Saul pointed me towards this great deal on a laser cutter. I sat there and almost clicked bid, but it’s a little outside my budget for now – if you want to laser etch Powerbooks or iPods, or cut shapes from CAD/Sketchup – this is the machine that’ll do that for you. The usual caveat: it’s an eBay sale and it’s something pretty expensive… Link.
We’ve had a few emails and posts about folks who wanted to build their own lie detector, here’s one (and how it works) – “The circuit diagram of the Lie Detector is shown above. It consists of three transistors (TR1 to TR3), a capacitor (C1), two lights or LEDs (L1 & L2), five resistors (R1 to R5), and a variable resistor (VR1). Suitable transistors to use are BC547, BC548 or BC549, or any other small NPN transistor. The Lie Detector circuit works based on the fact that a person’s skin resistance changes when they sweat (sweating because they’re lying). Dry skin has a resistance of about 1 million ohms, whereas the resistance of moist skin is reduced by a factor of ten or more.” Link.
Not bad for $44 – lots of project to make with this – “We have found many different uses for this little kit! Applications ranging from the traditional ECG/EKG monitor to the ‘Newly-Wed’ Love Synchronizer! One of the main reasons we designed the ECG1 was to answer a long running debate here at the shop. We wired up the ‘Boss’ and finally confirmed he does not have a heart! Use the ECG1 to astound your physician with your knowledge of ECG/EKG systems. Enjoy learning about the inner workings of the heart while at the same time covering the stage-by-stage electronic circuit theory used in the kit to monitor it.” Link.
Mr Joshua writes “Here’s a video Tutorial from PYRO1234321 on how to make home made lock picks.” This is a great in-depth guide running 25 minutes. Also check out other lock-picking related videos submitted by woofcat (lock picks, competitions and pick guns).” Wow, these videos are pretty comprehensive, the beginning sections on the tools and (cheap) materials are really interesting. [via] Link.
Not a bad deal for $49. “MIDISpeak Module – Version 2, The Talking Toy MIDI RetrofitAdds a standard MIDI IN port to your Speak & Spell, Speak & Read, or Speak & Math. Non-English versions also supported. Trigger thousands of sounds–words, word fragments, garbled speech, percussion and bizarre sound effects.” Link. In MAKE 04 we also show you how to build music toys like this. Modify a Casio keyboard (or other electronic audio stuff) and start playing some of the strangest sounds you’ve ever heard.
William on GoRobotics writes “The popular educational and hobbiest company, Parallax is finally offering kits with USB support! The long-standing support of serial control in robotics and microcontrollers continues to be a problem, so it’s good to see some of the larger players begin to make the change.” Link.
Matt writes “This stuff looks pretty incredible. To me the finished product looks a bit like an adobe building. It should greatly increase affordable housing in areas where it would have previously been too expensive.” Grancrete is a spray-on structural cement and here’s an overview of the Grancrete rapid construction process…” Link. Anyone ever use/see this in action?
