Electromagnets Make Vertical CNC Cutter A Little Stickier

April 12, 2024 by 12 Comments

Workholding is generally not a problem on a big CNC plasma cutter.; gravity does a pretty good job of keeping heavy sheet steel in place on the bed. But what if your CNC table isn’t a table? The answer: magnets — lots of magnets.

The backstory on this is a bit involved, but the condensed version is that [Lucas] needed a CNC plasma cutter big enough to cut full-sized sheets of steel, but lacked the floor space in his shop for such a beast. His solution was to build a custom CNC machine that stands more or less vertically, allowing him to cut full sheets in a mere fraction of the floor space. It’s a fantastic idea, one that he put a lot of effort into, but it’s not without its problems. Chief among them is the tendency for the sheet metal to buckle and bulge during cutting since gravity isn’t working for him, along with the pesky problem of offcuts slipping away.

To help hold things in place, [Lucas] decided to magnetize the bed of his cutter. That required winding a bunch of magnets, which is covered in the video below. Mass production of magnets turns out not to be as easy as you’d think. Also unexpected was the need to turn off magnets when the cutting torch is nearby, lest the magnetic field bork the cutting plasma. [Lucas] grabbed some code from the LinuxCNC forum that streams the gantry coordinates over serial and used an Arduino to parse those messages. When the torch is getting close to one of the magnets, a relay board cuts power to just that magnet. You can see it in action in the video below; at around the 18:15 mark, you can see the sheet bulging up a bit when the torch comes by, and sucking back down when it moves on.

The amount of work [Lucas] put into this project is impressive, and the results are fantastic. This isn’t the first time he’s relied on the power of magnets to deal with sheet steel, and it probably won’t be the last.

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HDMI DDC Keypad Controls Monitor From Rack

April 12, 2024 by 22 Comments

Sometime last year, [Jon Petter Skagmo] bought a Dell U3421WE monitor. It’s really quite cool, with a KVM switch and picture-by-picture support for two inputs at the same time. The only downside is that control is limited to a tiny joystick hiding behind the bezel. It’s such a pain to use that [Jon] doesn’t even use all of the features available.

[Jon] tried ddcutil, but ultimately it didn’t work out. Enter the rack-mounted custom controller keyboard, a solution which gives [Jon] single keypress control of adjusting the brightness up and down, toggling picture-by-picture mode, changing source, and more.

How does it work? It uses the display data channel (DDC), which is an I²C bus on the monitor’s HDMI connector. More specifically, it has a PIC18 microcontroller sending those commands via eight Cherry MX-style blues.

Check this out — [Jon] isn’t even wasting one of the four monitor inputs because this build uses an HDMI through port. The finished build looks exquisite and fits right into the rack with its CNC-routed aluminium front panel. Be sure to check it out in action after the break.

Ever wonder how given keyboard registers the key you’re pressing? Here’s a brief history of keyboard encoding.

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Crank-Powered Train Uses No Batteries Or Plugs

April 12, 2024 by 5 Comments

The prolific [Peter Waldraff] is at back it with another gorgeous micro train layout. This time, there are no plugs and no batteries. And although it’s crank-powered, it can run on its own with the flip of a switch. How? With a supercapacitor, of course.

The crank handle is connected a 50 RPM motor that acts as a generator, producing the voltage necessary to both power the train and charge up the supercapacitor. As you’ll see in the video below, [Peter] only has to move the train back and forth about two or three times before he’s able to flip the switch and watch it run between the gem mine and the cliff by itself.

The supercapacitor also lights up the gem mine to show off the toiling dwarfs, and there’s a couple of reed switches at either end of the track and a relay that handles the auto-reverse capability. Be sure to stick around to the second half of the video where [Peter] shows how he built this entire thing — the box, the layout, and the circuit.

Want to see more of [Peter]’s trains and other work? Here you go.

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Hackaday Podcast Episode 266: A Writer’s Deck, Patching Your Battleship, And Fact-Checking The Eclipse

April 12, 2024 by No comments

Before Elliot Williams jumps on a train for Hackaday Europe, there was just enough time to meet up virtually with Tom Nardi to discuss their favorite hacks and stories from the previous week. This episode’s topics include the potential benefits of having a dual-gantry 3D printer, using microcontrollers to build bespoke note taking gadgets, the exciting world of rock tumbling, and the proper care and maintenance required to keep your World War II battleship in shape. They’ll also go over some old school keyboard technologies, DIP chip repairs, and documenting celestial events with your home solar array. By the end you’ll hear about the real-world challenges of putting artificial intelligence to work, and how you can safely put high-power lithium batteries to work in your projects without setting your house on fire.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

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Beating IBM’s Eagle Quantum Processor On An Ising Model With A Classical Tensor Network

April 12, 2024 by 8 Comments

The central selling point of qubit-based quantum processors is that they can supposedly solve certain types of tasks much faster than a classical computer. This comes however with the major complication of quantum computing being ‘noisy’, i.e. affected by outside influences. That this shouldn’t be a hindrance was the point of an article published last year by IBM researchers where they demonstrated a speed-up of a Trotterized time evolution of a 2D transverse-field Ising model on an IBM Eagle 127-qubit quantum processor, even with the error rate of today’s noisy quantum processors. Now, however, [Joseph Tindall] and colleagues have demonstrated with a recently published paper in Physics that they can beat the IBM quantum processor with a classical processor.

In the IBM paper by [Yougseok Kim] and colleagues as published in Nature, the essential take is that despite fault-tolerance heuristics being required with noisy quantum computers, this does not mean that there are no applications for such flawed quantum systems in computing, especially when scaling and speeding up quantum processors. In this particular experiment it concerns an Ising model, a statistical mechanical model, which has many applications in physics, neuroscience, etc., based around phase transitions.

Unlike the simulation running on the IBM system, the classical simulation only has to run once to get accurate results, which along with other optimizations still gives classical systems the lead. Until we develop quantum processors with built-in error-tolerance, of course.

This Week In Security: BatBadBut, DLink, And Your TV Too

April 12, 2024 by 23 Comments

So first up, we have BatBadBut, a pun based on the vulnerability being “about batch files and bad, but not the worst.” It’s a weird interaction between how Windows uses cmd.exe to execute batch files and how argument splitting and character escaping normally works. And what is apparently a documentation flaw in the Windows API.

When starting a process, even on Windows, the new executable is handed a set of arguments to parse. In Linux and friends, that is a pre-split list of arguments, the argv array. On Windows, it’s a single string, left up to the program to handle. The convention is to follow the same behavior as Linux, but the cmd.exe binary is a bit different. It uses the carrot ^ symbol instead of the backslash \ to escape special symbols, among other differences. The Rust devs took a look and decided that there are some cases where a given string just can’t be made safe for cmd.exe, and opted to just throw an error when a string met this criteria.

And that brings us to the big questions. Who’s fault is it, and how bad is it? I think there’s some shared blame here. The Microsoft documentation on CreateProcess() strongly suggests that it won’t execute a batch file without cmd.exe being explicitly called. On the other hand, This is established behavior, and scripting languages on Windows have to play the game by Microsoft’s rules. And the possible problem space is fairly narrow: Calling a batch file with untrusted arguments.

Almost all of the languages with this quirk have either released patches or documentation updates about the issue. There is a notable outlier, as the Java language will not receive a fix, not deeming it a vulnerability. It’s rather ironic, given that Java is probably the most likely language to actually find this problem in the wild. Continue reading “This Week In Security: BatBadBut, DLink, And Your TV Too” →

The Future Looks Bleak For Alexa Skill Development

April 12, 2024 by 30 Comments

While the average Hackaday reader is arguably less likely than most to install a megacorp’s listening device in their home, we know there’s at least some of you out there that have an Amazon hockey puck or two sitting on a shelf. The fact is, they offer some compelling possibilities for DIY automation, even if you do have to jump through a few uncomfortable hoops to bend them to your will.

That being said, we’re willing to bet very few readers have bothered installing more than a few Alexa Skills. But that’s not a judgment based on any kind of nerd stereotype — it’s just that nobody seems to care about them. A fact that’s evidenced by the recent revelation that even Amazon looks to be losing interest in the program. In a post on LinkedIn, Skill developer [Mark Tucker] shared an email he received from the mothership explaining they were ending the AWS Promotional Credits for Alexa (APCA) program on June 30th.

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