Student Built Robot Chassis Has Something You Can Learn From

October 5, 2011 by Mike Szczys 27 Comments

This is a four-wheeled robot chassis built by high school students over the summer. They were participating in workshops put on by xbot robotics in Seattle, Washington. The goal is to get them participating in events like FIRST Robotics and LEGO league, and eventually into science related careers.

At first glance we thought: oh, that’s a nice chassis build… on to the next tip. But then the difference in front and rear wheel types caught our eye. The problem with four-wheeled designs is that you need differential steering to overcome the skidding issue when turning. This usually means two independently powered rear wheels and one unpowered front wheel that can swivel. One way to overcome this is to use three omniwheels, each with their own motor. And more recently we have seen four-wheelers that use mechanum wheels to get around the issue… but that takes four motors.

The design seen above uses just two motors, each with a chain to drive both wheels on one side. The rear wheels have rubber grippers which give them great traction. The front wheels are omni-wheels which allow them to move side to side easily during turns while aiding in forward progress when not turning. This gives the robot enough grip to push object around, like you can see in the video after the break.

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Robotic Arm Follows The Movements Of Your Own Limbs

October 2, 2011 by Mike Szczys 3 Comments

[Alejandro] and his friends recently finished a first prototype of scratch-built robotic arm. They’ve got some nice electronics bench equipment for use with a project like this, but for the actual fabrication work it’s off to the kitchen.

As you can see in the video after the break, they’re using PVC as the stock material in this build. Flat sheets are produced by slitting a PVC pipe down the middle, warming it in oven until soft, then compressing it between two floor tiles with a big jug of water used as a weight for the makeshift press. Mounting holes for the servo motors that make up the joints are drilled with a hand drill, and the assembly was affixed to an old CD as a base.

Once assembled they wired it to the control circuitry and build a set of sensors that you wear on your arm. Now your elbow, wrist, and pointer finger are in control of the servos. A demonstration of this functionality starts around two minutes into the video.

We’ve seen other examples of robot arms built without the use of machine tools. This arm made out of ShapeLock plastic is one of the most interesting examples.

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Page-turning Book Scanner Roundup

October 2, 2011 by Brian Benchoff 9 Comments

[Daniel] at diybookscanner.org posted a roundup of the best automatic book scanner builds to date. A lot of the comments on our last coverage of book scanners were summed up by [Spork] with, “No automatic page turning = no use.” Turning a page in a book with a robot is really hard, though, and these builds do a really amazing job at automating very tedious work.

First up is [jck57]’s servo actuated auto scanner. From the video, this build is very good and we caught it skipping only one page. Check out the video in action and the overview.

Next up is the Berlin Hackerspace c-base’s vacuum box scanner. The video shows a large diamond-shaped box with a vacuum cleaner hose attached to the top. The box is pressed down into the binding of the book where the vacuum picks up the next page. The build is a manual version of this very expensive machine, but does have the bonus of not poking a centuries-old book with robotic manipulators.

[dtic] was one of the first people to look into automatic page turning. His prototype (video here) uses servos, but has a very simple construction. The downside is that the book can only scan one side of the book at a time; to get other side, the user would have to turn the book upside down and scan it again.

Project Gado was an unsuccessful Kickstarter campaign whose goal was to develop a scanner to archive photos at Johns Hopkins University. The build used a vacuum-powered suction cup to lift pages onto a flatbed scanner. It’s a lot slower than some of the other builds, but we think there would be less of a risk of skipping a page.

As for processing the images captured by a digital camera, [Steve]’s book scan wizard handles a lot of the necessary post processing tasks. Converting everything to a PDF, changing the DPI, and putting all the pages in order can be done with [Steve]’s app. Download here.

Turning a page of a book is a very hard problem – books are designed for hands, not grippers. If you’ve got a book scanner build you’d like to show off, send it in on the tip line. We’ll be sure to put it up.

New BigDog Video Doesn’t Fail To Impress

September 30, 2011 by Mike Szczys 40 Comments

Those following the evolution of quadrupedal assist robots will recognize the specimen seen above as a relative of BigDog. This is AlphaDog, one of the latest prototypes in Boston Dynamics’ Legged Squadron Support Systems program. It’s designed to carry 400 pounds of payload, which explains the disc weights seen on either side of the torso. Like its diminutive sibling, LittleDog, it’s able to take on all kinds of terrain. Here it’s being tested with boxes full of rocks.

The robot is capable of picking itself up and getting under way again without intervention. The first video after the break shows test footage where the robot starts nearly upside-down and has no trouble righting itself again. When we looked in on a biped version back in 2009 we also linked to the BigDog prototype which showed developers trying to tip it over mid stride. This version has the same balance resiliency.

Also embedded after the break is a video showing the evolution of the design over about seven years of development.

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Robotic Disco Floor Is A Mobile Party

September 18, 2011 by Brian Benchoff 16 Comments

[Chris Williamson] designed the Rave Rover, a mobile disco floor with integrated stripper pole for this year’s DragonCon.

[Chris] started building combat robots back in 2000 for Battlebots and Robot Wars and cofounded the South Eastern Combat Robot league. He’s a lover and not a fighter, so for the DragonCon robotics track [Chris] built his mobile dance party. He put up an Instructable of his build and some of the features are really clever. Whenever the dance floor is being ‘used’, pneumatic cylinders lower the disco floor so it rests directly on the ground. A good idea, especially considering what we imagine happens on the Rave Rover.

For the light-up disco floor, [Chris] cut black ABS sheets on a CNC router and installed RGB LED modules controlled by an Arduino. The floor can display low-res animations, but random patterns look just a cool.

The Rave Rover was designed and built over a one month span to get ready in time for DragonCon. The build was a little hurried but the quality is still there. Check out video of the Rave Rover at DragonCon after the break.

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Mechatron, Industrial Looking Security Bot

September 18, 2011 by Caleb Kraft 27 Comments

This little beast is named Mechatron. Built by a father/daughter team called Beatty Robotics, the goal was to build something “retro-futuristic, tough, and industrial”. We think they definitely pulled off some of their goals here. Weighing in at nearly 50 pounds, Mechatron is still very agile, as you can see in the video below. He can fire his gun, which uses brass or plastic bullets, at a rate of nearly 1,000 rounds per minute while traveling in any direction thanks to the use of the mechanum wheels. 8 range finding sonar sensors, a laser and a turret that rotates 360 degrees will make sure you don’t elude Mechatron’s watchful eye… and shooting. While we were initially debating how they could make the Mechatron look more reto-futuristic, we all agreed that the lights in the video helped a lot. Maybe a curvy body piece could help too, depending on what era they were hoping to achieve.

[via buildlounge]

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