An Open-Source Rotational Casting Machine

September 15, 2011 by Jeremy Cook 28 Comments

[Aurelio] wrote in to tell us about the smartCaster, an “Open source automatic roto-casting machine.” For those of you not familiar with roto-casting, or rotational molding, it’s a process whereby something to be formed is placed into a mold and then melted while spinning. This item is often plastic, but it can be another material such as plaster of Paris or even chocolate.

Naturally, having something made using this process is generally very expensive and generally requires a high volume of parts to be made. The smartCaster Kickstarter project aims to change this. Although in the prototype stage currently, [Aurelio] claims to need only $1571 to finish his project and make it ready for the prospective at-home rotational molder.

Although it’s a much different tool than we see here most of the time, for the right project (custom Easter Bunnies anyone?) it could be quite useful. Check out a video of the prototype in action after the break. Continue reading “An Open-Source Rotational Casting Machine” →

Amp Hour Interviews [Joe Grand]

September 14, 2011 by Mike Szczys 6 Comments

The Amp Hour, a podcast of electronics enthusiasts and professionals alike, just did an epic interview with [Joe Grand]. Along with hosts [Chris Gammell] and [Dave Jones], the discussion runs the gamut of points of interest in the hardware hacking world. The first vignette explores the rise, run, and fall of Prototype This, an engineering-centric TV show that [Joe] did along with a group of various engineers for the Discover Channel. He politely discusses some of the goods and bads of the TV business and how that affected the team’s ability to go into great detail about the projects they were building.

From there the guys discuss the development of Hackerspaces through the years. [Joe] has some concerns about the injection of corporate sponsorships in these DIY spaces and what that may mean in the long run. He then talks about the impending release of his 3-year-long laser range-finder project (we’ve seen a project using a prototype of this sensor). The show is rounded out with discussions about hardware fab houses that [Joe] uses and has used over the years for projects like the Defcon Badges (we loved his Defcon 18 badges).

It’s a great episode so download a copy and set aside about an hour to listen to the whole show.

A No-touchscreen Picture Frame?

September 10, 2011 by Jeremy Cook 8 Comments

Many people have touch-screen devices, however, this hack claims to be the first picture frame to feature a “no-touch” interface. Although someone somewhere certainly has a digital picture frame hooked up to a “Clapper”, we’re going to give [Wasabi] the benefit of the doubt.

After buying a Microtouch kit from Adafruit several months ago with the intention of building something meaningful, [Wasabi] ran into a common problem among hackers, a lack of time. Instead of totally giving up on the device, the decision was made to make it into a simple picture frame. Although the Microtouch features a touchscreen, it also features an accelerometer. With a little hacking, as described in his write-up, the “touchless” picture frame was born. Cleverly, the screen was hidden behind glass, but through this interface, interaction was still possible.

The device itself seems like a great hacker tool, especially at a price point of just under $70. Here’s a hack where “Zork” was ported to this device, but be sure to send us any other projects you come up with using it! Check out the video after the break of this device in action!

Continue reading “A No-touchscreen Picture Frame?” →

Beginner Concepts: MOSFETs

September 7, 2011 by Mike Szczys 12 Comments

[Moser’s] introductory guide to MOSFETs serves as a quick introduction for those unfamiliar with the parts. They fill a similar role as a bipolar junction transistor like the 2N2222, making it possible to switch large loads. But fundamentally they are different. Metal Oxide Field Effect Transistors have three pins for Drain, Source, and Gate instead of the Collector, Emitter, and Base that you may be used to. The Gate is the control pin for the device and offers a desirable advantage over bipolar junction transistors in that it is insulated from the channel. This means that much less current flows into the Gate when compared to the Base of a common transistor, saving power and providing protection to the logic circuitry.

Don’t fret if this makes your head spin. [Moser’s] writeup is short and to-the-point but it’s not watered down. You can get a basic overview and if you care to learn more, he’s linked to datasheets and has basic terminology that is easily clarified with a Google search. One of the most powerful tools that he’s included is the simple MOSFET and driver circuit diagram you see above. This makes it possible to switch incredibly large loads very quickly; the true power of the MOSFET.

Playing Snake With A TV Remote

September 6, 2011 by Brian Benchoff 12 Comments

[vinod] sent in his replica of a Snake game, the game to play on old Nokia dumb phones.

The build is based on a PIC16F877 microcontroller just like previous Snake builds we’ve seen, but [vinod] didn’t use physical buttons in his build. Instead, he used a Philips infrared TV remote to control the game. The infrared controller only takes up one pin on the microcontroller, as opposed to the 4 pins of the easiest four button setup. [vinod] also threw in a simple one-transistor level converter so Snake can be played with a PC via RS-232. With the PIC code included in the build, it’s a great build that reminds us of a more civilized age.

The video of [vinod]’s snake game in action is posted after the break, but we noticed that the snake is allowed to ‘warp around’ the sides of the LED matrix. Some people might consider that cheating but that can be fixed by changing a few lines of code.

Continue reading “Playing Snake With A TV Remote” →

A Ham Radio Receiver, Manhattan Style

September 4, 2011 by Mike Nathan 3 Comments

If you’ve never heard of “Manhattan Style” circuit construction, you’re not alone. Popular in ham radio circles, the process looks nicer than straight dead bug style circuit building, but not as involved as etching your own PCB – consider it a nice middle of the road solution.

This type of construction is often used to build circuits inside enclosures that are made of copper clad, which is a somewhat common practice among ham radio operators. Manhattan Style circuits are built using glued-on metal pads to which components are mounted. One might think that the large pads you see in the image above would limit you to through-hole components, but that’s definitely not the case. A wide array of SMD pads are available in common pin configurations as well, allowing you to use pretty much any type of component you prefer.

While it might not be appropriate for every project you work on, Manhattan Style circuits and copper clad boxes definitely add a nice touch to certain items, like the Wheatstone Bridge Regenerative Receiver you see above.

[via Make]

Coil Gun Revolver

September 2, 2011 by Brian Benchoff 33 Comments

[Sam] sent in a coil gun revolver – a feature we’ve never seen on a coil gun build before. The gun is based on a cheap toy revolver and is powered by a 9 Volt battery connected to an “electrified fly swatter tennis racquet” instead of the usual disposable camera build.

The revolver mechanism isn’t perfect – [Sam] has to advance the chamber with his thumb while the capacitor is recharging. This is only because of the mechanics of the plastic toy his gun is based on, though. He figures a small motor could do the work for him, but he’ll be forgoing that project to work on the MK II version.

Most of the coil gun builds on Hack A Day have been muzzle or breech loaders, so with [Sam]’s revolver we’re probably seeing the evolution of firearms mirrored in coil gun advancements. Does anyone want to take a guess and predict when we’ll see the equivalent of a this .50 caliber beast?. [Sam] says his next project is going to be a rifle, so he might have his work cut out for him.