Quoth The Raven: Hack Some More

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There are people who buy a cheap sack of candy and dutifully answer the door on Halloween. Then there are people like [Peter] who spend the whole year planning for the next year’s Hollywood-style front yard theatrics.

He added an animatronic raven to his show a few years back. It has been wildly popular and it’s not hard to see why. The bird is well engineered, well built, and the performance is very realistic. [Peter], who is an FX supervisor in the film industry, has posted a build log that takes us through step by step. This creepy performer can move its head up and down, side-to-side, and even rotate at the neck. This all happens while the beak synchronizes with talking. We marvel at the precision machining that was done to make the frame facilitate movement.

The body itself is made of fiberglass covered with feathers. [Peter] covered the completed mechanics with clay in order to sculpt the final body shape. This was used as the mold by covering it with fiberglass release and then fiberglass fabric. This process produced a very light weight and accurate shell with a minimum of effort; something we’ll keep in mind for future projects.

Take a look at a bit of video after the break. You can see the whole show from past years over at [Peter’s] site. We’ll be doing a couple of follow-ups covering his animatronic skeleton (the raven’s partner in crime) as well as the interface he uses to control and sync the voices to stay tuned! Continue reading “Quoth The Raven: Hack Some More”

RCDC: DC Motor Control Via Servo Signals

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[Spikenzie]  has put together this nice kit for controlling a DC motor with RC servo signals. He’s using a PIC12F629 to convert the signal to PWM. As you can see in the video above, it seems to work quite well. It is in a neat and tidy package and available as a kit. We have to admit though, what caught our eye was the prototype. Even though it is a kit for sale, it looks as though they plan on releasing the PCB files and code.

Humanoid Robot + Homebrew Waldo = Big Smiles

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Robot enthusiast [Vitalijus Rodnovas] built this rig to allow a humanoid robot to mimic his own body movements in real time. [Rodonovas] refers to his man-machine interface as a “master-slave suit,” but elsewhere this is often called a waldo after a prescient 1942 [Robert Heinlein] novella. This project page is slight on details and is mostly written in his native Lithuanian, but the pictures speak volumes, and with a little help from Google Translate we can learn the essential facts: The robot itself is a commercially-available kit, the Kondo KHR-1HV from Japan. The custom-built harness uses a collection of surplus Soviet-era military potentiometers (acquired on eBay) to read the positions of his elbows and shoulders, then an ATmega8-based interface board translates these readings into motion commands sent to the robot’s onboard controller. Some additional notes and code can be found on the RoboSavvy Forum.

Does it work? Just watch. His grin as the video progresses is infectious!

Hack a Day has previously covered other Waldos, but this latest deserves style points for its lightweight simplicity.

Experimental Robotic Platform

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Introducing ERP: Experimental Robotic Platform. This is an open source, modular robotics platform that, as you can see above, didn’t fair too poorly in the Robogames 2009. [John] has been working on this platform for roughly 2 years and states that it will never be “finished”. It is a development platform, and is always changing and being updated.  You can follow along on the project page to see the major design changes as they happen, such as the wheel suspension system cut from a single piece of plastic. All of the pieces, schematics, and software are available for download. Be sure to scroll down and see ERP’s reaction to some of crabfu’s inventions.

Lego Modded Antenna Tuner

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This antenna tuner is controlled remotely using geared motors and legos. The tuner needed to be closer to the antenna for performance reasons. This created a problem; most of the radio gear is inside while the tuner is outside. The gear motors and Legos combine to form a closed loop servo, operating two air core caps and an inductor switch. A control box placed near the radio is hard wired to the modded tuner outside. We would like to see something like this under gesture control using the Wii MotionPlus + Arduino.

Clever Stair Climbing Robot

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Stairs are one of the most commonly faced mobility challenges for a robot. This robot’s design eliminates the need for a complex drive train or computer, and instead uses a clever mechanical design to climb stairs. Version three of the robot uses five servos modified for continuous rotation, a Picaxe28, sharp IR sensors, and bump sensors.

[via BotJunkie]