“Stupid Expert” Builds A Machete Slingshot For The Impending Zombie Apocalypse

March 30, 2011 by Mike Nathan 50 Comments

Sometimes people build things for the simple challenge of building. This is one of those cases.

The gentleman you see in the image above is [Jörg Sprave] of The Slingshot Channel. He is a self-proclaimed “Supid Expert” on the subject of slingshots and has taken his love of flinging things at absurd velocities to a whole new level.

His latest creation is a machete slingshot, which is really more accurately described as a machete crossbow. Measuring over six feet long, the impressive apparatus fires a specially altered machete with an insane amount of force using thick rubber bands. In the test firing shown in the video below, the machete is embedded up to the hilt in six layers of very thick cardboard, requiring quite a bit of work to remove.

As he states in the video while brandishing his bloodied forearm, building such a device is extremely dangerous, and should be limited to “Stupid Experts” . In no way should you attempt to build one of your own.

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Jacob’s Ladder Makes Itself At Home In A Floppy Disk Box

March 30, 2011 by Mike Szczys 14 Comments

[Plasanator] adds a bit of safety to his Jacob’s Ladder by housing it in a familiar enclosure. It doesn’t take very many components to make one of these, but to get the high voltage you’ll need some type of coil. He’s using one from the electrical system of an old car, then building around it with a big 15mf 220V capacitor, a dimmer switch normally used in household wiring, terminal blocks, and some braising rod or coat hanger for the spark to traverse.

The video after the break shows this in operations, and we’d agree with [Plasanator] that this is a wonderful addition to your Halloween decor. Of course you want to keep fingers away from the dangerous bits and that’s where the enclosure and key lock come into play. Were not sure what he made the upright cylinder from, but the base is a blast from the past. Remember when one of those used to sit proudly on every desk as a tribute to how important the information you had on had really was?

Don’t want to play with high voltage like this? You can build a fake using EL wire.

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Mechanical Turing Machine Can Compute Anything…slowly

March 25, 2011 by Mike Nathan 12 Comments

mechanical_turing_machine

For several years, [Jim] has wanted to construct a fully-mechanical universal Turing machine. Without the help of any electronic circuits or electrical input, his goal was to build the machine using simple hand tools and scrap materials.

If you are not familiar with the concept of a Turing machine, they are devices that manipulate symbols or input from a strip of tape, according to a set table of rules. By definition, a Turing machine should be adaptable to simulate the logic of any computer algorithm, albeit in a much slower fashion than you would see from a computer.

He has replaced the strip of tape with a wire grid, and the symbols have been implemented in the form of ball bearings placed on the aforementioned grid. His hand-cranked machine uses magnets to lift the input symbols from the grid, processing them according to the rules table he routed out of a wood block.

The implementation is definitely clever, though [Jim] admits it is not without its problems. He took it to Maker Faire UK, and most people didn’t quite understand what they were seeing without a full explanation. The machine is not quite as reliable as he would like it to be, and he would like to make it a bit more powerful as it currently would take months to add two numbers together.

Keep reading to see a brief video demo of his Turing machine in action, and check out his blog if you want to see more information on how the machine was built.

Interested in seeing more Turing machines? Check out these two machines we featured a while back.

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Matchstick Model Rocketry

March 25, 2011 by Mike Szczys 47 Comments

[Valentin] is the MacGyver of model rocketry, building a small rocket out of three items many people have hanging around the house. Cat litter, matchsticks, and a ballpoint pen are the raw materials that he rounded up before setting to work on the build.

The housing of the ballpoint pen will act as the body of the rocket. [Valentin] stuffed the tip of the pen with cat litter, creating the first part of the fuel chamber. Next, the heads of the matches were very carefully muddled into a fine powder which fills the bulk of the pen housing. Finish this off with another plug of cat litter and you’re almost done. The final step is to drill a hole through the plug layer at the tip of the pen, creating a nozzle to focus the force as the fuel burns.

From the videos we’d say there needs to be some work done as far as rocket guidance, but the solid state fuel certainly does work. Just remember to make your personal safety the first priority when working with combustibles like this!

Wondering how to launch something like this? Here’s a way to make your own igniters.

Bubble Display

March 25, 2011 by Kevin Dady 25 Comments

As hackers we have come up with some pretty wild and unique ways to display data, but that never stops us from creating even wilder ways such as this Bubble Display. Inspired by a Hackaday article called Liquid Display the bubble display started out as a one column lexan tank so the team could check out different liquids, and build methods, which gave them the opportunity to test out their wet/dry vacuum in the basement as well.

After the leaks were solved in the prototype, different fluids were tried out to see what would work best, glycerine (though the most expensive out of the 3 items tested) gave the best performance in how the bubbles rose to the top, and the uniformity of each individual bubble.

The final tank design features (24?) channels to keep bubbles from interacting with each other and are fitted with some Parker A005-C23-2P pneumatic valves hooked up to a standard air compressor. Electrically it’s pretty standard, with the solinoid driver stuff all run by a PIC18F4455 clocked at 48MHz.

Software wise the device has 3 modes, one mode allows users to enter text or simple bitmaps from a computer using a homebrew GUI written in Visual Basic, there is also a demo loop for when you still want to show it off, but there is not someone there to constantly bang data into it, and finally a live keyboard mode which acts as a bubble music visualizer when there is a keyboard connected via MIDI. Check all 3 out in a short video after the break.

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More High Voltage Experimentation With A Flyback Inverter

March 24, 2011 by Mike Szczys 16 Comments

[Electorials] actually makes working with a flyback inverter sound rather easy. This comes hot on the heals of the huge high voltage collection we saw the other day, but slows way down in the presentation of information. This makes the project very approachable for the newbie, especially considering that the majority of the testing is done with low voltages.

He’s using a flyback transform for this project, which can be pulled from an old CRT monitor. Once you have one in hand, all that’s required to figure out how to use it is a voltometer, a 9V battery, a MOSFET (also salvaged in this case), and miscellaneous components. Once he establishes what each external connection does electronically, [Electorials] builds his circuit on a breadboard, then uses it to create plasma in the bulb above as well as to light up a CCFL.

Virtual Serial Bridge

March 24, 2011 by Kevin Dady 10 Comments

When you are running emulators or virtual machines it may be sometimes handy to be able to connect a serial port from the guest machine to the host machine. [Aurimas] had that issue, and also had a fun fix for that using 2 USB <> Serial adapters, but as you can imagine that is not a ideal solution, enter the Virtual Serial Bridge.

Digging around Vmware it was found that the support for what he needed was there, but not really used. A little addition of a few lines to the guest OS vmx file and configuring the socat multipurpose relay package. Though the instructions revolve around the Mac platform as the host and Windows as the guest socat and Vmware you can probably mix it up with any software that uses the serial port and a *x or windows host.