What better way to kick off your summer than building something to dazzle your neighbors with a symphony of booms, zaps, thumps, and other assorted better-call-the-ambulance noises? Read on as we highlight 10 geeky and dangerous projects.

While geeky projects of all stripes are fun there’s just something about projects that require safety goggles, protective clothing, and potentially a blast shelter, that make us pine for a youth spent with chemistry sets and willing neighbors as test subjects. If you’re looking for some living-on-the-edge geek fun for your Memorial Day activities list, look no further.

The following projects range from “Don’t forget to wear your safety glasses!” to “Wear a helmet and update your Will!”—consider yourself suitably forewarned and don’t do anything Chuck Yeager wouldn’t do.

Build a 1W Blue Laser Torch

What’s more fun than shining a laser on things? Shining a laser on things and lighting them on fire. This build is not for a beginner both from a technical stand point and from a safety standpoint. If you can handle the build, however, we’d hope you’d have enough common sense to buy laser safety goggles.

Complete Your Laboratory Décor with a Jacob’s Ladder

Many of the things in this roundup are dangerous in the sense that you could accidently light yourself on fire or shine a laser into your eye. Building a Jacob’s ladder is a totally different kind of dangerous and well into the “if you screw this up you will short circuit your heart and die” realm. It’s an absolutely awesome project if you’re into playing with electricity but it’s definitely not for beginners. Read more about building a Jacob’s Ladder here.

Build a Skull Crushing Slip ‘n Slide of Epic Proportions

They just don’t make Slip ‘n Slides like they used to. Armed with a few rolls of heavy polymil painter’s tarps, a hose,  and, for the adventurous, some soap or lubricant to really enhance the speed, you can recreate the daring of your childhood Slip ‘n Slide adventures on a much more teeth shattering scale. If the simple plastic sheet and a hose isn’t enough for your geeking-out tastes, check out this guide to a self-watering slip and slide.

Turn Yourself into a Human Firework with a Fire Wire

You might associate Firewire with a type of port/cable combination found on Mac computers but it’s also a term used for a flaming ball of steel wool attached to a wire. You read that correctly, steel wool (under the right conditions) is highly flammable and when you spin it generates an amazing show. Watch the above video to see it in action and then hit up this link to learn how to do it.

Create a Real Life Sound Visualizer

Want to play with fire but not in a way that might shower your lawn with sparks and set your hair a blaze? Build a Ruben’s Tube. Ruben’s Tubes are a clever way you can use fire to visualize sound waves. It’s a classic physics experiment where in flammable gas is pushed into a tube with dozens of tiny holes drilled in it. The gas is lit and then sound is pumped into the tube. This is where the awesomeness happens.

Sound occurs when something alters air pressure (thunder, for example, is so amazingly loud because the lighting that causes it quickly and forcefully alters the pressure in a relatively small area). In the case of the Ruben’s tube, thanks to the flames, we get to see the actual pressure changes induced by the sound waves. Science is awesome.

Build your own Ruben’s Tube with this tutorial.

Recycle Your Way to DIY Lawn Darts

In 1988 Lawn Darts were banned by the Consumer Product Safety Commission for being what amounted to a giant finned dart throwing game marketed as a fun backyard activity. If you’re hankering for a you’ll-put-your-eye-out long weekend moment, you just have to turn to the DIY crowd. You’ll find some simple bottle-based darts—seen in the photo above—here or, for the more adventurous that want to build a superior dart, you can get more advanced plans here.

Build a High Speed Spear Thrower

What’s that you say? Lawn darts seem fun but too tame for your projectile interests? Fair enough. Skip the homemade lawn darts and jump right into the big leagues of pointy-injuries-waiting-to-happen by building an Atlatl, an ancient spear throwing tool that increases the force of a human throw so much that a spear/dart can be thrown up to a hundred miles per hour. Watch the video above to see how it’s done or hit up this link for detailed instructions.

Build a Jam Jar Jet

Jam Jar Jets are the DIY mad scientist version of valveless pulse jets. It’s the simplest jet design around and doesn’t require forward motion to sustain combustion. If you’re interested in the raw science of it, hit up this Wikipedia link. If you’re interested in building one in order to earn the bragging rights of “I once built a jet engine in my garage”, watch the above video to see how and then read more at this link.

Lay Siege to the Neighborhood with a Trebuchet

Trebuchets were a medieval siege weapon of amazing power. A full size trebuchet is easily capable of throwing a grand piano hundreds of feet. While it’s unlikely you’ll build a full size replica—as seen in the NOVA video above—you can easily build a small working model capable of the kind of destruction you’d better have a big back yard to contain. Check out these plans here to get started. If you’d like to keep things on a scale that won’t destroy your neighbor’s car, check out this mini Altoid Tin model.

Defend Your Lab from Zombies with a Golf Ball Gun

Spud guns are a dime a dozen. Golf ball guns are where the real zombie defense—and head injury—potential is at. Where can you find the plans to turn a bunch of PVC, an air compressor, a box of golf balls and a can of Axe body spray into a skull-crushing projectile launcher? Right here.

Work your way through this project list and you’ll end up with epic tales of mad scientist glory to share with your grand children or, at minimum, a plate in your head to tap on as you warn then sternly about the importance of helmets. Have a fun (and dubiously safe) project to share? Let’s hear about it in the comments.


Profile Photo for Jason Fitzpatrick Jason Fitzpatrick
Jason Fitzpatrick is the Senior Smart Home Editor at How-To Geek. He has over a decade of experience in publishing and has authored thousands of articles at How-To Geek, Review Geek, LifeSavvy, and Lifehacker. Jason served as Lifehacker's Weekend Editor before he joined How-To Geek.
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