noon Pacific for the Pick and Place Hack Chat with Chris Denney!

We in the hacker trade are pretty used to miracles — we make them all the time. But even the most jaded among us has to admit that modern PCB assembly, where components that could easily hide under a grain of sand are handled by robots, borders on witchcraft. The pick and place machines that work these wonders not only have to hit their marks accurately and precisely, but they also do it at blinding speeds and for days on end.

Luckily, even those of us who design circuits for a living and depend on PCB assembly services to realize those designs can, at least to some degree, abstract the details of the pick and place phase of the process away. But making it “just work” isn’t a trivial task, and learning a little bit about what it takes to do so can make us better designers. Plus, it’s just plain cool to watch a pick and place do its thing. And to dive a little deeper into pick and place, Chris Denney, CTO of Worthington Assembly and co-host of “Pick, Place, Podcast” will stop by the Hack Chat. If you’ve ever wondered about the inner workings of PCB assembly and the role pick and place plays in it, or if you’re looking for tips on how to optimize your layouts for pick and place, this is one you won’t want to miss!

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, February 9 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

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