DJ Controller Modded For Better Scratching

April 18, 2026 by Zoe Skyforest No comments

[Jeremy Bell] loves scratching, but he had a problem. His Hercules DJ controller wasn’t really doing a great job at emulating the kind of action one would get with a real turntable. The solution was both mechanical and electronic in nature!

As stock, the Hercules MIDI rig lets you scratch in a relatively simplistic way. When it detects a finger touching the rotary control, it lets you scratch back and forth with great motion tracking. However, when you let go, playback resumes at regular speed instantaneously, which creates a somewhat inorganic sound.

The fix was to make some mechanical mods to the MIDI controller. [Jeremy] tried out a variety of different methods of using a motor to spin the rotary control continuously, from geared rigs to belt-driven setups. It was then possible to scratch on the controller, and then let it return to normal rotational speed, creating much smoother auditory transitions. However, this was imperfect, as for whatever reason, the Hercules rig would stop tracking the rotary control accurately unless it detected a finger was touching it. [Jeremy] worked around this by whipping up a slip-ring-like setup to keep his body permanently in contact with the rotary control even while spinning.

The results are pretty great—they’re both mechanically janky and fantastically satisfying to listen to. We’ve featured some other great DJ controller hacks over the years, like this sweet Pioneer UI upgrade.

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Electric Wind-Up Plane Uses Supercapacitors For Free Flight Fun

April 18, 2026 by Tyler August 1 Comment

There’s something to be said for a simple wind-up, free flight model airplane. With no controls, it must be built very well to fly well, and with only the limited power of a rubber band, it needs a good, high-lift design without much superfluous drag to maximize flight time. There’s also something to be said for modernity though, and prolific hacker [Tom Stanton] puts them together with this supercapacitor plane.

If that sounds familiar, it’s because [Tom] did this before back in 2023. But for that first attempt he converted a commercial R/C toy rather than a plane optimized for low-power free flight. Just like with the best rubber-band machines, his goal for the new production is more flight time than winding time. Plus lots of views on YouTube, but that goes without saying.

Thus this machine is smaller and lighter than the previous iteration. Rather than balsa and tissue like the free-flight aircraft of our youths, [Tom] is using 3D printed plastic for the structure. But he’s got a neat hack built in: he’s printing the wings and control surfaces directly onto tissue paper, eliminating the bonding step. Of course that means his wings are printed flat, but a bit of heat and some bending and he has a single-surface airfoil. Single-surface airfoils are normal in this application, anyway: closed wings add too much weight for too little gain. If you want to try the technique, he’s got files on Printables.

Another interesting factoid [Tom] discovered is that the energy density of supercapacitors decreases sharply below 10 F. As you might imagine by the square-cubed law, bigger is better, but the sharp drop-off dictated he use a single 10 F cap for this build, along with a micro motor. Using the wind-up generator from his previous build, he’s able to get 45 seconds of flight out of just 4 seconds of cranking, a good ratio indeed.

[Tom] seems to like playing with different ways to power his toys; aside from supercapacitors, we’ve also seen him finessing aircraft air motors — including an attempt at a turbine for a model helicopter.

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Fixing A GameCube’s Dodgy Optical Drive With Fresh Capacitors

April 17, 2026 by Maya Posch No comments

Generally when a game console with an optical drive stops reading discs the first thing that people do is crank on the potentiometer that controls the power to the laser diode to ramp up its output. While this can be a necessary solution to eke out a bit more life out of a clearly dying laser diode, this can actually massively shorten the lifespan of a good diode that’s just held back by bad capacitors. This is demonstrated by [Skawo] with a fix on a GameCube that stopped reading discs.

While it’s absolutely true that laser diodes have a limited lifespan, so do the capacitors and other components in the system. Thus, after tearing down this Japanese GameCube, [Skawo] accesses the optical PCB for some delicate plier-based capacitor surgery. One can absolutely question such violence, as well as the replacement mix of MLCC ceramics and a stray THT electrolytic capacitor, but the results after reassembly are obvious.

Without having to adjust the laser diode’s potentiometer, the game console now happily reads the game disc while the laser diode breathes a sigh of relief. Although all GameCube consoles will face the inevitable demise of their optical drives – barring a replacement optical pickup solution appearing – with this capacitor replacement solution it’s at least possible to stave off that undesirable time for a bit longer.

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FRED Comes To Hobby Operating Systems (and Linux)

April 17, 2026 by Julian Scheffers 3 Comments

Those who have worked on a hobby operating system for x86 will have interacted with its rather complex and confusing interrupt model. [Evalyn] shows us why and how to use Flexible Return and Event Delivery (FRED), a new standard by the x86 Ecosystem Advisory Group.

Of course, it would be silly to omit the fact that Linux received patches first. But that isn’t the interesting part; after all, Linux is often the first place to have support for this kind of thing. No, what’s interesting is [Evalyn]’s implementation, to our knowledge among — if not the first — non-Linux operating system to support it.

Part of the startup log of EvalynOS — The kernel confirming that FRED has been detected and enabled

To know why we should switch to FRED, we must first understand what it replaces. The Interrupt Descriptor Table (IDT) tells the CPU what code to run when certain interrupts or faults happen. The big problem that the IDT has is inconsistency, most egregiously the fact that the stack layout depends on which interrupt happened. To solve the issues with the IDT, FRED was created.

[Evalyn] shows us the process, starting at the documentation, then finding an emulator capable of it and culminating in a demo where DOOM runs in EvalynOS with FRED enabled.

Pentium II die shot. Martijn Boer, Public domain.

Making A Bronze Mirror From Scratch

April 17, 2026 by Maya Posch 15 Comments

Although modern-day silvered glass mirrors have pretty much destroyed the market for bronze mirrors, these highly polished pieces of metal once were the pinnacle of mirror technology. Due to the laborious process required these mirrors saw use essentially only by the affluent. That said, how hard would it be to make a bronze mirror today with all of the modern technologies that even a hobbyist can acquire for their shed? Cue [Lundgren Bronze Studios] giving it a shot, starting by casting something flat-ish to start polishing.

Just getting that initial shape to start polishing is a chore, with hammering out the shape possibly being also a viable method. When casting metal it’s tricky to avoid having air bubbles and other defects forming, though using a sand mold seems to help a lot.

After you have the rough shape, polishing using power tools seems like cheating, but as you can see in the video even going from 50 to 8000 grit with a rotating disc left countless scratches. Amusingly, hand sanding did a much better job of removing the worst scratches, following which a polishing compound helped to bring out that literal mirror finish.

A quick glance at the Wikipedia entry for bronze mirrors shows that a tin-bronze alloy like speculum metal was used for thousands of years as it was much easier to polish to a good mirror finish. The metallurgy of what may seem like just a vanity item clearly goes deeper than just polishing up a metal surface.

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Cooking With Plasma (Not Fire)

April 17, 2026 by Dave Rowntree 8 Comments

Cooking food with fire is arguably the technology that propelled humans to become the dominant species on Earth. It’s pretty straightforward to achieve, just requiring a fuel source, a supply of oxygen from the air, and a way to initiate the reaction; then it self-sustains. You wouldn’t think there’s much to improve, but what about cooking with plasma? [Jay] from the plasma channel is no stranger here, and he thinks that there may be something in this idea, certainly enough to actually build something.

Now, let’s be straight with you, this isn’t a new concept, and you can buy a plasma-based cooking appliance right now. But they are all AC-powered devices. What if you want to go camping? [Jay] attempts (and succeeds) in building a portable, rechargeable 600W plasma cooking device that can actually cook food, but it was not all plain sailing.

The existing off-the-shelf ZVS driver modules available were a bit weak and unreliable, and the required flyback coils were hard to find with the right specs, so he needed to get down to work building custom parts. First off, the coils. Custom formers were resin-printed and machine-wound with 4000 turns of fine wire, and then resin-sealed into the former. [Jay] takes care to explain that it is crucial to get all the air out of the windings, or else local flashover breakdown will occur and wreck the coil in a short time. We reckon the resulting coils look amazing in their own right!

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2026 Green Powered Challenge: SolMate Charges On The Move

April 17, 2026 by Matt Varian 4 Comments

We’ve all had those times when your electrical device of choice is running low on battery. Sometimes you even plan ahead and are also carrying a battery pack, but what happens when you’ve forgotten to charge the battery pack? This is the problem that [Arnov Sharma] addressed with the SolMate, a portable solar panel that keeps a battery bank topped up.

The SolMate is built around an efficient 2 W photovoltaic panel that’s not much bigger than a cellphone. This panel can supply 5 V at 400 mA on a sunny day. The solar output is more than enough to keep the internal 2000 mAh battery topped up and ready for use. Charging the Li-ion battery is handled by an IP5306 power management chip, which pulls double duty: it safely regulates charging while boosting the battery’s 3.7 V to the 5 V expected at the USB charge ports. Speaking of charge ports, the SolMate includes both a USB-A and a USB-C port, plus a switch to enable or disable the unit.

The case is all 3D printed, with some clever design choices. Offsetting the bulk of the battery and PCB storage area to one side lets the SolMate naturally cant toward the sun. Even the clip used to attach it to a backpack is printed.

Be sure to check out the other entries into our latest challenge!