Electromagnetic Harp With Home Made Ebows

Fresh from the Arduino subreddit comes [dataplex]’s 26 string electromagnetic harp. It’s a very cool, ambient instrument that sounds simply phenomenal through the Space Echo and Fender Twin rig [dataplex] has.

There’s not much in the way of build details, but judging from this post [dataplex] made several months ago the instrument works on the same principles as an Ebow. There’s a great prototype video showing the hardware and software. One small voice coil reads each string. A tiny op-amp sends this to another voice coil and back into the string. There’s tons of feedback, but it’s great for an ethereal ambiance.

The prototype is controlled by an Arduino via a computer, but for the final build [dataplex] moved on to a copper/zinc touch interface on the front of the harp.

It’s a very, very cool instrument and we’re waiting patiently for the build details to be released. You can check out the videos of [dataplex]’s work after the break.

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Music Visualization Generator With A Propeller

The folks over at Gadget Gangster have been working on a music visualization system using a Parallax Propeller. The visualizations are awesome in their early-90s demoscene way, and of course we love anything using the oft under-appreciated Propeller.

The project is called Video Beats and it generates music visualizations in the style of a blocky but very complex Atari 2600 game. There’s really not much to the build – just two RCA jacks for the audio input and video output along with a couple of resistors – but we do appreciate how nicely this project would fit in at a chiptunes show.

The Gadget Gangster team says the input isn’t limited to just audio – a potentiometer, accelerometer, or even a light sensor can be added to the build for a more dynamic output. After the break, you can see the demo of Video Beats, and a [Family Sohn] music video that used an early version of this circuit.

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Robotic Light Painting In 3D

For the last few months, [Ben] has been building a 3D light painting robot. Instead of a couple Arduino-controlled LEDs that a person moves around the Lightplot, as [Ben] calls it, uses a robotic arm to move a LED in 3D space.

The build started with [Ben] testing his idea by putting a laser pointer on an altitude and azimuth mount made out of LEGO. Eventually [Ben] decided to build a 3D plotter rig for a more impressive show. The 3D plotter sits in on a tripod with three axes of motion – up and down, clockwise and counterclockwise, and ‘in’ and ‘out’. A small RGB LED at the end of the robotic arm is controlled along with the servos and motors, making it possible to plot vector lines in 3D space.

There are a whole bunch of demo videos after the break. They look fantastic, but we’d really like to see the Lightplot be used outside on a dark, starry night.

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Hackaday Links May 9th 2012

Homecut – CNC Cutting Directory


So you have a CNC machine that you use as a hobby, but would like to do some actual work on the side? Or maybe you have an idea you’d like made. Homecut is a map directory where you can maybe hook up with the right person.

The Curta Mechanical Calculator

curta calculator

As [leehart] mentioned in our comments section, the Curta mechanical calculator is a truly ingenious piece of engineering. A quick Google search should find all kinds of information on it, but this article could be a good place to start for some mechanical hacking inspiration!

Luxman Amplifier DAC Upgrade


[R. Barrios] wasn’t happy with using the sound card for his HTPC setup, so decided to add a DAC module onto his reciever. The resulting audio quality was very good, and the build came out quite clean.  Check it out if you’re thinking of a hack-upgrade to your stereo equipment.

3D Printable Tilt-Shift Adapter


A tilt-shift lens a neat piece of equipment that is used to make a large scene look like they were miniatures. It’s a cool effect, but professional lenses to do this can cost thousands of dollars. This Instructable tells you how to go about printing your own. For more info on the technique itself, check out this Wikipedia article.

New 3D Printer on the Block


If you would like to take the plunge into 3D printing, but are looking for somewhere to get a parts kit, the [ORD Bot Hadron 3D Printer] may be worth a look.  The build quality looks great, and the price for the mechanical components is quite reasonable at $399. You’ll need to provide the electronics and extruder. Thanks [comptechgeek]!

[Phil Torrone] Interviews [Bunnie Huang] About Chumby And More

Over at Make, [Phil Torrone] has done an interview with [Bunnie Huang]. [Bunnie] has been a major contributor to the pages of Hackaday as far back as we can remember. He started in 2002 hacking X-boxes and sharing his findings with the world. It is this sharing that makes [Bunnie] stand out. He has always shared all his findings and pushed for open source wherever it would fit. We recently discussed how Chumby, a project to which [Bunnie] contributed is coming to an end. In this interview, he talks about what the future holds for himself and how he plans to spend his time. Most interestingly, he plans on spending a year just building things he’s wanted to see built. Be sure to check out the interview to see what he’s already accomplished.