Most of the time, designing a printed circuit board is a little like one of those problems in an introductory physics course, the ones where you can safely ignore things like air resistance. With PCBs, it’s generally safe to ignore things like trace heating and other thermal considerations in favor of just getting everything placed sensibly and routing all the traces neatly.
But eventually, the laws of physics catch up to you, and you’ll come across a real-world problem where you can’t just hand-wave thermal considerations aside. When that happens, you’ll want to have a really good idea of just how much a trace is going to heat up, and what it’s going to do to the performance of your board, or even if the PCB is going to survive the ordeal.
Digging into the thermal properties of PCBs is something that Mike Jouppi has been doing for years. After working in the aircraft industry as a mechanical engineer, he started Thermal Management LLC, which developed software to make the thermal design of PCBs easier. He’ll stop by the Hack Chat to answer your questions about PCB thermal design considerations, and help us keep all our hard work from going up in smoke.
Remember that time back in 2021 when a huge container ship blocked the Suez Canal and disrupted world shipping for a week? Well, something a little like that is playing out again, this time in the Chesapeake Bay outside of the Port of Baltimore, where the MV Ever Forward ran aground over a week ago as it was headed out to sea. Luckily, the mammoth container ship isn’t in quite as narrow a space as her canal-occluding sister ship Ever Given was last year, so traffic isn’t nearly as impacted. But the recovery operation is causing a stir, and refloating a ship that was drawing 13 meters when it strayed from the shipping channel into a muddy-bottomed area that’s only about 6 meters deep is going to be quite a feat of marine engineering. Merchant Marine YouTuber Chief MAKOi has a good rundown of what’s going on, and what will be required to get the ship moving again.
With the pace of deep-space exploration increasing dramatically of late, and with a full slate of missions planned for the future, it was good news to hear that NASA added another antenna to its Deep Space Network. The huge dish antenna, dubbed DSS-53, is the fourteenth dish in the DSN network, which spans three sites: Goldstone in California; outside of Canberra in Australia; and in Madrid, where the new dish was installed. The 34-meter dish will add 8% more capacity to the network; that may not sound like much, but with the DSN currently supporting 40 missions and with close to that number of missions planned, every little bit counts. We find the DSN fascinating, enough so that we did an article on the system a few years ago. We also love the insider’s scoop on DSN operations that @Richard Stephenson, one of the Canberra operators, provides.
Does anybody know what’s up with Benchy? We got a tip the other day that the trusty benchmarking tugboat model has gone missing from several sites. It sure looks like Sketchfab and Thingiverse have deleted their Benchy files, while other sites still seem to allow access. We poked around a bit but couldn’t get a clear picture of what’s going on, if anything. If anyone has information, let us know in the comments. We sure hope this isn’t some kind of intellectual property thing, where you’re going to have to cough up money to print a Benchy.
Speaking of IP protections, if you’ve ever wondered how far a company will go to enforce its position, look no further than Andrew Zonenberg’s “teardown” of an anti-counterfeiting label that Hewlett Packard uses on their ink cartridges. There’s a dizzying array of technologies embedded inside what appears to be a simple label. In addition to the standard stuff, like the little cuts that make it difficult to peel a tag off one item and place it on another — commonly used to thwart “price swapping” retail thefts — there’s an almost holographic area of the label. Zooming in with a microscope, the color-shifting image appears to be made from tiny hexagonal cells that almost look like the pixels in an e-ink display. Zooming in even further, the pixels offer an even bigger (smaller) surprise. Take a look, and marvel at the effort involved in making sure you pay top dollar for printer ink.
And finally, we got a tip a couple of weeks ago on a video about jerry cans. If that sounds boring, stop reading right now — this one won’t reach you. But if you’re even marginally interested in engineering design and military history, make sure you watch this video. What is now known to the US military as “Can, Gasoline, Military 5-Gallon (S/S by MIL-C-53109)” and colloquially known as the NATO jerry can, started life as the Wehrmacht-Einheitskanister, a 20-liter jug whose design addresses a long list of specifications, from the amount of liquid it could contain to how the cans would be carried. The original could serve as a master class in good design, and some of the jugs that were built in the 1940s are still in service and actively sought by collectors of militaria. Cheap knockoffs are out there, of course, but after watching this video, we’ve developed a taste for jerry cans that only the original will sate.
Thermal receipt printers are finding their way into all sorts of projects that are well beyond the point-of-sale environment that they normally inhabit. And while we applaud all the creative and artistic uses hackers have found for these little gems, this GitHub physical ticket printer has to be the best use for one yet.
According to [Andrew Schmelyun], seeing a fast-food order pop up on a thermal printer was the inspiration for this build. Maintaining over one hundred GitHub repos as he does, it’s easy for the details of any one bug report or feature request to get lost in the swarm of sticky notes that [Andrew] previously used to keep track of his work. To make it happen, he teamed an Epson thermal printer up to a Raspberry Pi Zero W and worked out the details of sending data to the printer using PHP. Luckily, there’s a library for that — the beauty of GitHub.
With the “Hello, World!” bit out of the way, [Andrew] turned his attention to connecting to GitHub. He set up some webhooks on the GitHub side to send a POST request every time an issue is reported on one of his repos. The POSTs are sent via ngrok to a PHP web server running on the Pi, which formats the data and sends the text to the printer. There’s a short video in the tweet below.
Between the sound of the printer working and the actual dead-tree ticket, it’ll be hard for [Andrew] to miss issues now. We’ve seen thermal printers stuffed into cameras, used to send pictures to Grannie, and even watched them commit suicide slowly, but we say hats off to [Andrew] for his solid work ethic and a fun new way to put a receipt printer to use.
Join Hackaday Editor-in-Chief Elliot Williams and Staff Writer Dan Maloney for an audio tour of the week’s top stories and best hacks. We’ll look at squeezing the most out of a coin cell, taking the first steps towards DIY MEMS fabrication, and seeing if there’s any chance that an 80’s-vintage minicomputer might ride again. How small is too small when it comes to chip packages? We’ll find out, and discover the new spectator sport of microsoldering while we’re at it. Find out what’s involved in getting a real dead-tree book published, and watch a hacker take revenge on a proprietary memory format — and a continuous glucose monitor, too.
Back in grad school, we biology students were talking shop at lunch one day. We “lab rats” were talking about the tools of the trade, which for most of us included things like gel electrophoresis, restriction endonucleases, and polymerase chain reaction. Not to be left out, a fellow who studied fire ants chimed in that his main tool was a lawn chair, which he set up by a Dumpster in a convenience store parking lot to watch a fire ant colony. Such is the glamor of field biology.
Ants on the march. Tough luck for the crickets, though.
What our colleague [Mike] wouldn’t have given for something like PiSpy, the automated observation tool for organismal biology by [Greg Pask] of Middlebury College, et al. As discussed in the preprint abstract, an automated imaging platform can be key to accurate observations of some organisms, whose behavior might be influenced by the presence of a human observer, or even a grad student in a lawn chair. Plus, PiSpy offers all the usual benefits of automation — it doesn’t get tired, it doesn’t need to take bathroom breaks, and it can even work around the clock. PiSpy is based on commonly available components, like laser-cut plywood and a Raspberry Pi and camera, so it has the added advantage of being cheap and easy to produce — or at least it will be when the Pi supply picks back up again. PiSpy takes advantage of the Pi’s GPIO pins to enable triggering based on external events, or controlling peripherals like lights or servos.
While built for biological research, there are probably dozens of uses for something like PiSpy. It could be handy for monitoring mechanical testing setups, or perhaps for capturing UI changes during embedded device development. Or you could just use it to watch birds at a feeder. The source is all open-sourced, so whatever you make of PiSpy is up to you — even if it’s not for watching fire ants.
Here’s a little eye-opener for you: next time you’re taking a walk, cast your eyes to the ground for a bit and see how far you can go without spotting a carelessly discarded face mask. In our experience, it’s no more than a block or two, especially if you live near a school. Masks and other disposal artifacts of the COVID-19 pandemic have turned into a menace, and uncounted billions of the things will be clogging up landfills, waterways, and byways for decades to come.
Unless they can be recycled into something useful, of course, like the plastic cases used for rapid antigen tests. This comes to us by way of [Ric Real] from the Design and Manufacturing Futures lab at the University of Bristol in the UK. If any of this sounds or looks familiar, refer back to October when the same team presented a method for turning old masks into 3D printer filament. The current work is an extension of that, but feeds the polypropylene pellets recovered from the old masks into a desktop injection molding machine.
The injection molding machine is fitted with 3D-printed molds for the shells of lateral flow devices (LFD) used for COVID-19 rapid antigen testing. The mold tooling was designed in Fusion 360 and printed on an Elegoo Mars MSLA printer using a high-strength, temperature-resistant resin. The molds stood up to the manual injection molding process pretty well, making good-quality parts in the familiar blue and white colors of the starting material. It’s obviously a proof of concept, but it’s good to see someone putting some thought into what we can do with the megatonnes of plastic waste generated by the pandemic response.
What does it take to make your own integrated circuits at home? It’s a question that relatively few intrepid hackers have tried to answer, and the answer is usually something along the lines of “a lot of second-hand equipment.” But it doesn’t all have to be cast-offs from a semiconductor fab, as [Zachary Tong] shows us with his homebrew direct laser lithography setup.
Most of us are familiar with masked photolithography thanks to the age-old process of making PCBs using photoresist — a copper-clad board is treated with a photopolymer, a mask containing the traces to be etched is applied, and the board is exposed to UV light, which selectively hardens the resist layer before etching. [Zach] explores a variation on that theme — maskless photolithography — as well as scaling it down considerably with this rig. An optical bench focuses and directs a UV laser into a galvanometer that was salvaged from an old laser printer. The galvo controls the position of the collimated laser beam very precisely before focusing it on a microscope that greatly narrows its field. The laser dances over the surface of a silicon wafer covered with photoresist, where it etches away the resist, making the silicon ready for etching and further processing.
Being made as it is from salvaged components, aluminum extrusion, and 3D-printed parts, [Zach]’s setup is far from optimal. But he was able to get some pretty impressive results, with features down to 7 microns. There’s plenty of room for optimization, of course, including better galvanometers and a less ad hoc optical setup, but we’re keen to see where this goes. [Zach] says one of his goals is homebrew microelectromechanical systems (MEMS), so we’re looking forward to that.
Digging into the thermal properties of PCBs is something that Mike Jouppi has been doing for years. After working in the aircraft industry as a mechanical engineer, he started Thermal Management LLC, which developed software to make the thermal design of PCBs easier. He’ll stop by the Hack Chat to answer your questions about PCB thermal design considerations, and help us keep all our hard work from going up in smoke.
