Coil Gun Speed Meter

_DIY_bullet_speed_meter (Custom)

One of the best parts of building a coil gun is seeing just how fast you can get that slug to move through the air. [Daniel] built this speed meter to be able to see exactly that. It is comprised of two optical sensors, one at each end of a barrel. As the projectile passes them, its speed is calculated using an Atmega16. Since the distance between the sensors is pre determined, its only some simple math to figure out the speed of an object passing between them. The result is then displayed on a nice looking blue LCD.

If the blue accent lighting and acrylic stylings look familiar, that’s because we’ve seen [Daniel] before. He’s the one that built the portable coil pistol.

[via HackedGadgets]

Homemade Bokode

[vimeo http://vimeo.com/6803291%5D

We’ve recently been getting a lot of new comments on our Bokode post from a while back, and with good reason.  [M@] has managed to find a way to replicate Bokode at home, using $0 worth of equipment (before the price of microprint). To accomplish Bokode at home, it seems all you need is and old webcam lens assembly and an LED.  Of course the his version is not as thin as a regular barcode so it probably wont be replacing anything in the near future, but the concept of from MIT to home within such a short period of time is amazing.

Jet Powered Hijinks

[youtube=http://www.youtube.com/watch?v=tjS8btFb9RA]

This jet powered carousel is brought to you by the Madagascar Institute. They convene, or collide, to create large scale art, sculptures, and rides. This one seems to fit the last definition. The two gentlemen are strapped to a jet powered carousel. It actually looks pretty fun, but we would have been needing some fresh shorts after the jet bursts into flames near the end. He didn’t seem too concerned, he wasn’t screaming and flailing his arms at least.

The Incredible Breakfast Machine

A lot of us skip breakfast in the morning, be it because we don’t have time to make something, don’t have the patience, or for some other reason. Yuri Suzuki and Masa Kimura are aiming to make your breakfast a little easier, a little quicker, and a lot more interesting. Their latest project is a Rube Goldberg-like machine that does everything from fry your eggs to brew your coffee. The coolest part about this project is it was built with the help of the public. The two designers put out an open invitation for people to come help in constructing the device at Platform21, a publicly accessible design forum in Amsterdam. Now if someone would tie this into an alarm clock, we could all wake up to the smell of toast and coffee instead of the super loud 140db alarm clock or the confusing (albeit effective) wake up machine.

Cheap Yaris Cabin Filter

Cheap-Yaris-Cabin-Air-Filter (8)

[Jake] never ceases to amaze with his inventions, from his Powered respirator to his Steampunk LCD and more. Today he proves that not every hack has to be an amazing one requiring hundreds of hours, tons of soldering, and an Arduino. Instead, he was tired of being charged $50 for a $5 cabin air filter. With a quick squeeze he had access to the filter bay. It was only a matter of finding a similar filter at a home improvement store and then using a scrap wood jig, he could cut and glue his own filter. It’s stuff like this that tends to make us think, what else are we getting ripped off on?

Virtual Pool, Real-world Interface

[youtube=http://www.youtube.com/watch?v=2Wc_DXGe2fQ]

Sunday we saw robots playing pool and an augmented reality pool game. Today we’ll complete the pool trifecta: virtual pool using a real cue stick and ball in another vintage video from Hack a Day’s secret underground vault. The video is noteworthy for a couple of reasons:

First is the year it was made: 1990. There’s been much buzz lately over real-world gaming interfaces like the Nintendo Wii motion controller or Microsoft’s Project Natal. Here we’re seeing a much simpler but very effective physical interface nearly twenty years prior.

Second: the middle section of the video reveals the trick behind it all, and it turns out to be surprisingly simple. No complex sensors or computer vision algorithms; the ball’s speed and direction are calculated by an 8-bit processor and a clever arrangement of four infrared emitter/detector pairs.

The visuals may be dated, but the interface itself is ingenious and impressive even today, and the approach is easily within reach of the casual garage tinkerer. What could you make of this? Is it just a matter of time before we see a reader’s Mini-Golf Hero III game here?

Defocusing LED Clock

[Dennis] has created a well-documented and very beautiful clock in his latest project. This clock stands out from the other clock projects we have covered with its unique display. The seven segment LED displays mounted on a sled that moves them back and forth behind an array of fiber optic lenses, effectively taking the display out of focus at certain points. Currently, a Dorkboard controls the sled, moving it at random intervals. The case is machined and polished aluminium, the top buttons are ball bearings.