Giving Life To An Undead Baby Doll

October 22, 2014 by Sarah Petkus 3 Comments

If carving a pumpkin this month is too passé for you, take a shot at [Jason Suter’s] instructable and build an animatronic legless zombie child that will surely creep out anyone who has a fear of dolls or other vacant-faced toy babies.

Beginning with a sacrificial doll, [Jason] dismembers all of the limbs and head from the torso in order to make room for the robotic upgrades. The servo motors which animate the new wooden dowel bones are mounted to a chassis cut with a CNC machine. [Jason’s] instructions include some nice diagrams demonstrating how the points of articulation at the shoulders and elbows work in conjunction to produce different flavors of crawling and dragging.

To top it off, the head is attached to its own mounting plate with tendons that rock back and forth in a miserable undead sort-of fashion. As an added nicety, he explains how to install a bluetooth module into the circuitry so he can tweak and upload his example code to the Arduino brain remotely without needing to get his hands near it. There is of course some additional melting, painting, and doll torture required to achieve that rough-up undead look… but that’s all just icing on top of a well executed piece of animatronics.

In his video [Jason] gives us an overview of his zombie’s build and also shows it in action:

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Baby Quadruped Robot, Learning To Walk

October 22, 2014 by Rich Bremer 11 Comments

We’ve all seen videos of those crazy Boston Dynamics running quadruped robots that can reach up to 28 mph. Those things are amazing and it’s almost impossible to imagine how to even start building one. [Max] loves his robots and wanted to build a quadruped but, being a robot hobbyist, didn’t have the serious cash needed to make an extravagant robot like those of Boston Dynamics. Instead he started bridging the gap by designing a quadruped robot that is a little bit slower and tons cheaper.

[Max] designed all of the mechanical parts himself. After weighing the advantages and disadvantages of different materials, he decided that the frame would be made from 5mm acrylic sheet. The main body of the robot has acrylic ribs that are spaced apart by threaded rods. Twelve RC servos make up all of the joints, 3 in each leg. Notice in this photo how there is one servo that immediately rotates another servo. To support the other side of the rotating servo, [Max] epoxied on a T-nut, stuck in a short length of threaded rod which is then supported in the frame by a ball bearing. Simple and effective! The upper portions of the legs are also made from acrylic sheet and the lower legs are from a cheap camera tripod. Rubber feet ensure a slip resistant stance.

All of the servos are controlled by an Arduino Mega. [Max] is currently writing a sketch that will perform the complex math and determine coordinated servo motions for movements us humans take for granted, like ‘walk forward’. As you can see in the videos, [Max’s] robot won’t be catching the Boston Dynamics’ Cheetah any time soon but he is off to a great start.

Future plans for this project include bluetooth control and integrating the ultrasonic sensor proactively installed in the ‘head’ of the robot. Check out the videos after the break. [Max] is looking for some feedback on his project. We here at HaD think this needs a great name. Let’s hear some suggestions in the comments…

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Robot Arm You Can Build At Home

October 19, 2014 by Rich Bremer 34 Comments

[jjshortcut] has created an easy to make robot arm that has 6 degrees of freedom. There is not much to it, the frame is made out of 4mm thick hardboard, hobby servos provide the power and a handful of hardware holds it together. The frame has been successfully cut out on both a laser cutter and a cnc router, making this design even more obtainable for any aspiring roboticist.

To control the robot arms movements [jjshortcut] plans to use a standard Arduino. There are certainly plenty of servo motor shields available but he still decided to design his own. In addition to the standard motor power and servo connections, a header for an infrared receiver was added for potential future communication options.

Like any project, there were some hiccups along the way. First, several revisions of the gripper were necessary to get the correct tooth profile that resulted in smooth and tight movement. Also, while making the shield the spacing between banks of headers came out one header too close! On this first board [jjshortcut] just bent the pins so they would fit into the Arduino. You can’t let some minor snafu prevent forward momentum of a project!

[jjshortcut] has done the hard part; the design. He has made all his mechanical and electronic files available… so go and build one! Check out the video after the break.

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Ask Hackaday: Who Is Going To Build This Pneumatic Transmission Thing?

October 10, 2014 by Brian Benchoff 59 Comments

Disney research is doing what they do best, building really cool stuff for Disney and telling the rest of the world how cool they are. This time, it’s a very low friction fluid transmission device designed for animatronics.

From testing a few toy robotic arms, we can say without a doubt that servos and motors are not the way to go if you’re designing robots and animatronics that need lifelike motion. To fix this, a few researchers at Disney Pittsburgh have turned to pneumatics and hydraulics, where one joint is controlled by two sets of pistons. It’s extremely similar to the pneumatic LEGO, but more precise and much more lifelike.

The system uses a pair of cylinders on each joint of a robot. Disney is using a rolling diaphragm to seal the working fluid in its tubes and cylinders. This is an extremely low-friction device without any shakiness or jitters found with simple o-ring pneumatics and hydraulics.

The system is backdriveable, meaning one robotic arm can control another, and the other way around. Since we’re dealing with hydraulics, the cylinders (and robotic/animatronic devices) don’t need to be the same size; a small device could easily control a larger copy of itself, and vice versa.

The devices are fairly simple, with gears, toothed belts, and bits of plastic between them. The only unique part of these robots is the rolling diaphragm, and we have no idea where to source this. It looks like it would be great for some robotics or an Iron Man-esque mech suit, but being able to source the components will be a challenge.

You can check out the videos of these devices below, and if you have any idea on how to build your own, leave a note in the comments.

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The Triple Delta Robot Arm (and Leg)

October 9, 2014 by Brian Benchoff 17 Comments

delta By now you’d think we’ve seen just about every means of robotic actuator possible. We have Cartesian bots, Stewart platforms, SCARA bots, Delta bots, and even some exceedingly bizarre linkages from [Nicholas Seward]. We’re not done with odd robotic arms, it seems, and now we have Delta-ish robots that can move outside their minimum enclosed volume. They’re fresh from the workshop of [Aad van der Geest], and he’s calling them double and triple Deltas.

Previous Delta robots have used three universal joints to move the end effector up and down, and side to side. They’re extremely fast and are a great design for 3D printers and pick and place machines, but they do have a limitation: the tip of a single Delta can not move much further than the base of the robot.

By adding more parallelograms to a Delta, [Aad] greatly increases working volume of a his robots. One of the suggested uses for this style of bot is for palletizers, demonstrated in the video below by stacking Jenga blocks. There is another very interesting application: legs. There’s footage of a small, simple triple Delta scooting around the floor, supported by wire training wheels below. It makes a good cat toy, but we’d love to see a bipedal robot with this style of legs.

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Scrobby’s On Your Roof, Cleaning Your Solar Panels

October 8, 2014 by Kristina Panos 33 Comments

Solar panels are a great, sustainable addition to your home’s energy scheme. They’re bound to get dirty, but they can’t withstand harsh chemicals and still be effective. While there are companies that will come out and clean your installation a few times a year, the service is a recurring cost that adds up quickly. With Scrobby, his entry into The Hackaday Prize, [Stefan] sought to build a highly affordable and sustainable solution that, after installation, requires no dangerous trips back up to the roof.

Scrobby is solar-powered and cleans using rainwater. The user can set and alter the cleaning schedule over Bluetooth from their phone. [Stefan]’s prototype was built around a Teensy 3.0, but he will ultimately use custom boards based on the Freescale KL26. In addition to the Bluetooth module, there are six ultrasonic sensors, rain and temperature sensors, and motor-driven spools for tethered movement.

Make the jump to see Scrobby get his prototype bristles installed and show off his abilities in [Stefan]’s demo video. To register for updates, check out Scrobby’s website. If you hurry, you can donate to Scrobby’s Kickstarter campaign. The question is, who will clean Scrobby’s solar panels?

This project is an official entry to The Hackaday Prize that sadly didn’t make the quarterfinal selection. It’s still a great project, and worthy of a Hackaday post on its own.

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PrintBot prints talcum powder on your floor

PrintBot Prints On The Ground, Uses Talcum Powder

October 7, 2014 by Rich Bremer 27 Comments

Yes, this is a printing ‘bot but it’s not a 3D Printer. Even though it’s called Printbot, don’t get it confused with other products that may begin with ‘Print’ and end in ‘bot’. Printbot is half Roomba, half old inkjet print carriage drive and the remaining half is a small PC running Windows CE.

The whole point of this ‘bot is to draw/write/print things on the floor. No, not in ink, in talcum powder! The Roomba drives in one axis as the powder is systematically dropped in the ‘bots wake. It works one line at a time, similar to how a progressive scan TV displays an image on the screen. The PC on board the Printbot reads 8-bit gray scale images from a USB drive, re-samples the image and outputs the image one line at a time to an external microcontroller. The microcontroller is responsible for driving the Roomba forward as well as moving the hopper’s position and dispensing the powder in the correct place. Check out the small photo below. That black and white strip is not there for good looks. It is part of the encoder positioning system that is responsible for communicating the location of the hopper back to the microcontroller.

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