35 MPH NERF Darts!

May 5, 2016 by Elliot Williams 15 Comments

Did you know the muzzle velocity of a NERF dart out of a toy gun? Neither did [MJHanagan] until he did all sorts of measurement. And now we all know: between 35 and 40 miles per hour (around 60 km/h).

First, he prototyped a single beam-break detector (shown above) and then expanded his build to two in order to get velocity info. A Propeller microcontroller took care of measuring the timing. Then came the gratuitous statistics. He took six different darts and shot them each 21 times, recording the timings. Dart #3 was the winner, but they all had similar average speeds. You’re not going to win the office NERF war by cherry-picking darts.

Anyway, [MJ] and his son had a good time testing them out, and he thinks this might make a good kids’ intro to science and statistics. We think that’s a great idea. You won’t be surprised that we’ve covered NERF chronographs before, but this implementation is definitely the scienciest!

Thanks [drudrudru] for the tip!

Automating RC Motor Efficiency Testing

April 4, 2016 by Brian Benchoff 9 Comments

Small brushless motors and LiPo batteries are one of the most impressive bits of technology popularized in recent years. Just a few years ago, RC aircraft were powered by either anemic brushed motors or gas. Quadcopters were rare. Now, with brushless motors, flying has never been easier, building electric longboards is simple, and electric bicycles are common.

Of course, if you’re going to make anything fly with a brushless motor, you’ll probably want to know the efficiency of your motor and prop setup. That’s the idea behind [Michal]’s Automated RC Motor Efficiency Tester, his entry to the 2016 Hackaday Prize.

[Michal]’s project is not a dynamometer, the device you should use if you’re measuring the torque or power of a motor. That’s not really what you want if you’re testing brushless motors and prop configurations, anyway; similarly sized props can have very different thrust profiles. Instead of building a dyno for a brushless motor, [Michal] is simply testing the thrust of a motor and prop combination.

The device is very similar to a device sold at Hobby King, and includes a motor mount, microcontroller and display, and a force sensor to graph the thrust generated by a motor and prop. Data can be saved to an SD card, and the device can be connected to a computer for automatic generation of pretty graphs.

Brushless motors are finding a lot of uses in everything from RC planes and quadcopters, to robotics and personal transportation devices. You usually don’t get much of a data sheet with these motors, so any device that can test these motors will be very useful.

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The Ultimate 1:1 BB-8 Build Guide

February 24, 2016 by Brandon Dunson 8 Comments

BB-8 is not only a cute little droid but also presents dandy of a challenge for hackers ’round the globe to try and recreate in the garage. Nonfunctional models are a dime a dozen and the novelty has long worn off the Sphero toy. This brings us to a legit full-scale BB-8, seen in action in the video after the break.

Lucky for us, [Ed Zarick] has written up a blog post that’s as impressive as the build itself. [Ed] has drawn some inspiration and shared knowledge from several online groups focused around recreating the BB-8. He also provides some thorough Solidworks assemblies that look painfully detailed.

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Most Beautiful Mini-Galaga-Pi Ever!

January 30, 2016 by Elliot Williams 21 Comments

The problem with click-bait titles, besides the fact that they make the reader feel cheated and maybe a little bit dirty for reading the article, is that they leave us with nothing to say when something is truly outstanding. But the video of [Tiburcio de la Carcova] building up a mini-Galaga cabinet (complete with actual tiny CRT screen from an old portable 5″ TV) is actually the best we’ve ever seen.

Plywood is laser-cut. Custom 3D printed parts are manufactured and assembled, including the joysticks and coin door. Aluminum panels are cut on a bandsaw and bent with a hand brake. Parts are super-glued. In short, it’s a complete, sped-up video of the cutting-edge of modern DIY fab. If that’s not enough reason to spend four minutes of your time, we don’t know what is.

[Tiburcio] has also made a mini Space Invaders, and is thinking of completing the top-20 of his youth. Pacman, Asteroids, and Missile Command are next. We can’t wait.

There are (ahem) a couple of Raspberry-Pi-powered video game emulators on Hackaday, so it’s a little awkward to pick one or two to link in. We’ll leave you with this build that also uses a small CRT monitor to good effect albeit in less-fancy clothing.

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“Hello Barbie” Not An IoT Nightmare After All

January 29, 2016 by Elliot Williams 25 Comments

Security researchers can be a grim crowd. Everything, when looked at closely enough, is insecure at some level, and this leads to a lot of pessimism in the industry. So it’s a bit of a shock to see a security report that’s filled with neither doom nor gloom.

We’d previously covered Somerset Recon’s initial teardown of “Hello Barbie” and were waiting with bated breath for the firmware dump and some real reverse engineering. Well, it happened and basically everything looks alright (PDF report). The Somerset folks desoldered the chip, dumped the flash ROM, and when the IDA-dust settled, Mattel used firmware that’s similar to what everyone else uses to run Amazon cloud service agents, but aimed at the “toytalk.com” network instead. In short, it uses a tested and basically sound firmware.

The web services that the creepy talking doll connected to were another story, and were full of holes that were being actively patched throughout Somerset’s investigation, but we were only really interested in the firmware anyway, and that looked OK. Not everything is horror stories in IoT security. Some stories do have a happy ending. Barbie can sleep well tonight.

Lego Technic Of The Past Eliminates Apple ][ With Arduino And Touchscreen

January 25, 2016 by Gerrit Coetzee 9 Comments

[JAC_101], the Director of Legal Evil Emeritus for LVL1 Hackerspace (don’t ask me, it’s their title system), was challenged to a hacking duel. It all started years ago. The person who is now president of LVL1, visited the space for the first time and brought with her a discarded Apple II controller for Lego bricks which had previously belonged to her father. Excited to test it, the space found that, unfortunately, LVL1’s Apple II wouldn’t boot. An argument ensued, probably some trash talking, and [JAC_101] left with the challenge: Could he build an Arduino interface for the Apple II Lego controller quicker than the hackerspace could fix its Apple II?”

Other things that belonged to people's fathers. — Other things that belonged to people’s fathers.

In the end, a concentrated force by one hacker over two years overcame the collective ADHD of many. He began by opening the interface to look inside, a completely unnecessary step since he found it was already thoroughly documented. Next he forgot about the project for a year. Then he remembered it, and built an interface for an Arduino Uno to hook to the controller and wrote a library for the interface. Realizing that sending serial commands was not in line with the original friendly intention of the device, he added a graphical display to the project; which allowed the user to control the panel with touch. In the end he won the challenge and LVL1 still doesn’t have a working Apple II. We assume some gloating occurred. Some videos of it in action after the break.

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The Toy Maker

January 22, 2016 by Anool Mahidharia 8 Comments

A large part of the world still educates their kids using a system that’s completely antiquated. Personal choices and interests don’t matter, and learning by rote is the norm. Government schooling is woefully inadequate and the teachers are just not equipped, or trained, to be able to impart useful education. [Arvind Gupta], a science educator, is trying to change this by teaching kids how to build toys. His YouTube channel on Toys for Science and Math Education has almost 100,000 subscribers and over 44 million views. It’s awesome.

[Arvind] graduated from one of the finest engineering schools in India, the Indian Institute of Technology in Kanpur, and joined the TATA conglomerate at their heavy-vehicles plant helping build trucks. It didn’t take him long to realize that he wasn’t cut out to be building trucks. So he took a year off and enrolled in a village science program which was working towards changing the education system. At the weekly village bazaar, he came across interesting pieces of arts and crafts that the villagers were selling. A piece of rubber tubing, used as the core of the valve in bicycle tubes, caught his eye. He bought a length and a couple of matchboxes, and created what he calls “matchstick Meccano”.

This was in the 1970’s. Since then, he has been travelling all over India getting children to learn by building fun toys. The toys he designs are made from commonly available raw material and can be easily built with minimum resources. These ingenious DIY toys and activities help make maths and science education fun and interesting for children at all levels of schooling. All of his work is shared in the spirit of open source and available via his website and YouTube channels. A large body of his work has been translated in to almost 20 languages and you are welcome to help add to that list by dubbing the videos.

Check out the INK Conference video below where he shares his passion for education and shows simple yet entertaining and well-designed toys built from trash and recycled materials.

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