Characterizing a Death Ray… er, Solar Oven

Many of you will probably at some point have looked at a satellite dish antenna and idly wondered whether it would collect useful amounts of heat if you silvered it and pointed it at the sun. Perhaps you imagine a handy source of  solar-cooked hotdogs, or maybe you’re a bit of a pyromaniac.

[Charlie Soeder] didn’t just think about it, he did it. Finding a discarded offset-focus DirecTV dish, he glued a grid of 230 inch-square mirror tiles to it and set to investigating  the concentrated solar energy at its focus. 

Cotton waste, newspaper, and scraps of fabric char and burn with ease. A cigarette is lit almost from end to end, and it burns a hole right through a piece of bamboo. Most of the energy is in the form of light, so transparent or reflective items need a little help to absorb it from something dark. He demonstrated this by caramelizing some sugar through adding a few bits of charcoal to it, once the charcoal becomes hot enough to caramelize the sugar around it the spreading dark colour causes the rest of the sugar to caramelize without further help.

Solar furnace calculations
Solar furnace calculations

To gain some idea of the power of his solar furnace, he recorded a time series of temperature readings as it heated up some water darkened with a bit of charcoal to absorb heat. The resulting graph had a flat spot as a cloud had passed over the sun, but from it he was able to calculate instantaneous power figures from just below 30W to just below 50W depending on the sun.

He records his progress in the video you’ll find below the break. Will we be the only ones casting around for a surplus dish after watching it?

Continue reading “Characterizing a Death Ray… er, Solar Oven”

3W handheld laser raises hope for a real Lightsaber someday

That banner image may seem a little bit theatric, but it’s a good representation of what this 3W handheld laser can really do. Turn the thing on in a slightly smoky room and it looks exactly like a thin beam Lightsaber.

What kind of tricks would you expect this thing to perform? Perhaps it’ll pop some black balloons? Prepare to be shocked because it’s orders of magnitude more powerful than that. The video below shows it burning and igniting a collection of items almost instantly. [Styropyro] tested his creation by igniting paper, cardboard, flash paper, flash powder, burning through a stick of wood, and igniting an undisclosed substance at the end of the video. But one of our favorites is when he drives a solar powered toy car with the intense beam.

He pulled the diode from a DLP projector, and drives it with a pair of 18650 Lithium Ion batteries which are commonly found in laptops. He made the enclosure himself. It looks great but we can’t help but wonder if the components would fit in a painstakingly made replica.

Continue reading “3W handheld laser raises hope for a real Lightsaber someday”

NES light gun gets a burning laser upgrade

The Nintendo Light Gun makes a perfect burning laser. Of course it’s been gutted to make this happen. Nonetheless, the retro look can’t be beat, and the gun form factor is just what you need in a laser weapon.

This will literally burn your eye out of your head, so [Justin] and his buddies over a North Street Labs are all wearing protective goggles designed for this laser’s wavelength. But they also built a safety into the zapper itself. At the beginning of the video clip (embedded after the break) you will see there’s a key lock mounted in the butt. This lock completes the circuit between the battery and driver board. The 2W output is achieved by a 445nm M140 diode. A lot went into the heat sink and mounting cylinder to make sure the diode doesn’t just burn up after a few seconds of use.

Continue reading “NES light gun gets a burning laser upgrade”

Hackaday links: January 24, 2011

New Project Hosting site

[Paul] wrote in to tell us about his brand new hack hosting service, HackHut. Based on WordPress with some modifications, it is definitely worth keeping an eye on as new features emerge.

Instructabliss

Speaking of project hosting, Instructables are a common source of projects as well as complaints. Instructabliss by [Daid] is an often mentioned solution in our comments, and we thought we would bring it up so commenters don’t have to. We understand why it was made and think it was a clever hack, but we don’t officially endorse it. We survive on Ad revenue, if someone were doing this to us, it would hurt. We’re also not sure about the legalities of such a service, so keep us updated.

Grass Burning Robot

[Sebastian] brings us his grass burning, flame throwing robot. This robot takes in SVG files to create its burn path, and burns away. Not too many details, but be sure to check out the photos on his site.

[via Make]

Wood burning house heater

Dabbling in alternative heating technology, [Rob Steves] built a wood stove to dispose of his scrap wood while negating his home’s fire insurance at the same time. As the leftover bits from his wood projects started to stack up he wondered how he would dispose of them. Burning the bits for heat means he’s using every last bit of the lumber. The internal tank from an electric water heater was repurposed as a combustion chamber, with exhaust gases escaping through some high-temperature flexible tubing. The glass panes were removed from one of the fireplace doors to give the off-gases a place to go. The result is a rocket stove that burns very hot and does a great job of warming his house.

It’s not the safest way to heat a home, and there may be coding issues with your municipality. But this might go well in a remote location, like that cabin where you have to generate your own electricity.

[Thanks HybridBlue]

Backup DVD burning robot

[Aaron Shephard] at mini-itx.com just finished a backup DVD burning robot based on an EPIA M10000 Mini-ITX motherboard and scavenged parts. A Perl script interacts with stepper motors, LEDs, and sensors through the parallel port on the motherboard. The robot inserts DVDs for burning, flips them for labeling, and stacks completed discs in a pile. Coasters are rejected to a ‘penalty box’ for easy disposal.

We’ve also covered some other optical disc duplicators in the past.

[thanks maxthereal]

Turn your old hard drive into a sander/grinder


[Jipa] over at MetkuMods put up an original re-use for old hard drives: make em into power tools. The tiny servo motor that drives the spindle doesn’t generate much torque, but once the drive is spinning fast enough, the inertial force of the platter is enough to make it usable for small grinding/sanding projects. The platters are re-stacked directly on top of each other to increase strength – we’d suggest a few dabs of epoxy to make em even stronger. Once stacked, a piece of sand paper is cut to size and held on by the center platter washer. [Via hacknmod]