Measuring How Components React To Extremely Cold Temperatures

July 22, 2012 by Mike Szczys 8 Comments

[Shahriar Shahramian] is playing with some liquid nitrogen in order to see how various components react to extremely low temperatures. After the break you will find forty-one minutes of video in which he conducts and explains each experiment. This does have practical applications. If you’re designing hardware for use in space you definitely need to know how the hardware will be affected. We’ve actually seen test rigs built for this very purpose.

During the presentation he doesn’t water down the concepts observed, including the equations governing each reaction to temperature change. If you’re in the mood for a little bit lighter faire you should check out some of the liquid nitrogen cooking hacks like this super-cold cocktail pops project.

Continue reading “Measuring How Components React To Extremely Cold Temperatures” →

Building A Steam Punk Style Time And Weather Display

July 21, 2012 by Mike Szczys 8 Comments

This is [Pierre Cauchois’] digital weather display. Since weather displays are ubiquitous in this day of smart phones in every pocket he went out of his way to give it a unique look. He started with a wooden voltmeter case, swapping the ancient display for a modern LCD screen.

He used Gadgeteer components for the retrofit. The images for the LCD are stored on an SD card and displayed on demand. Since the digital bezel will be the same no matter what the time or environmental conditions [Pierre] used the power of the .NET framework that drives the system. He made up an image using magenta for all of the dial openings. This way a sprite can be used just for the changing numbers, weather icon, and graphing area.

Looking at all that went into coding the project we think the Gadgeteer components are perfect for those that are well-versed in upper-level languages and don’t really want to deal with low-level microcontroller issues.

[Thanks George]

DMG Lib: Digital Mechanism And Gear Library

July 18, 2012 by Gerrit Coetzee 9 Comments

Reader, [klemens], suggested DMG Lib to us when we posted about a similar site. DMG-Lib is an amazing source of information. It’s primary downside is that a great portion of the text is in a language other than English, though in some ways this is a plus. Latin, Italian, German, and many other languages held the position of being the chief scientific language of the world long before English, and this repository holds entire books about mechanisms in those languages. Some of the books range all the way back to the 1500s. The mechanism animations are very good on this site and play smoothly. While it’s a little harder to search than KMODDL due to the language oddities, it’s still an extremely useful and interesting site to add to the hacker’s information toolbox.

Scratch-built Railroad Crossing Signal

July 16, 2012 by Mike Szczys 7 Comments

At first glance you would think this is the real thing, but [Kevin] built this railroad crossing signal from parts you can find at the home store. We keep seeing traffic lights used as web-connected signaling devices. This would be right at home for that type of setup, but [Kevin] built it with railroad enthusiasts in mind.

He used Google SketchUp to design the frame for the signal, then purchased all of the PVC parts to match those specifications. Some grey spray paint goes a long way to making it look like steel tubing. But this is much easier to work with and he should have no trouble internalizing the wiring later on. The lights themselves are tail lights for a trailer with a decorative trim piece added. He designed his own driver board to switch the lights and ring the doorbell which give the signal some sound. His first version used a 555 timer, this one upgrades to microcontroller. We like what he’s doing in the video after the break, but think the bell speed needs to be doubled for it to mimick the real thing just about perfectly.

Continue reading “Scratch-built Railroad Crossing Signal” →

Repurposing Old HDD Components

July 12, 2012 by Mike Nathan 32 Comments

hdd-stepper

[IronJungle] had an old hard drive taking up space in his workshop, so he took it apart and wrote in to remind us how useful these old pieces of hardware can be. Aside from offering up incredibly strong magnets and donut-shaped mirrors, HDDs also come with a reliable stepper motor in tow.

He pulled theold drive apart, wiring up two of the stepper motor pins to a pair of the drive’s header pins. This allowed him to easily access the signals produced by the stepper simply by hooking up a small JST connector to the back of the drive.

From there, he can use the drive for any number of purposes. For the sake of discussion, [IronJungle] used it to flash an LED as seen in the video below – something he willingly admits is no great feat. However, stepper motors can be used for in a wide array of projects, both simple and complex. Be sure to share your favorite use for salvaged HDD motors in the comments.

Continue reading “Repurposing Old HDD Components” →

Two-stage Rocket Climbs To 15 Km, Promptly Gets Lost

July 11, 2012 by Brian Benchoff 34 Comments

Last month, the Cambridge University Spaceflight society launched two stages of their Martlet 1 three-stage rocket. After seeing our call for rocket builds, they sent in a launch report. We’re glad they did; it’s an amazing piece of work that screams into the atmosphere faster than the speed of sound.

The society is designed the three-stage Martlet 1 with the goal of reaching 15km (50,000 feet) over a launch range at Ben Armine in Scotland. This launch was a test of stage separation, intended to work out any bugs in the system before going to the full-sized rocket.

When Martlet 1 takes off, it’s 1st stage engine fires for 5 seconds and coasts for another 9 seconds. In the video after the break, the guys expected to hear the pop of the second stage igniting after 14 seconds. The team forgot to account for the fact the rocket would be 3km in the air at that time, and thanks to the slowness of sound the second stage was heard though the clouds at 25 seconds after launch.

With rockets, hardly anything goes exactly as planned, so unfortunately the team only recovered the bottom half of their rocket. After searching over 60 square km for the second stage, the guys realized it might be lost to the moors of Scotland. Hopefully the second stage will turn up soon so the full 3 stage stack can be realized.

Check out the launch videos after the break.

Continue reading “Two-stage Rocket Climbs To 15 Km, Promptly Gets Lost” →

Data Mining And Saving Money With Octopart’s Historical Pricing

July 6, 2012 by Brian Benchoff 6 Comments

[Greg Shikhman] is at Octopart this summer as a software development intern. In between the time he’s spending getting coffee for the other devs, he came up with historical pricing for thousands of components available at Octopart

There’s a lot of cool data out there, like this bit of pricing info for a 555 timer. We’re guessing a few people were out of stock of 555s around the end of May, explaining why they were selling (well, available for) $1.68 a piece. If you’re trying to source components, it might be worth your while to check out Octopart’s historical price index. Buying a PIC microcontroller last August was a roll of the dice; in one day the price changed from $5 to just over $2.

With all this data, it’s even possible to data mine for real life events unrelated to shipping and stocking issues. Japanese manufacturer Renesas was hit pretty hard by last year’s earthquake, and this shows up in the historical prices for one of their microcontrollers. Not bad for an intern’s project.