Author: John Baichtal

208 Articles

Mindstorms Soccer Robot Inspired By Real Soccer Robot

August 12, 2017 by 3 Comments

[Bram], a 17-year-old robot fan from the Nertherlands, had an opportunity to watch a RoboCup soccer match played by autonomous robots, and was inspired to create his own Mindstorms version of the robot for a school project.

The robot he created is around 80 cm in diameter and is controlled by four daisy-chained EV bricks. There are nine large motors for controlling the wheels, two more large motors for grabbing the ball, and two medium motors for the ball-shooting mechanism. It uses a Pixycam for ball detection, and it can identify and move toward the ball so long as it’s within 2.5 m. A gyro sensor determines the robot’s rotational direction.

Our favorite detail of the robot is its giant omni wheels, constructed out of LEGO elements. Each one consists of sixteen Mindstorms-standard wheels arranged in a circle, with an offset double row of rollers to give the same angled effect as a Mechanum wheel’s rollers.

This story has even geekier roots. [Bram]’s robot was based off of the Turtle, a soccer-playing robot used to teach programming to college students. Like [Bram]’s creation, they also have omni wheels, and see with a Kinect as well as a 360-degree camera up top that uses a parabolic mirror to keep an eye on its surroundings. The Turtle uses a compass sensor to distinguish its goal from the opposing team’s goal.

We’ve covered soccer bots in the past, watch a soccer-playing robot score on a human goalie.
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Testing Distance Sensors

August 11, 2017 by 40 Comments

I’m working on a project involving the need to precisely move a tool based on the measured distance to an object. Okay, yeah, it’s a CNC mill. Anyway, I’d heard of time of fight sensors and decided to get one to test out, but also to be thorough I wanted to include other distance sensors as well: a Sharp digital distance sensor as well as a more sophisticated proximity/light sensor. I plugged them all into a breadboard and ran them through their paces, using a frame built from aluminum beams as a way of holding the target materials at a specific height.

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Explore Venus With A Strandbeest Rover

August 11, 2017 by 72 Comments

There’s a little problem with sending drones to Venus: it’s too hostile for electronics; the temperature averages 867 °F and the pressure at sea level is 90 atmospheres. The world duration record is 2 hours and 7 minutes, courtesy of Russia’s Venera 13 probe. To tackle the problem, JPL has created a concept for AREE, a mechanical robot designed to survive in that environment.

AREE consists of a Strandbeest configuration of multiple legs with a monster fan propelling it, and one can imagine it creeping over the Venusian landscape. While its propulsion system might be handled by the Strandbeest mechanism, it will still have to navigate and transmit data. We’re not sure how a mechanical radio wave might work–maybe like those propeller arrow-cutters that [Dain of the Iron Hills] busts out in movie version of the Hobbit? Chemical rockets that somehow don’t spontaneously ignite? Or maybe it can just “transfer all energy to life support” and AC the heck out of the radio.

We’re space nerds here at Hackaday–check out our piece about NASA employees’ talks at the 2016 Hackaday Superconference and our extracurricular tour of JPL.

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Retro DEF CON Badge Made From ’80s Parts

August 10, 2017 by 4 Comments

DEF CON 25’s theme was retro-tech, and [xres0nance] wasn’t kidding around in the retro badge he built for the convention. The badge was mostly built out of actual parts from the ’80s and ’90s, including the perfboard from Radio Shack—even the wire and solder. Of the whole project just the resistors and 555 were modern parts, and that’s only because [xres0nance] ran out of time.

[xres0nance]  delayed working on the badge until his flight, throwing the parts in a box, and staggering to the airport in the midst of a “three-alarm hangover”. He designed the badge on the plane, downloading datasheets over in-flight WiFi and sketching out circuits in his notebook.

The display is from an old cell phone, and it uses a matrix of diodes to spell out DEFCON without the help of a microcontroller. Each letter is powered by a transistor, with specific pins blocked out to selectively power the segments. He used a shift register timed by a 555 to trigger each letter in turn, with the display scrolling the resulting message.

We publish a lot of posts about con badges. See our DEF CON 2015 badge summary for a bunch of badges that we encountered at in Vegas.

CNC Mill Out Of A Building Set

August 10, 2017 by 19 Comments

I have some aluminum building-set parts on hand and just got a second rotary tool, so I thought I’d try my hand at making a light-duty CNC mill—maybe carve up some cheap pine or make circuit boards. This post explores some of the early decisions I’m facing as I begin the project.

Of primary importance is the basic format of the mill’s chassis. Gantry configuration or put everything in a box of girders? How will the axes move–belts or racks? How will the Z-axis work, the assembly that lowers the tool onto the material? Finally, once the chassis is complete, or perhaps beforehand, I’ll need to figure out how I intend to control the thing.

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Make A Tesla Coil Winding Rig With K’Nex

August 6, 2017 by 3 Comments

Instructables user [birdycrazy] built a winding rig from a PVC pipe and a bunch of K’Nex. He had recently started a Tesla coil project and needed an efficient way to wind the secondary coil. All of the designs for DIY winding rigs he found on the Internet required parts he didn’t have or simply cost a bunch of money. Then he realized he’d been building with K’nex a lot, and why not build a tool to help him?

He ended up investing only his K’nex elements and a length of 4” PVC pipe for the project. He used a K’nex 12V motor because it plugs in rather than requiring batteries. After the coil had been completely wound he set it to rotate the assembly over a period of several days while the varnish coating dried.

[birdycrazy] has several cool K’nex projects including a couple of automatic transmissions and a differential, all made with the toy. Also be sure to check out the K’nex whiteboard plotter, the Citadel monster K’nex castle, and the K’nex skeeball table we published in the past.