Hot Mad Science Posts

DIY Blacksmithing: Forge Your Own Steel at Home!

Metal is a great material to work with. It's rigid, tough, malleable and conductive, but sometimes the part we need doesn't exist in any store. In order to create custom pieces, you need to either melt the metal and cast it in a mold, or heat it until it's soft enough to shape with your hammer. Properly melting metals can be a bit dangerous in our home shop, but we can make a coffee can forge for all of our home blacksmithing needs.

Arduino Air Force: DIY Robotic Cardboard Quadcopters

You're hellbent on taking over the world, but one race of robotic minions isn't enough for you. With your hexapod robots acting as your ground forces, it's only natural to take to the skies. These cardboard quadcopters are the perfect air force for you. Combined, you are mere steps away from starting your evil takeover. Now you just need some water bots. The cardboard flying quadcopters are built around the MultiWii platform with the twin power of Processing and Arduino, so they are actually ...

How To: Build Your Own Mini Altoids Guitar Amp for About $5

I love making beeps and bloops with the Arduino pitches library, but sometimes archaic 8-bit tunes just don't cut it. Whether you want your robot to terrify your enemies with a demonic synthetic voice, you just need a pocket boom box on the go, or you want to a miniature guitar amp, a simple LM386 amplifier can crank up those signals loud enough to play through any speaker.

How To: Design Your Own Custom Arduino Board Microcontroller

Microcontrollers are great. You can do anything from water your garden to catch wildlife trash diggers in the act—and on the cheap. I prefer to use the Arduino microcontroller because of the large and helpful community built around the website. Though it is my favorite, there are some drawbacks to using an Arduino board in every project. It gets expensive, the board can take up too much space, and the rat's nest of breadboard wires are a pain to repair.

Spice Rack Explosives: How to Make Gunpowder with Salt and Sugar

The best chemistry experiments are those you can perform with items already laying around your house. With only some sugar, salt substitute and an instant cold pack, you can make your very own gunpowder! Being able to make homemade gunpowder without a trip to the store can be a lifesaver, no matter if it's just for testing out a Civil War-era musket, blowing up stubborn tree stumps, or preparing for battle when imperialists overrun your country.

Glass Cutters Are for Tools: How to Dissolve Glass Using Sodium Hydroxide

Glass is one of the least reactive substances known to chemistry. It is the standard container material for almost all lab chemicals because it's so inert. But there are a couple of substances that have strong reactions with glass. Sodium hydroxide, aka solid drain cleaner or lye, can easily be stored in glass as a solid, but when molten, it reacts violently with glass and can actually dissolve it away! So, the next time you clog up your drains with broken glass beakers and flasks, rest assur...

Fire Texting: How to Write Secret Messages with Fire

Writing secret notes with lemon juice was one of my favorite pastimes as a child. All it took was a small flame to lightly scorch the paper and reveal the hidden message. Now that I'm tall and pay bills, lemon ink just isn't exciting enough anymore. Luckily, we can use another kind of invisible ink to write in fire! By using the saltpeter, we can whip up invisible fire ink in no time.

News: This DIY Mini Tesla Coil Packs 380,000 Volts of Lightning

At one point in time, Tesla coils were actually used for things like wireless telegraphy and electrotherapy, but as technology advanced, they shifted to a slightly more enjoyable purpose—entertainment. What's even more entertaining than using a Tesla coil? Building your own. One of the best portable Tesla coils out there is this mini acrylic version by Daniel Eindhoven, aka TeslaCommander. It's made almost entirely of acrylic plastic, minus the steel sphere, and copper wire and tubing. When t...

How To: Create a PCB Etchant That Automatically Improves After Each Use

Etching your own circuit boards is tons of fun, but etching requires strong chemicals to dissolve the copper plating on blank circuit boards. The normal ferric chloride solution works well, but can be expensive and leaves permanent stains. Luckily, we can whip up our own etchant at home with everyday chemicals! Better yet, our new etchant will turn an eerie green color rather than the dull brown of ferric chloride.

How To: Find Hidden Blood Splatter Stains on Your Walls with This Infrared Photography Hack

I'm sorry to say, but Dexter Morgan hasn't thought of everything. Just because he's the best blood splatter analyst in the Miami metro area, doesn't mean he can't be taught a thing or two about blood. In fact, I'm sure this is something he'd be glad to know. Spotting a bloodstain is pretty easy at a crime scene, especially when there was no attempt to cover it up. When the scene has been wiped clean, there are still ways for forensic investigators to detect washed away blood, like using a rea...

How To: Build a Long Range Laser Spy System for Eavesdropping on Your Neighbors

Eavesdropping from a distance can be tricky because it usually requires some sort of bug or transmitter. It's easy to transmit audio through lasers, but you can also use lasers to build a microphone that picks up audio from a distance. LucidScience built the Laser Spy System for about $20. To make your own, you'll need a cheap laser pointer, an NPN phototransistor, a headphone amp, and a few other small pieces listed below. A light-to-sound circuit is installed in a small plastic box with the...

News: This Real-Life, Working WALL-E Robot Is Absolutely Perfect (And Built Entirely from Scratch)

Want to build your own life-sized, working replica of WALL-E? Be prepared to take on a second job! Mike Senna spent two years perfecting his own version, working 25 hours a week and totaling somewhere around 3,800 hours for the whole project. He had no blueprints to go by, so he spent a lot of time watching the movie over and over to get everything just right. The video below shows some of the construction; skip to about the one minute mark to see WALL-E in action.

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