CNC Table Saw Jig

table saw jig

[Woodgears.ca] seems to be a wealth of clever hacks, and this CNC box joint jig is no exception.  Although one has to manually move the jig to make the actual cut, it still gives the user a lot of extra functionality. One only has to click the mouse button to advance the workpiece.  One drawback to using a table saw, even with this jig is that some internal parts still may have to be cut. Check out the video after the break to see this device in action, or skip to around 3:08 to see what hand operations still have to be done.

Besides just being a cool build, we loved the box-jointed project enclosure for the electronics. As this was made in 2003, it’s nice to see that the idea of “self-replication” (at least in part) didn’t start with the [Rep-Rap]. The 10 year old (as of 2003) Thinkpad notebook computer running QBasic in DOS is a nice “hacker” touch as is using 100 Watt light bulbs as power resistors. Pretty clever electronics, especially for someone that’s known more for his excellent woodworking skills than his obvious electrical engineering knowledge! Continue reading “CNC Table Saw Jig”

Start Thinking 4th Dimensionally With A Time Circuit Tutorial

When [Phil Burgess] showed off a few I2C – controlled seven-segment displays on adafruit’s weekly vlog, the comments immediately turned to the time circuits featured in everyone’s second-favorite time machine, the Back to the Future DeLorean. The time circuits are now active, so now you can easily add a temporal display to your car well before a hover conversion.

[Phil] used these LED displays, conveniently controlled by a four-wire I2C bus. Although the displays are addressable independently, it’s only possible to assign each display to one of 8 I2C addresses. [Phil] figured out a neat way to control the 9 displays of the time circuit with the help of a 74HC138 3-to-8 line decoder.

The case was constructed out of clear acrylic lasercut in adafruit’s shop and spray painted with faux-metal paint. After installing the seven-segment displays, a Teensy, ChronoDot, and a few AA batteries finished up the build.

With any luck, the design files for the laser cut case should be available shortly, so get those I2C displays while they’re still in stock.

Dueling Mechanical Bulls

Do you have what it takes to stay on the mechanical bull longer than the next guy? Who cares! We want to know if you’ve got what it takes to build your own dueling mechanical bulls. After seeing the development stages in the video after the break we think you’ll agree that the construction part of the project is way more fun than the ‘sport’ that results. But still, we can’t watch the competition without beaming with delight too.

The project was developed by the Madagascar Institute, an Art Collective out of Brooklyn, New York. The scene displayed above is the installation at this year’s Google IO conference, where two contestants could battle it out on the same hardware, being driven the same way, at the same time. You can make out a sign on the wall in the background. It acts as the scoreboard with two red arrows, one of which will light up to identify the loser when they have been thrown from the bull.

If only this had been driven with a Bullduino… maybe next year.

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Automated System Hopes To Make Manual Road Patching A Thing Of The Past

automated-road-repair

You don’t necessarily have to live in a cold climate to experience how roads start to deteriorate once cracks begin forming in the asphalt surface. Even more frustrating than the potholes, dips, and road erosion is the snarled traffic that results from closing lanes to repair them. Researchers at the Georgia Tech Research Institute have developed a way to detect and quickly fix these cracks with minimal human interaction, making the process a bit less painful than before.

The automatic road patcher resides on a trailer which is towed behind a service vehicle at 5 km/h. Cameras mounted near the front of the device detect cracks down to 3mm in width using an array of LED lights to guide the way. Once a fault has been detected, nozzles mounted under the trailer blast the road with liquid tar to seal the crack before it becomes a real problem.

The system seems to work reasonably well in the tests we’ve seen, and researchers are tweaking the processing software to make the rig even more effective before rolling it out on a wider scale.

[via Gizmodo]

Decoding RF Link Using A PC Soundcard

[Ray] wanted to use a microcontroller to send signals to some wireless power outlets. Instead of tapping into the buttons on the remote control he is using an RF board to mimic the signals. There are two hurdles to overcome with this method. The first is to make sure your RF module operates on the proper frequency. The second is to get your hands on the codes that are being sent from the remote control unit.

Now you could just hook your oscilloscope up to the transmitter and take a look at the timing of the signals. But most hobbyists don’t have that kind of high-end test equipment in their basement or garage shops. [Ray’s] approach uses something we all have available to us: a sound card and some open source software. He connected the data pin from his RF receiver to an audio plug and inserted it in the line-in jack of his computer. Using Audacity he recorded the signal as he pressed buttons on the transmitter.  This method not only captures the data, but the time stamps native to the audio editing program let him easily work out the timing for each signal.

It’s kind of amazing what you can do with this audio analyation technique. Earlier this year we saw it used to measure response time for DSLR cameras.

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Lightsaber Lets You Pick Just About Any ‘blade’ Color

If you’re staging some epic Star Wars battles you could go original with Red or Blue lightsabers. But what if you decide you’re more of a fan of Jedi and want to go green? Or perhaps the prequels have inspired you to take on purple? Why choose at build time when you can adjust the color to match your mood.

[Phik] built himself a color-selectable lightsaber using RGB LEDs. He sourced a 5M strip of them from eBay for around $20. The pixels are not individually addressable, but each color channel can be driven with a pulse-width modulation signal to mix and match the final color. Now he could have gone with a microcontroller solution, but [Phik] decided to give himself a bit more of a challenge. He built three PWM circuits based on a 555 timer which can be adjusted with a potentiometer. It’s not going to kill any insects, but the keep-it-simple-stupid aspect of the project makes it something we could actually build ourselves. The same cannot be said for most of the replica builds we see.

Timer-based Cooling Helps Your Network Survive The Summer

Start your week off with a smile thanks to the video [Sammy] put together. It shows off the cooling rack he made for his network equipment. The project was developed out of necessity as the summer weather was causing his modem and router to heat up and at some point one of them would just shutdown and refuse to work again for hours. We haven’t run into this ourselves but it’s good to know that over-temperature safeguards have been built into the equipment.

His solution was to build a rack that offers fan cooling above and below the two pieces of equipment. As with most of his projects, we think making the video (embedded after the break) was half the fun. In addition to playing around with a turntable for some extra special camera effects he gives us a good view of the overall build. The base includes spacers and velcro strips to hold the equipment in place above a pair of exhaust fans. The standoffs at each corner of the rack suspend a second pair of fans above the equipment. But it wouldn’t look nearly as good without some custom LED effects thrown into the mix.

This is purely timer-drive. It’s a plug-in module that uses mechanical timing to switch mains. But some creative circuitry (or a small microcontroller) could implement temperature-based switching instead.

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