Closing in on Nixie cuff links

It’s not Nixie cuff links yet, but we’re seeing a lot of potential for a few very classy accoutrements with [thouton]’s Nixie tube necklace.

The build was inspired by this much clunkier necklace that found its way onto the MAKE blog. Unlike the previous necklace, [thouton] used a much smaller Mullard ZM1021 indicator bulb. Instead of the normal 0-9 digits in a Nixie, this tube displays only A V Ω + - % and ~, betraying its pedigree as part of the display from an ancient multimeter.

To power the bulb, [thouton] is using a single AA battery and a boost converter salvaged from a camera flash unit. All the circuitry is on a little piece of perfboard encased in a handsome aluminum tube. Power is delivered through two terminals with a bit of audio cable standing in as the chain of the necklace. We suppose this could be re-engineered to use a coin cell battery; although a coin cell doesn’t offer as many amp hours as a AA cell, [thouton] is confident the AA will last for a few days. A coin cell would be more than enough for a night on the town, though.

Rabiscoscopio – Oscilloscope drawing made easy

Rabiscoscopio

If you own an oscilloscope, sooner or later the urge to see something other than signals on the screen will strike. Some people ignore the urge and go about their normal business while others give in, spending hours carefully crafting images, games, and more. The process is time consuming and tricky as our own [Kevin Dady] discovered, but rewards come in the form of geek cred and are hard to pass up.

[Alex] wanted to draw on his oscilloscope, but decided that he would try something other than the microcontroller-based solutions we have seen in the past. He figured the easiest and most accessible way to draw on the scope was with sound, so he whipped up a small application he calls Rabiscoscopio to do most of the work for him.

He starts off by drawing an image using a single line, saving it as an SVG file. This image is converted into an audio file by Rabiscoscopio, which can then be fed directly into his oscilloscope from his PC. That’s all there is to it – it really doesn’t get much easier.

While you could claim that [Alex] is cheating his way through the oscilloscope drawing process, we think his application rocks – after all, hacking is about making your technology work for you rather than the other way around.

Give Rabiscoscopio a try and post the results here or in our Flickr stream – we’d love to see what you guys come up with.

In the meantime, check out the video below to see [Alex’s] attempt at replicating the Garoa Hackerspace logo on his scope.

[Read more…]

Recorder controlled Snake game played on a Nokia 6110

Dig out an old cell phone, hit the dollar store for some plastic recorders, and build this sound controlled snake game for your next party. The project will be a snap for those comfortable working with microcontrollers, and a great learning experience if you’re looking to try your first Arduino project.

[László] and his friend call the project the Snake Charmer. As shown in the clip after the jump it uses music notes to direct the path of the solid line in the classic cellphone game of snake. But this isn’t just some PC-based rip-off. They’re playing on the actual cellphone. A camera points at the screen to project it for the enjoyment of spectators. The control scheme uses relays soldered to the pads of the four directional buttons. The pitches are being detected by a Max/MSP program, with the corresponding commands pushed to the Arduino via USB. Yep, it’s overkill but the point was to get this up and running quickly and with a minimum of work. We’d say they succeeded.

Actually, now that we think of it, this isn’t a two player game. Perhaps the recorder control concept needs to be applied to a more modern version of the game.

[Read more…]

Who needs mecanum wheels?

Skills are all that’s needed to solve a problem. Take this four-wheeled robot as an example. [Michal Zalewski] wanted it to be omnidirectional but wasn’t very satisfied with the concept of mecanum wheels and the like. So he designed a chassis with wheels at each corner that can pivot as one to change orientation. The image may look like a rendering at first glance, but this is actually the physical prototype. See what we mean about skills?

Okay, so the robot design is pretty cool. But we’re more excited about the build process. We’ve looked at [Michal’s] work before. He wrote a thorough guide about CNC mold making. These parts are all cast from epoxy. This starts with a rough milled mold, which is given a second pass for the fine details before being painted with a release agent and used to make a silicone mold. From this the parts are produced. Check out the Flickr set showing the casting process for the planetary gear box on each motor. If only these results were as easy to achieve as he makes it look.

[via Reddit]

Sliding camera mount is good enough for amateur photography

[Unihopper] built this sliding camera mount to add some motion to his freestyle unicycle videos. It’s extremely simple, but still pulls off a pretty nice effect as you can see in the clip after the break.

The image above shows the mount without a camera attached.  You can see the threaded peg on the block in the foreground which is used for that purpose. Felt has been wrapped around the base of the block, which rides in a wooden channel. The string, which connects to an eye hook in the wood block, is attached to a spool on the far end of the plank. A K’nex motor drives that spool, slowly sliding the camera toward it.

Unlike other toy-based sleds, the use of a track system helps to maintain proper orientation of the camera. Obviously this isn’t going to achieve the perfectly smooth and precise motion you’d get out of a sled system like this rail and linear bearing version. But honestly, most of us don’t have cameras of the quality to warrant that type of high-end system. [Read more…]

Meet the TM65 liquid propellant rocket engine

While we’re reluctant to say it for fear of being misinterpreted, the new liquid fuel rocket engine being built by Copenhagen Suborbitals is one of the most impressive, daring, and nearly the sexiest machine we’ve ever seen. Although the engine hasn’t been fired yet, [Peter Madsen], Chief launch vehicle designer at Copenhagen Suborbitals, gives an amazing 18-minute-long rundown of the function of each and every tank and tube of the TM65 in this video.

When the TM65 engine begins its firing sequence, valves attached to tanks of alcohol and liquid Oxygen are opened. The Oxygen pours directly into an injector manifold that atomizes the liquid in the combustion chamber, while the alcohol makes a much longer trip down to the engine bell, flowing between the double wall of the chamber and nozzle for cooling. Once the alcohol and Oxygen in the combustion chamber ignite, two gigantic tanks of Helium are opened and the gas is forced down to a heat exchanger at the end of the nozzle, increasing the temperature and pressure of the Helium. The Helium is then routed to the tanks, pressurizing them and forcing fuel and oxidizer into the combustion chamber at 40 liters per second. This entire process happens in only eight seconds; after that, the rocket attached to the TM65 will be on its way upward.

We’re not going to say the TM65 is the best engine ever seen on Hackaday; we’ll leave you to decide that. We can’t wait for the video of the test fire to hit the Internet, though.