The RepRap is a self-copying 3D printer. The project has published plans for creating a lasercut acrylic version of the device. They call it a RepStrap since once assembled it could produce printed plastic versions of the machine components, bootstrapping true RepRaps. The plans are available for Ponoko an on-demand product service, and it would cost ~$380 if you used their service. The plans are free, so you could get them manufactured by other means. [vik] is still putting together the assembly instructions. He hopes to have an all inclusive electronics kit at some point too. This is another great step towards putting desktop manufacturing within reach of everyone.
classic hacks2787 Articles
Jar Of Fireflies

[Randomskk] has been attempting to make electronic fireflies for quite some time and finally settled on a design he liked. His jar of fireflies uses an ATtiny13 to control a set of 12 matrixed LEDs. The green SMD LEDs are each soldered to a pair of thin wires that hang down into the jar. The software picks an LED at random to flash and then flashes it 1-3 times. The random seed is incremented each time the jar is turned on, so you’ll get 255 different patterns. The power is just a standard coin cell. The project is fairly simple electrically, but the LED soldering could prove difficult. It was inspired by this firefly jar project. Check out [Alex]’s synchronizing fireflies too. A video of the jar is available below. Continue reading “Jar Of Fireflies”
LED POV Hard Drive Clock

[Ian Smith] sent us this POV display made from an old hard drive. It works by flashing some LEDs under the platter, which has a line cut in it. Since the platter spins at roughly 90 rotations per second, we perceive a solid image. He was inspired by [Alan Parekh]’s project, but did several things differently. Mounting the LEDs was much simpler in this project as he had a strip of RGB LEDs that came with adhesive tape on the back. He also used a small magnet and a hall effect sensor to measure full rotations instead of an IR beam sensor. Check the video after the break.
Internal Wireless Mouse On A Dell Mini 9

[strider_mt2k] sent in this new Dell Mini 9 hack. After seeing the recent GPS in a Dell Mini9 project, he decided to jump in and do some hacking of his own. His idea was to integrate his Logitech wireless mouse receiver internally. He basically added an internal usb port, allowing for future replacements if the mouse should it get broken or upgraded. The final result is completely hidden. There was plenty of space in the case, so there’s no bulge at all.
Cambridge Autonomous Underwater Vehicle

The Cambridge Autonomous Underwater Vehicle, built for the SAUC-E Challenge, is a fantastic example of UAV construction. The competition is to build a UAV that can complete an underwater assault course. This baby has a full computer inside it, based off of the worlds smallest full featured x86 motherboard, the Pico-Itx. It has a 1GHz EPIA PX 1000 Board, 1 GB of RAM, Wireless Network capabilities and runs Ubuntu server 8.04.
The CUAV suffered from leaks which ultimately cost it the competition, but the information on the build is fantastic. They have detailed pages upon pages of information about the Mechanical, Electronic, and Software aspects of the design. They even went back in and added notes from what they learned during the competition. The project is also outlined in much shorter form on the mini-itx website.
[thanks Vesaines]
How-to: Make An E-paper Clock From Esquire Magazine

If you’ve never heard about electronic paper, crawl out from under that rock and read up on the Sony Reader and the Amazon Kindle. E-paper is a flexible display made of color-changing beads that mimic ink-on-paper for easy daylight reading. The revolutionary thing about e-paper is that after it’s set, it stays that way without additional power.
This sounds great in theory, but Esquire’s cover is the first time everybody can afford to hack an e-paper display. We took the cover into the Hack a Day lab to document, test, and hack. In the end, we recycled it into something useful that anyone can build. We’ve got all the details on how the display works and what it takes to use it in your own projects. Read about our e-paper clock hack below. Continue reading “How-to: Make An E-paper Clock From Esquire Magazine”
FM Stereo Transmitter

Reader [Mike Y] responded to our “What are you working on?” post with his stereo FM transmitter project. If you’ve ever used an FM transmitter for your portable audio, you know that even the best consumer level ones can be difficult to make sound decent.
He obtained an NS73M FM Transmitter module from Niigata Seimitsu Company, but it required a controller to handle pre-emphasis, modulation level, frequency, and power level. He decided on an Arduino which would also control his LCD.
His results were quite good, with decent range and superb audio quality. His total cost thus far is $35, but he still needs to put it in an enclosure. You can find complete schematics as well as source code and helpful tips on his site. You may also want to check out the regulations on broadcasting(pdf) as well.
