Regenerative Bike Brakes

September 4, 2008 by Caleb Kraft 21 Comments

For their senior design project at Arizona State University, these guys built a regenerative braking system for their bike. As they brake, the system spools up to give them a push back up to speed. They achieved 25% efficiency on one run, which isn’t too shabby.

The site has all kinds of information. You can check out their different plans and ideas from before they decided on this specific layout as well as all their data from the test runs. Be sure to look at the piece by piece breakdown of what changes were made from the initial design.

[thanks Mario Gomes]

Interactive Globe Display

September 2, 2008 by Caleb Kraft 1 Comment

[ERASME] built this interactive globe interface for an exhibit on Inuit people and their land. The goal was to have a tactile input device to Google Earth data. The unit is composed of a half globe for location selection, a touch pad for layer selection, and a Wiimote for view changes.They had to develop their own driving application for Google Earth as none exists for Linux. The software, called KeyEvents takes inputs from all the devices and mimics keyboard and mouse control in Google Earth.

There is much more information on how they got the pieces to work together, as well as some videos in french showing the device working. One thing that stands out though is that they decided to use direct association on their Wiimote, thus stopping rogue Wiimotes from gaining control. Who would carry a Wiimote around just to hijack public displays? We would.

[thanks Leucos]

RGB Desktop Clock

September 1, 2008 by Eliot 11 Comments

[youtube=http://www.youtube.com/watch?v=-hxZRCponks&hl=en&fs=1&rel=0][Mark Roy] designed this fine RGB LED desktop clock. It uses a PIC16F877A microcontroller and a DS1307N Real Time Clock. There is a ring of 12 RGB LEDs around the perimeter. Hours are indicated in red, minutes green, and seconds blue. If the hands overlap, the colors are mixed. Three buttons are used to set the time and it can run on as little as 0.7volts. You can find out more about the project on Stellar Core. He has plans to kit it in the future.

Apollo Guidance Computer Clone

August 31, 2008 by Eliot 9 Comments

[Cliff Miller] pointed out this incredible project from 2004. [John Pultorak]’s journey began in late 2000 when he decided to build a 60’s or 70’s era minicomputer. While gathering technical documentation, he found some interesting information on the Apollo Guidance Computer and felt that was the way to go. The AGC was the first integrated circuit computer ever built. Designed by MIT in 1964 it was constructed from ~5000 ICs, almost all 3-input NOR gates. [John]’s version uses late 1960’s 74LS TTL logic which gains him a 10 to 1 reduction in the number of ICs. A good thing when you have to do ~15K wirewrap connections. He also used flipflops and register chips instead of building everything from NOR gates. [John] essentially built the AGC three times: First, he coded a simulator in C++. Then, he imported the logic design into CircuitMaker to verify that it would actually work. Finally, he built the 3 by 5foot machine. He’s provided an amazing amount of documentation for anyone that wants to explore this device and the overview alone is well worth a look.

Hacking A Scale To Test Rocket Motors

August 29, 2008 by Caleb Kraft 7 Comments

[David Steeman] sent us this project. He uses a consumer scale to measure rocket engine thrust. He wanted to be able to map the thrust curve of his homemade rocket motors to determine whether they are meeting the design goals. It does this by measuring the force applied by the rocket engine via a microcontroller that records it in a text file on a computer. He then analyzes this data in an Excel spreadsheet.

The sensors were harvested from a consumer scale while the rest of the electronics were built by hand. He’s using a PIC 18F2550 microcontroller which has a built in USB interface. He has breakdowns of each piece with detailed information on how it works as well as some nice pictures. There is also a list of future improvements that he would like to do such as increasing sample speed, integrating it with the ignition, and decreasing the physical size. Files for the schematic, firmware, and excel spreadsheet are available for download at the bottom of the page, so keep scrolling down.

1100 Barrel Paintball Gun

August 29, 2008 by Eliot 33 Comments

[Adam] and [Jamie] from Mythbusters built a paintball gun with 1100 barrels as some graphics card marketing gimmick. It’s a formidable beast, but we’re sure it takes forever to prep.

[via Laughing Squid]

Aurora Mixer Now Available

August 28, 2008 by Joey Celis 9 Comments

It’s been a long time coming but that highly sought after open source mixer, the aurora224 is now available for purchase on the company’s website. The aurora mixer is a fully programmable USB mixer complete with 24 back lit knobs, 2 faders, and a single crossfader.

While the instructions on how to assemble your own mixer from scratch have been available for sometime now, many wanted a kit complete with everything needed to avoid having to source the parts themselves.

The aurora mixer is available in 2 versions, a fully assembled turn key deck and a DIY kit that requires the use of a soldering iron and the ability to follow directions.

So, if you’ve wanted to build your own aurora mixer but never knew where to start, this may be your lucky day. Don’t wait too long as you have until September 1st to get your order in.