An Even More Useless Machine

December 22, 2012 by Brian Benchoff 56 Comments

Here’s the most useless machine we’ve seen so far. It comes from the workshop of [forn4x] and happily turns itself off whenever any one of its eight switches are flicked to the on position.

The build began when [forn]’s Canon 850i printer gave up the ghost because of a broken print head. All the other electronics and mechanics were still salvageable, so it was decided to turn this printer into something a little more useless.

The printer used a regular DC motor with an optical encoder to move the print head. [forn] easily found the schematics for this optical sensor, because of the TTL output was able to read out the position of the slider. The rest of the build is an ATMega8, a servo, and an octet of toggle switches. [forn] has been able to get the accuracy of the servo-controlled arm down to about 0.1 mm, more than enough to accurately turn all its switches off.

You can see [forn]’s most useless machine in action after the break.

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FireHero: Raspberry Pi Controlled Pyrotechnics

December 22, 2012 by Eric Evenchick 24 Comments

To put on a live pyrotechnic show at a music festival, [Chris] built the FireHero 3. The result is remotely controlled flames shooting up to 100 feet in the air.

The system is controlled by a Raspberry Pi and an Arduino. A server runs on the Pi and allows a remote computer to control the system. The Pi sends commands over serial to the Arduino, which switches solid state relays that actuate the valves.

There’s also some built in safety features: the system won’t boot unless you have the right key and RFID tag, and there are pressure transducers and temperature sensors to ensure the system is operating safely. A CO2 actuated valve can quickly stop fuel flow in an emergency.

Vaporized propane creates the fireballs. The vapor is created by heating the supply tank in a hot water bath. An accumulation tank stores the vapor and custom built manifolds distribute it to the various flame cannons. At each cannon, a silicon nitride hot surface igniter (HSI) is used to ignite the flames once the valve is opened.

After the break, watch a video the the FireHero making some flames.

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Watermelon Air Boat

December 17, 2012 by Mike Szczys 35 Comments

We think you’ll turn a few heads in Central Park if you’re driving a water melon around when everyone else is piloting sailboats. This watermelon is both sea worthy and radio controlled thanks to the work which [Starting Electronics] put into it.

We used this image because it shows you what’s inside of the hull, but you don’t want to miss the thing motoring around an above-ground swimming pool in the clip after the break. The hollowed out shell is quite buoyant and has no problem staying afloat and upright with the addition of a propeller. The parts from a remote control airplane kit have been mounted on a wooden scaffold. This provides plenty of thrust with a servo motor moving turning the prop for directional control. There is no dagger board so the craft is a bit slow to respond to turns. But how responsive do you expect a floating melon to be?

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[Staci Elaan]’s Awesome Portable Tesla Coils.

December 8, 2012 by Caleb Kraft 45 Comments

We stumbled onto [Staci’s] videos a while ago when we posted this big tesla gun. While it wasn’t the first portable coil we had seen, it was certainly an impressive implementation. In the comments we found [Staci] had already been making these for a while. Hers were big and small, had awesome modulation, and looked freaking cool too.

It also should be pointed out that [Staci] donates her coils to people when she’s done! Let me say that again, she gives them away to groups of people that could use them. That deserves some respect.

Unfortunately, [Staci] didn’t document her builds in great detail at the time. She has added some information recently though. You can read about her first working prototype from 2006, or a slightly more modern one here.

Of course, the real fun is in seeing them work.

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Pixar-style Lamp Project Is A Huge Animatronics Win

December 2, 2012 by Mike Szczys 39 Comments

pixar-lamp-animated-procedurally

Even with the added hardware that lamp still looks relatively normal. But its behavior is more than remarkable. The lamp interacts with people in an incredibly lifelike way. This is of course inspired by the lamp from Pixar’s Luxo Jr. short film. But there’s a little bit of most useless machine added just for fun. If you try to shut it off the lamp shade is used to flip that switch on the base back on.

[Shanshan Zhou], [Adam Ben-Dror], and [Joss Doggett] developed the little robot as a class project at the Victoria University of Wellington. It uses six servo motors driven by an Arduino to give the inanimate object the ability to move as if it’s alive. There is no light in the lamp as the bulb has been replaced by a webcam. The image is monitored using OpenCV to include face tracking as one of the behaviors. All of the animations are procedural, making use of Processing to convey movement instructions to the Arduino board.

Do not miss seeing the video embedded after the break.

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RC Truck Has Working Windows, Steering Wheel, And Much More

November 27, 2012 by Mike Szczys 23 Comments

This truck is not simply a drive train and a radio module. Great care was taken to fabricate every part to work like a full-sized vehicle. NSFW WARNING: The forum on which the details have been posted is Russian and may have sidebar ads you don’t want on your screen at work. That being said, here’s the link (translated).

The build starts with a custom-made frame which looks like it’s aluminum. The gearbox is assembled from a huge number of parts, with power is transferred to the wheels through a proper differential. But hey, why not go that extra mile? The rope and hook hanging off the front are connected to a functional winch. The doors have windows that crank down, the steering wheel moves when the wheels turn, and where would this thing be without windshield wipers and headlights? Don’t miss the pair of demo videos after the break.

We remember seeing a pretty neat stirling engine come out of the same forums earlier this year.

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USB Keyboard Becomes An AVR Programmer

November 26, 2012 by Eric Evenchick 21 Comments

[Steve] created an AVR programmer using an old USB keyboard. We feature a bunch of AVR programmers, but this one is made from parts that many people will have lying around. There are two components: the controller PCB from a USB keyboard, and an optocoupler for emulating key presses.

In order to send data to the AVR, [Steve] used the LED outputs on the keyboard. These LEDs can easily be toggled according to the HID device specification. They provide a 5 volt output with current limiting resistors, which means they can be connected directly to the target AVR.

Reading data is a bit more complex. The optocoupler tricks the keyboard into believing that a single key has been pressed, firing off a data transfer. The MISO pin on the AVR is connected to the row and column of the shift key, which is read by the driver.

On the software side [Steve] created an avrdude interface driver. This allows the programmer to be used with avrdude, just like any other programmer. [Steve] does point out that it isn’t the fastest programmer since the keyboard tries to debounce the MISO input, greatly limiting the speed. However, since it’s made from stuff you might have in your junk bin, it’s a neat hack.