Printing A RepRap

July 22, 2009 by Zach Banks 61 Comments

repstrap

The RepRap project has been working on bringing 3D printing to the masses by creating a extrusion printer that can also make the majority of its own parts. For the most part, these print ABS or HDPE plastics which are strong and recyclable. In order to create these replicating printers, similar machines called RepStraps are built out of either laser-cut parts or machined elements. They are functionally equivalent to RepRap printers, but are not made of printed parts. [nophead] documented his RepStrap, HydraRaptor, that is based off a milling machine. He had already printed a set of RepRap parts, and he documented printing a second set. The machine worked for about 100 hours over the course of 2 weeks, printing about 1.5 kg of parts. He made a few adjustments, such as replacing ABS bearings with HDPE to reduce friction. The parts are for Factor e Farm so they can get started with 3D printing.

Related: RepRap pinch wheel extruder

AR Flash Library Released

July 21, 2009 by Zach Banks 11 Comments

[youtube http://www.youtube.com/watch?v=CMpJLTU9qCA%5D

[onezerothrice] has been working hard on creating ARtisan, a flash library for bringing augmented reality to the browser. His goal in creating the library was to make AR projects quicker and easier to develop. The library can provide the location, size, and rotation of multiple markers on screen with little work from the developer. It is licensed under the GPL and comes bundled with Papervision3D, another flash library for manipulating objects in 3 dimensions. He has posted several demos with source and accompanying video.

Gimbal Camera Stabilizer

July 15, 2009 by Zach Banks 38 Comments

steadycam

Professional cameramen use steadicams to make their shots look smooth and clean. However, their prices are generally way too high for an indie’s budget. Previous attempts have tried adding a counterweight and moving the camera away from the hands. [YB2Normal] took a different method and used a bob and gimbal to hold the camera upright. The gimbal is free to rotate along 3 axes, so the camera can stay in place. The whole thing cost less than $15. The first video he made with he mount is after the break.

[youtube http://www.youtube.com/watch?v=nXB0ncUQLn4%5D

Related: Building a Snorricam

[via Gizmodo]

Binary Reversing Comic

July 14, 2009 by Zach Banks 26 Comments

b300

Last month, in preparation for Defcon 17, the qualifiers were held for capture the flag, one of Defcon’s most well known events. One participant, [mongii], did a writeup on how to solve problem B300. The challenge was to find the decryption key used by a program that had several twists that hindered debugging. After grappling with self-modifying code and junk instructions, the team was finally able to find the answer. This win helped Sapheads place in the top 10. Over at xchng.info, they are collecting solutions to the other problems. Sadly, they’re not all in comic form.

Etch PCBs With Ferric Chloride And A Sponge

July 13, 2009 by Zach Banks 29 Comments

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Etching a printed circuit board generally takes a bit of time and uses a lot of etchant. [TechShopJim] posted a method that uses a sponge to reduce the amount of etchant used while speeding up the entire process. First, a resist is applied using either a sharpie or the toner transfer method. Using gloves to handle everything, he soaked a sponge in ferric chloride and continually wiped a copper-clad board until all the exposed copper was removed. This technique moves the etchant around more, keeping “fresh” etchant closer to the copper. If you can’t procure ferric chloride, you can also use our method that uses 2 household chemicals: hydrogen peroxide and hydrochloric acid.

Hacking An IButton

July 9, 2009 by Zach Banks 36 Comments

breadboard1

Maxim’s iButtons, which are small ICs in button-sized disks, are starting to show up in more and more places. They have a range of uses, from temperature loggers to identification, and all use the 1-wire protocol to communicate. Over a furrtek, they hacked an iButton used for buying things from vending machines and created an infinite money cheat. They built a small rig based on the ATmega8 to read and write data to the chip. The data was encrypted, so it wasn’t feasible to put an arbitrary amount on the card. Instead, they used a similar technique to the Boston subway hack and restored a previous state to the iButton after something was bought. They also created a hand-held device to backup and restore the contents of a button for portable hacking.

[Thanks furrtek]

AVR Boost Converter

July 7, 2009 by Zach Banks 19 Comments

avrboost

Over at SpriteMods, [sprite_tm] realized that a microcontroller could be used as a boost converter to power itself. A boost converter steps up voltage from a battery by switching the output of a coil. First, it is tied to ground so a magnetic field can build up in the coil. It is then released as a higher voltage than the input. Normally dedicated chips do this at an incredibly high frequency, but the PWM signal from an AVR works well enough. This can be used in low-power situations where space is an issue.

[via EMSL]