Hackaday Links: March 20th, 2013

Giant fresnel lens is dangerous fun

giant-fresnel-lens-is-dangerous-fun

Here’s an interesting, and rather dangerous, use for those old big screen TVs that are frequently listed for FREE on Craigslist. With the lens from the old TV built into an adjustable wooden frame, [Grant] was able to melt a stack of pennies, instantly burn wood, melt spots in concrete, and serve his family … Read the rest

Your own head-mounted display for under two bills

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[D S] wanted his own head-mounted display. What you see here is just his mockup, but somewhere along the way he realized it’s closer to a finished build than just being a stating point. Not only does it work well for gaming, it came in at under $200 all in. You think your girlfriend makes fun of you now for … Read the rest

DIY Fresnel reflector

Just like destroying an ant colony with a magnifying glass, there’s nothing like cooking hot dogs and roasting marshmallows with a nice parabolic reflector. Of course covering an old satellite dish with mylar or aluminum tape doesn’t take much skill, however cool it is. [Uwe] came up with a much more technical means of building a Fresnel reflector that will … Read the rest

Solar-powered CNC woodburning

[Johnie] built himself a CNC woodburner powered by the sun. Like the solar 3D printer we saw last summer, [Johnie]‘s build uses a giant Fresnel lens to focus sunlight onto a piece of wood. To get some control out of his build, a 2-axis bed was made from scrounged and junked parts.

The lens in [Johnie]‘s build looks to … Read the rest

Wii sensor bar projector

Having experienced quite a bit of trouble getting the Nintendo Wii remotes to work reliably with his home theater projector, [Sprite_TM] designed his own sensor bar replacement. If you’re not familiar, the Wii remotes have an infrared camera in the tip that sense two IR LEDs in the sensor bar that resides above or below your television. The problem … Read the rest

LED projector

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[PuffMag1cDrag0n] shows us how to make a fairly simple projected LED display. The projector is made from a 13×7 LED matrix and a couple fresnel lenses. The layout and construction is similar to the Lumenlab projector setup, only replacing all the lighting and LCD with an LED array. It communicates via serial port and is powered by … Read the rest