Kentucky-Fried Induction Furnace

[John] and [Matthew] built an induction-heater based furnace and used it to make tasty molten aluminum cupcakes in the kitchen. Why induction heating? Because it’s energy efficient and doesn’t make smoke like a fuel-based furnace. Why melt aluminum in the kitchen? We’re guessing they did it just because they could. And of course a video, below the break, documents their first pour.

Now don’t be mislead by the partly low-tech approach being taken here. Despite being cast in a large KFC bucket, the mini-foundry is well put together, and the writeup of exactly how it was built is appreciated. The DIY induction heater is also serious business, and it’s being monitored for temperature and airflow across the case’s heatsinks. This is a darn good thing, because the combination of high voltage and high heat demands a bit of respect.

Anyway, we spent quite a while digging through [John]’s website. There’s a lot of good information to be had if you’re interested in induction heaters. Nonetheless, we’ll be doing our metal casting in the back yard.

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Illumination Captured in a Vacuum Jar

Experimentation with the unusual nature of things in the world is awesome… especially when the result is smokey glowing plasma. For this relatively simple project, [Peter Zotov] uses the purchase of his new vacuum pump as an excuse to build a mini vacuum chamber and demonstrate the effect his mosfet-based Gouriet-Clapp capacitive three-point oscillator has on it.

In this case, the illumination is caused due to the high-frequency electromagnetic field produced by the Gouriet-Clapp oscillator. [Peter] outlines a build for one of these, consisting of two different wound coils made from coated wire, some capacitors, a mosfet, potentiometer, and heat sink. When the oscillator is placed next to a gas discharge tube, it causes the space to emit light proportionate to the pressure conditions inside.

exploded

For his air tight and nearly air free enclosure, [Peter] uses a small glass jar with a latex glove as the fitting between it and a custom cut acrylic flange. With everything sandwiched snugly together, the vacuum hose inserted through the center of the flange should do its job in removing the air to less than 100 Pa. At this point, when the jar is placed next to the oscillator, it will work its physical magic…

[Peter] has his list of materials and schematics used for this project on his blog if you’re interested in taking a look at them yourself. Admittedly, it’d be helpful to hear a physicist chime in to explain with a bit more clarity how this trick is taking place and whether or not there are any risks involved. In any case, it’s quite the interesting experiment.

Augmented Reality Pinball

Pinball machines are fascinating pieces of mechanical and electrical engineering, and now [Yair Moshe] and his students at the Israel Institute of Technology has taken the classic game one step further.  Using computer vision and a projector, this group of engineers has created an augmented reality pinball game that takes pinball to a whole new level.

Once the laptop, webcam, and projector are set up, a course is drawn on a whiteboard which the computer “sees” to determine the rules of the game. Any course you can imagine can be drawn on the whiteboard too, with an interesting set of rules that no regular pinball game could take advantage of. Most notably, the ball can change size when it hits certain types of objects, which makes for a very interesting and unconventional style of play.

The player uses their hands to control the flippers as well, but not with buttons. The computer watches the position of the player’s hands and flips the flippers when it sees a hand in the right position. [Yair] and his students recently showed this project off at DLD Tel Aviv and even got [Shimon Perez], former President of Israel, to play some pinball at the conference!

Chicken-powered Pendulum

Every once in a while we get sent a link that’s so cute that we just have to post it. For instance: this video from [Ludic Science]. It’s a wind-up chicken toy that kicks a pendulum back and forth. No more, no less.

But before you start screaming “NOT A HACK!” in the comments below, think for a second about what’s going on here. The bird has a spring inside, and a toothed wheel that is jammed and released by the movement of the bird’s foot (an escapement mechanism). This makes the whole apparatus very similar to a real pendulum clock.

Heck, the chick toy itself is pretty cool. It’s nose-heavy, so that under normal conditions it would tip forward. But when it’s wound up, tipping forward triggers the escapement and makes it hop, tipping it backward in the process and resetting the trigger. The top-heavy chicken is an inverted pendulum!

And have a look, if you will indulge, at the very nice low-tech way he creates the pivot: a bent piece of wire, run through a short aluminum tube, held in place by a couple of beads. Surely other pivots are lower-friction, but the advantage of using a rod and sleeve like this is that the pendulum motion is constrained to a plane so that it never misses the chicken’s feet.

Our only regret is that he misses (by that much) the obvious reference to a “naked chick” at the end of the video.

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A 4-bit Computer From Discrete Transistors

Anyone reading this uses computers, and a few very cool people have built their own computer out of chips, [zaphod] is doing something even cooler over on hackaday.io: he’s building a computer from discrete transistors.

Building a computer from individual components without chips isn’t something new – Minecraft players who aren’t into cheaty command blocks do it all the time, and there have been a few real-life builds that have rocked our socks. [zaphod] is following in this hallowed tradition by building a four-bit computer, complete with CPU, RAM, and ROM from transistors, diodes, resistors, wire, and a lot of solder.

The ROM for the computer is just a bunch of 16 DIP switches and 128 diodes, giving this computer 128 bits of storage. the RAM for this project is a bit of a hack – it’s an Arduino, but that’s only because [zaphod] doesn’t want to solder 640 transistors just yet. This setup does have its advantages, though: the entire contents of memory can be dumped to a computer through a serial monitor. The ALU is a 4-bit ripple-carry adder/subtractor, with plans for a comparison unit that will be responsible for JMP.

The project hasn’t been without its problems – the first design of the demux for the ROM access logic resulted in a jungle of wires, gates, and connections that [zaphod] couldn’t get a usable signal out of because of the limited gate fan-out of his gates. After looking at the problem, [zaphod] decided to look at how real demuxes were constructed, and eventually hit upon the correct way of doing things – inverters and ANDs.

It’s a beautiful project, and something that [zaphod] has been working for months on. He’s getting close to complete, if you don’t count soldering up the RAM, and already has a crude Larson scanner worked out.

Open-Source Laser Shooting Simulator

Looking to practice your marksmanship skills at home? Check out the homeLESS (Home LasEr Shooting Simulator), an open-source tool for marksmanship practice. [Laabicz] developed this system as a cheaper alternative to commercial laser shooting simulators, which are just as simple but very expensive.

[Laabicz]’s simulator primarily uses modified airsoft pistols that are fitted with batteries (installed in the magazine) and a laser in the chamber. Any gun can be used with the system as long as you can figure out how to attach a laser and trigger switch. To power the laser, a small capacitor is charged from batteries when the trigger switch is off. Once the trigger is pressed, the capacitor discharges through the laser and makes a short pulse of light.

The simulator is written in Processing and requires a projector and a webcam. The Processing sketch projects configurable moving targets on a screen or wall, and the webcam detects when a laser is triggered over any of the targets. The software supports multiple target types (including moving targets) and is quite configurable. Check out the video after the break to see the system in use.

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Video Spiel Kultur

Somehow, and don’t ask us how, the venue we chose for the Hackaday Prize party was perfect for Hackaday-related shenanigans. There was a Hackerspace right around the corner, a computer history museum in a warehouse nearby, and an amazing video game archive barely 100 meters away from our venue.

The VideoGamingArchive is an amazing collection of video games from the era where video games came in boxes with real manuals, and you needed to be sure you bought the game compatible with your system. Inside, one wall is dedicated to the old cardboard computer boxes, indexed partly by system and partly by how cool they look, while the other wall was dedicated to games from the previous five generations of consoles.

[Nils] was kind enough to give me a tour. You can check that video out below, with some more pics below that. If you’re wondering, yes, that is a sealed copy of Chrono Trigger, and no, I have no idea what it’s worth.

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