HERF Gun Zaps More Than Your Dinner

March 21, 2011 by Mike Nathan 76 Comments

Instructables user [Jimmy Neutron] had an old microwave sitting around and figured he might as well gut it to build a high-energy radio frequency (HERF) gun.

The concept of a HERF gun is not incredibly complex. Much like your microwave at home functions, a high voltage power source is used to drive a magnetron, which produces micro wave radiation at 2.45GHz. These waves are then guided away from the magnetron using a waveguide, towards whatever the target might be. These waves then energize the target in a similar fashion as the water molecules in your food are energized during cooking.

[Jimmy] has not quite finished his HERF gun as he still needs to build a waveguide for it and then safely mount it for use. In the meantime, check out the pair of HERF guns we found in the videos below.

As a parting note, we must stress that building a similar device is dangerous, very dangerous – especially if you do not know what you are doing. Microwaves contain high voltage components, and exposure to microwave radiation can be deadly under certain circumstances. Stay safe!

Looking for more microwave fun? Check these out!

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Laser Microscope Projection

August 21, 2010 by Caleb Kraft 35 Comments

looks totally safe to me

Ok, we’ll start this off by saying, looking at lasers can damage your eyes. Be careful. Now that we’ve got that absolutely clear, we couldn’t help but find this super quick and dirty laser microscope fascinating. Basically, they are just pointing a laser through a drop of water suspended from the tip of a syringe. The image of the contents of the drop are projected on a nearby wall. The drop seen in the video after the break was taken from a potted plant and you can see all kinds of life squirming around in there. Just don’t try it with this laser.

[via HackedGadgets]

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Lawnmower+stake+rope=Analog Robotic Lawn Service

April 26, 2010 by Mike Szczys 75 Comments

[youtube=http://www.youtube.com/watch?v=3tNVOhtvPEw]

[Kirov], a regular reader and one of our most notorious commenters, tipped us off about this lawn mowing hack. On one hand we’re wary that this is bait for a huge flame war, but on the other hand it’s a hack that brings a smile to our mischievous faces. By pounding a stake into the center of the yard and connecting a mower to it with a piece of rope, [Korey99] has achieve an automated lawn mower. He tied the self-propelled mower’s throttle bar down to make the machine run unattended. There’s no kill switch or any kind of remote control for the lawn mower so we wonder what happens when the rope gets all wound up?

Ping-pong Launcher Your Wife Can’t Know About

November 2, 2009 by Mike Szczys 27 Comments

ping-pong-ball-launcher

Sometime the projects you see at the local hacker space are better left a secret when you return home for the evening. Case in point, this ping-pong ball launcher that can put holes in a sheet of OSB. The projectile is made more lethal because the ball has been injected with water to dramatically increase the density. Compressed air is used to propel it from the 14 round magazine with devastating effect.

We’ve embedded a video of the gun being fired after the break. The creator, [Ron Kessinger], demonstrated this at a Denver hacker space called Club Workshop. We’re hoping there’s no plans for turret automation because this thing’s dangerous! Either way, the significant other who usually watches out for our safety would never approve. Continue reading “Ping-pong Launcher Your Wife Can’t Know About” →

Refillable Canned Air

July 14, 2008 by jimmierodgers 31 Comments

While not very technical, [3eff_Jeff] posted an interesting modification to an empty air canister that makes it refillable. He was tired of drilling holes in the ozone, so he carefully drilled a hole into the top of the can instead. In the name of caution, he made sure the can was completely empty first by tying the trigger down with a rubber band. After waiting a while he carefully drilled the hole using an oil lubricant, and then epoxied in a Schrader valve from a leftover bike tire tube.

Due to compression of the air as it is pumped into the can, it becomes quite warm. He found that if the can is allowed to cool to room temperature, the air would become very cold once leaving the canister, which would cause condensation problems. So he uses it right after filling, and then empties it out when not in use.

We do not recommend anyone trying this, but it is a unique way to make a commonly used disposable resource in the computer field reusable. If we can use something more than once, we’re definitely for it. That’s why we support recycling components that would otherwise make their way to the landfill.