Gas Plasma Pinball Display

August 28, 2010 by 13 Comments

[Whoopjohn] decided to build a driver board for a display he pulled from a pinball machine. You’ve probably seen these used to scroll both score and messages using a total of sixteen 15-segment digits. We’d love to get our hands on one, and you might too but where? [Whoopjohn] notes that these were usually installed two-per machine and the driver boards were run close to their maximum ratings. That means that somewhere there’s a collection of broken machines with working displays. If you do plan to make this happen, you should be able to figure out the circuit based on this commented board layout (pdf).

Tube Preamp With A Dazzling Wood Case

August 28, 2010 by 8 Comments

It’s been a while since we’ve looked in on the world of vacuum tube audio equipment. [Bruce] just finished documenting a tube preamp he built. He actually made a couple of these with slightly different cases but they use the same circuit design. We found his discussion of common errors made when tying into ground quite interesting. It seems that many folks struggle with noise in their circuits because of ground loops. There’s some details about isolating the signal ground from a metal chassis, and also an admonition about not connecting the input or output jacks directly the chassis.
If you like this, don’t miss on of our favorite tube projects, [Bruce’s] Poddwatt.

Robotic Helicopter That Can Grasp A Payload

August 28, 2010 by 10 Comments

Like the Grand Theft Auto RC missions come to life, this helicopter can grasp objects for transport. They don’t have to be a special size or shape, and it can lift them even if they are not centered. This is thanks to a load-balancing hand (originally developed as a prosthesis) that relies on flexible joints and a tendon-like closing mechanism. As you can see in the video, the light-weight chopper has an on-board camera so that the operator can see what is being picked up. This little guy has no problem lifting objects that are over one kilogram while remaining stable in the air.

[Thanks Paul]

Airport Express Speaker Mashup

August 27, 2010 by 12 Comments

[Wei] salvaged the internals from an Airport Express that had a blown power supply. From there he built this streaming music box. The case is from an IKEA clock with the face removed. He added some decorative fabric around a grill to make an acoustically transparent front panel. Inside you’ll find the Airport guts connected to a USB charger (replaces the dead PSU) and a set of powered stereo speakers. This simple mashup looks good and frees up space in your junk-parts box.

Hydropower Generator

August 27, 2010 by 36 Comments

[Paul] wanted to have access to renewable energy at his cabin. It’s a relaxing place, nestled in a tall forest that shelters him from the sun and wind. This also means that solar and wind energy aren’t an option. But there is a stream running through the property so he decided to build his own version of a small water-powered generator.

He tapped into a reservoir about 200 feet upstream, split the flow into four smaller hoses, and channeled that into a five-gallon bucket. Inside the bucket you’ll find a Pelton wheel he built which turns a low-RPM generator. He manages to generate 56 VDC at 10 A with this setup, more than enough to charge a bank of batteries.

He does a great job of explaining his setup in the video after the break. If you’re looking for other ideas of how to cut down on your environmental impact check out this compost-powered water heater.

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IPhone Drum Machine Isn’t Synthesized

August 27, 2010 by 11 Comments

There was a time when a drummer would grab some sticks and lay out a groove using the items around him as instruments. [Lsa Wilson] would rather not work quite that hard and has chosen to do the same thing by tapping on an iPhone screen. As you can see in the clip after the break, many of the items in the room around him have been fitted with solenoids. Each is connected to an Arduino which is then controlled by Open Sound Control and interfaced with the iPhone via TouchOSC. We love the sounds being created and can’t help being reminded of the Multixylophoniomnibus.

Devote Your Life To Replicating A Lightsaber

August 27, 2010 by 21 Comments

Life-sized Star Wars replica props, it’s one way to keep the ladies away. But if you’re going to make them, you should do it right. [Bradley W. Lewis] spent some serious time getting this [Obi-Wan Kenobi] lightsaber right. The seven-page build log provides plenty of eye-candy. We especially enjoyed the machine and coloring of he grenade-fin portion. The LED ladder that lights the blade is also quite interesting. For the icing on the cake he incorporated a high-performance speaker connected to the sound board from a Hasbro Force FX which provides that classic swashbuckling sound from a galaxy far, far away.