3D-Printed Tooling Enables DIY Electrochemical Machining

When it comes to turning a raw block of metal into a useful part, most processes are pretty dramatic. Sharp and tough tools are slammed into raw stock to remove tiny bits at a time, releasing the part trapped within. It doesn’t always have to be quite so violent though, as these experiments in electrochemical machining suggest.

Electrochemical machining, or ECM, is not to be confused with electrical discharge machining, or EDM. While similar, ECM is a much tamer process. Where EDM relies on a powerful electric arc between the tool and the work to erode material in a dielectric fluid, ECM is much more like electrolysis in reverse. In ECM, a workpiece and custom tool are placed in an electrolyte bath and wired to a power source; the workpiece is the anode while the tool is the cathode, and the flow of charged electrolyte through the tool ionizes the workpiece, slowly eroding it.

The trick — and expense — of ECM is generally in making the tooling, which can be extremely complicated. For his experiments, [Amos] took the shortcut of 3D-printing his tool — he chose [Suzanne] the Blender monkey — and then copper plating it, to make it conductive. Attached to the remains of a RepRap for Z-axis control and kitted out with tanks and pumps to keep the electrolyte flowing, the rig worked surprisingly well, leaving a recognizably simian faceprint on a block of steel.

[Amos] admits the setup is far from optimized; the loop controlling the distance between workpiece and tool isn’t closed yet, for instance. Still, for initial experiments, the results are very encouraging, and we like the idea of 3D-printing tools for this process. Given his previous success straightening his own teeth or 3D-printing glass, we expect he’ll get this fully sorted soon enough.

Scanning Medium Format Film On A 35mm Scanner

Scanning film is great for archival purposes as well as sharing said photos digitally. However, if you’re scanning 120 film, aka medium format, it can be expensive to get the requisite hardware. 35mm scanners are comparatively more common, so [Christian Chapman] decided to modify one to suit medium film instead.

The hack is for the Plustek 8100, and requires modifying the scanner in two ways. Firstly, the driver has to be scanned to sweep a longer range to take into account the bigger film. Secondly, a part of the film carriage has to be replaced so it doesn’t show up in the scanners field of view.

The former is achieved by using the sane-genesys scanner software backend, which can be easily modified to adjust the scan length values appropriately. The latter is achieved via 3D printing replacement components that fit without blocking the requisite area.

It’s a tidy hack and one that allows [Christian] to both scan medium format film as well as overscan 35mm film to capture details from the sprocket hole area. We’ve seen fully custom film scanner builds before, too. If you’ve built your own scanner, be sure to drop us a line!

Emulating The IBM PC On An ESP32

The IBM PC spawned the basic architecture that grew into the dominant Wintel platform we know today. Once heavy, cumbersome and power thirsty, it’s a machine that you can now emulate on a single board with a cheap commodity microcontroller. That’s thanks to work from [Fabrizio Di Vittorio], who has shared a how-to on Youtube. 

The full playlist is quite something to watch, showing off a huge number of old-school PC applications and games running on the platform. There’s QBASIC, FreeDOS, Windows 3.0, and yes, of course, Flight Simulator. The latter game was actually considered somewhat of a de facto standard for PC compatibility in the 1980s, so the fact that the ESP32 can run it with [Fabrizio’s] code suggests he’s done well.

It’s amazingly complete, with the ESP32 handling everything from audio and video to sound output and keyboard and mouse inputs. It’s a testament to the capability of modern microcontrollers that this is such a simple feat in 2021.

We’ve seen the ESP32 emulate 8-bit gaming systems before, too. If you remember [Fabrizio’s] name, it’s probably from his excellent FabGL library. Videos after the break. Continue reading “Emulating The IBM PC On An ESP32”

Rooting The Atari VCS 800

The Atari VCS 800 is a modern product, a hybrid of a PC and a games console. Fundamentally, its a bunch of modern chips in a box running Linux that will let you browse the web or emulate some old games. Now, thanks to [ArcadeHustle], you can have persistent root access to the VCS 800 at your leisure.

The trick is simple, and begins by interrupting the systemd startup scripts on boot. One can then merge files into the /etc directory to achieve root access, either by the tty terminal or over TCP. It’s all wrapped up in the script available at the Github link above.

You can actually run a variety of OSs on the hardware, as it’s powered by an AMD Ryzen R1606G CPU and runs straightforward PC architecture. However, if you want to customize the existing OS to do your bidding, this hack is the way to go.

Hacking to get root access is key if you want to get anywhere with a system. We’ve seen it done on thin clients as well as car infotainment systems to give the owner full control over the hardware they own. If you’ve got your own root exploit you’d like to share, do drop us a line, won’t you?


Black And White TV Was Hiding A Special Input Board

[John Floren] found a nice old black & white TV in a thrift store, and as so many of us would, he decided to take it home. He was surprised upon getting it there that it had, in addition to the VHF and UHF antenna inputs, a mysterious extra connector on the back. Naturally, he set about investigating.

On the rear was an obviously hacked-in F-type connector, paired with a toggle switch, both unlabelled. Running the output of an RF modulator to the connector didn’t net an image on the screen, even though the same method worked when hooked up to the antenna inputs. Undeterred, [John] dug deeper.

Inside, a little PCB bearing the mark “TVM.04” was inside, bearing a handful of components. The device turned out to be a Pickes and Trout TVM-04 adapter, designed in the 1970s for hooking a computer up to a television for use as a monitor. The adapter board allows the Hitachi TV to accept a composite video input. [John] was able to test the TV with a NES clone outputting composite video and voila, it worked! [John] then went further, adding an audio input and installing standard RCA jacks to make it easier to use the input with more modern electronics.

It’s a great example of how simply opening up some electronics and poking around can teach you something. Hacking on old-school TVs is a popular pastime around these parts, it seems. If you’ve been working on your own retro display hack, be sure to let us know.

Building An Electronic Tester For Measuring Arrow Stiffness

When shooting archery, if you want to be accurate, you need arrows of uniform specification and quality. One important part of this is making sure each arrow has a spine of similar stiffness. Traditionally, this is checked in a very analog way by using weights and measuring deflection of the arrow spine, but it can be done electronically too with this tester from [dvd8n].

The principle of operation is simple. The arrow is held up by two supports, 28 inches apart. The user then presses down in the center of the arrow, deflecting it by a 1/2 inch where itreaches a stop , and load cells at either end of the tester measure the force required to deflect the arrow by the set amount.

It allows arrows to be electronically measured in a fashion that is compatible with existing standards for measurement. The Arduino hardware which measures the load cells can also easily run conversion maths to display the arrow’s measured stiffness in whatever common spine measurement standard is desired. The system can also weigh the arrows, a useful thing to know for the home fletcher.

It’s a tidy build and one that should prove useful when [dvd8n] is building out their next quiver. We’ve seen other capable DIY archery hacks before, too. If you’ve got your own, drop us a line!


A Simple Sun Tracker With Very Few Parts

There are a huge number of ways to track the sun if you have some reason to do so. You can use time-based algorithms, or feed in coordinates from the Internet, or you could do it with minimal parts and no electronic processing at all. The latter is how this project from [3D Printer Academy] works. 

One key thing about this project is that you shouldn’t be fooled by the solar panels. They’re not here to generate power for external use. Instead, they’re wired up in opposing polarities to a DC gear motor. The motor turns the panel assembly. As one panel is hit by the sun, it turns the assembly to bring the other panel into the sun as well simply by applying a DC voltage to the motor. The other panel is wired up the opposite way, so if it is in the sun, it brings the other panel into alignment as well.

This serves as a very simple planar solar tracker. If you want to track the sun with minimal parts, this is a very easy way to do it. You’ll just need to put whatever you want to actually aim at the sun on top of the assembly. if that happens to be a larger solar panel, it may be cumbersome and another more complex design may be more suitable.

It’s an ingenious and easy way of tracking the sun, even if it’s not immediately apparent how the device would be useful in its current form. If you’ve got an idea how you would use such a mechanism, let us know in the comments.

We’ve seen other solar tracker projects before, too. Video after the break.

Continue reading “A Simple Sun Tracker With Very Few Parts”