home hacks

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Tesla Turbines For Fun And Profit

October 29, 2008 by 19 Comments

[youtube=http://ca.youtube.com/watch?v=aoRh8T_VX-Y]

[Rick] has been building Tesla turbines in various ways and posting his projects to youtube. For those who are unfamiliar, a tesla turbine is a fanless turbine that uses a smooth central disk spun by friction from a gas or fluid. Since the turbine itself has no protrusions, it is extremely stable. There are lots of other benefits, which can be explored on the Wikipedia page. [Rick], as you can see from the video above has found several uses for them, from Halloween props, to generators for lights, to an automated shake flashlight shaker, you can even watch him rev one up to destruction. Though most of these are at relatively low speeds, he has shown that he can make one from CD spindles that is stable enough to reach 10,000 RPM. [Rick] admits that all they really do is spin fast and make cool noises, but they do that pretty well.

Update: Moments after this was published, we found an instructable by [Rick] on how to build a blender using a tesla turbine.

Vertical Axis Wind Turbine Update

October 24, 2008 by 14 Comments

[Faroun] sent in his updated vertical wind turbine. After running his previous one for a while, he felt that the motor he was using was inadequate, it required too high of RPM to produce what he wanted. He didn’t want to gear it up, fearing that the light construction couldn’t sustain rotation.

He built a new version that has the same surface area of fins, but much higher RPM. The new one, dubbed V8 is made mainly from PVC and an Amatek DC motor. His goal was to produce 100 watts at 35km/h. He doesn’t really state whether or not he achieved it though.

Flameless Jack-o’-lantern With An ATtiny13

October 21, 2008 by 10 Comments

[aballen] wanted to light the jack-o’-lantern this year with something that didn’t actually require fire. After searching for a project that was cheap and yielded decent results, he ended up just making his own. This project utilizes an ATtiny13 and two LEDs, red and orange.  The overall build is quick and simple with some very basic code for the flickering. If you really want it more enclosed, there is this similar project using a cheap electric candle. Of course, not everyone has the time or desire to make one that is this realistic. You could always just go the easy way, no microcontroller required.

Why limit it to just lighting up your pumpkin though? Lets take a stroll through Evil Mad Scientist Laboratories hallways and see the Snap O Lantern or the dark detecting pumpkin and the Cyclonolantern.

Keyless Entry Using Touch Sensing

October 20, 2008 by 19 Comments

[Alex] sent us this slick little keyless entry system. He wanted a discreet way to trigger the door to unlock. Knocking was too loud, and would give away his secret access code. He decided that touch sensors would be the best. Initially he planned on using the doorknob itself, which would have been awesome, but it was just too much surface area for his touch sensor. Ultimately, he settled for a wire he could touch.  An Arduino detects whether or not the correct code has been put in and initializes a high torque servo which turns the doorknob from the inside.  In the video, after the break, you can see that it works fairly well.

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Build A Solar Dehydrator

October 3, 2008 by 18 Comments

[Erik Knutzen] and [Kelly Coyne], authors of The Urban Homestead, are really into all things green and sustainable. In their blog, Homegrown Evolution, they discuss building their own solar dehydrator using plans from the February/March 1997 issue of Home Power Magazine. The dehydrator is designed by Appalachian State University’s Appropriate Technology Program. If interested, you can check out or buy other solar dehydrator designs. This seems like a great, cheap alternative to buying an expensive electric dehydrator, and you get some great advantages, like low-cost dehydrating, solar energy, and beef jerky whenever you want it. Plus, the authors point out, for most of these designs, if you remove the top box and you stick it next to a window, you’ve got a solar heater. It’s now a dual-purpose device.