Pyramidal holographics have become popular fast, with crowdfunding projects offering you ways to get into the game for just hundreds of dollars, but here is a way to put together your own small-scale version effectively for free.

Required tools: a smartphone, compact disc case, graph paper, pen, scissors, knife, tape or superglue. Basically, you cut a partial pyramid from the clear material, fasten it together, set it on your phone, and load up a video that turns those surfaces into four-way reflectors simulating the visual experience of objects moving in midair.

Critics will argue that this is not a true hologram and that is absolutely true, but the effect is nonetheless extremely compelling, and you can use it to animate not just the examples above but basically anything you want as well. The next step: scale things up and turn a television or computer screen into your base and buy a larger surface for the reflection.

Or, for additional easy fun, try this hand-drawn hologram tutorial (above) – it won’t be quite as visually complex or impressive, but it is still a neat trick to show friends or kids.

The post DIY Holograms: Hack a Phone & CD Case to Make 3D Videos first appeared on Gajitz.

3D printing guns is one thing, but 3D printing railguns that can fire metal projectiles at 250 meters per second is quite another, none of which stopped this creator from making his video game dreams a physical reality. While it may look like a geeky dress-up accessory you would not even notice at a comic convention, this is the real deal.

The weapon in question has six capacitors weighing 20 pounds and providing 1,800 joules of energy per round. Parallel electrodes fire an armature bullet while an Arduino Uno R3 monitors charging levels and temperature.

3D CAD drawings show how the thing was designed and built and test fires show the contraption denting steel and plywood. The projectiles do not survive the mission.

You can see more bits and pieces of the construction process and components in this image gallery. If you ask really nicely, its maker may even let you sneak a peek at his construction documents or build instructions.

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In an informal and spontaneous contest to see who could share the geekiest key holder from their office or coworking space, a series of Redditors (on /r/geek) submitted a great series of photos featuring clever (and useful) key storage systems – you can ignore the vote count, though, and pick your own favorite, as each has features to recommend it (though a few may have bugs as well).

First and by far the most popular, the top-voted design features ethernet cables looped and plugged into a 5-slot box. While more of an aesthetically-inspired setup and not technically active as such, commenters suggested modding the device to register which keys are in place at any given time (via zedpee, who was ‘gilded (given Reddit Gold) for his efforts).

The Keyboard 2.0, meanwhile, actually works not only to tell you whether keys are plugged in but also has a locator system that lets you find your keys when you misplace them around the office – its plug-and-play interface also looks somewhat more robus, using traditional snap-in key ring connectors rather than breakable plastic (via h0uz3_).

Finally, no geek collection would be complete without something using LEGO, perhaps referencing Star Wars and/or including a comic book superhero, so this last submission conveniently does all three, with detachable blocks that let you snap in your key chain easily and without requiring much extra pocket space (via Spaz_Chicken).

The post DIY Hackers: 3 Geek Key Holders for Shared Office Spaces first appeared on Gajitz.

An all-in-one, self-service solution for creative people who want to paint themselves permanently, this device puts the power (and pain and risk of mistakes) in your hands, for better or worse.

Developed by Jakub Pollág of the Royal College of Art, the Personal Tattoo Machine was inspired in part by the innovative ways prisoners create their own do-it-yourself machines with limited resources behind bars.

In the creator’s own words: “Personal Tattoo Machine democratises the tattoo industry. It puts a tool used only by a limited group of people into the hands of enthusiasts, who are seeking an alternative and unique way to permanently mark their meaningful memories onto their skin.”

For some, tattoos are about recording experiences or self-expression, not about a perfect image drawn by an artist. For others, they would rather take the risks and responsibilities on themselves instead of putting them in the hands of professionals.

Currently in a prototype phase and using 3D printed parts, the device has already been used for dozens or works on dozens of people. When it comes to commercial production, the kit will include sterile needles, tubes and inks as well as gloves, antiseptics and other health-related accessories and instructions.

Unlike most commercial equivalents, he offers only one (smaller) size, emphasizing that this is about the process – people can build up what they want over time rather than laying it on thick to begin with. “This machine is not aiming to replace tattoo parlours. It’s there to offer a more personal option. If you want a realistic portrait of your, let’s say, cat, you should still go to a tattoo parlour and not use this machine.”

The post DIY Tattoo Machine: Trust Yourself for Your Own Body Art? first appeared on Gajitz.

Breaking down the Internet of Things into a set of user-friendly building blocks, this kit lets you make your own internet-connected creations right out of the box and without any coding experience, all thanks to SAM.

A set of physical modules compliment a software package that make it possible to link inputs and outputs with the cloud and apps, things like buttons, pressure sensors, thermometers tied to lights, buzzers and motors. Each block has its own wireless connection and battery and can thus operate independently as needed and completely wirelessly as well.

Bluetooth conveys sensor-captured data to your device, which then communicates demands and tasks back outward. You could program your doorbell, for instance, to prompt an unconnected camera to take a picture of your visitor. A lot like ‘If This Then That’, you can create simple or more complex chains of consequences for actions and responses. Expert users can also peel back the wrapper casing to reveal the electronics within in order to better understand (or hack) them.

From its creators: “There was no really easy way to create a product, an app, or a piece of art using electronics and coding. I thought this was crazy as it basically meant cutting off the majority of the designers who haven’t had the luxury to have a technical education.”

“[The Internet of Things] is becoming essential. The boundaries have blurred between the world of physical and digital products, and the potential to connect one thing to another is huge. This doesn’t just mean physical objects talking to one another but talking to broader services and experiences, which might only exist digitally.”

The post DIY IOT: Toolkit for Creating Your Own Internet of Things first appeared on Gajitz.