blog

8 Articles

Step The Halbach From My Magnets

May 4, 2018 by 5 Comments

[Klaus Halbach] gets his name attached to these clever arrangements of permanent magnets but the effect was discovered by [John C. Mallinson]. Mallinson array sounds good too, but what’s in a name? A Halbach array consists of permanent magnets with their poles rotated relative to each other. Depending on how they’re rotated, you can create some useful patterns in the overall magnetic field.

Over at the K&J Magnetics blog, they dig into the effects and power of these arrays in the linear form and the circular form. The Halbach effect may not be a common topic over dinner, but the arrays are appearing in some of the best tech including maglev trains, hoverboards (that don’t ride on rubber wheels), and the particle accelerators they were designed for.

Once aligned, these arrays sculpt a magnetic field. The field can be one-sided, neutralized at one point, and metal filings are used to demonstrate the shape of these fields in a quick video. In the video after the break, a powerful magnetic field is built but when a rare earth magnet is placed in the center, rather than blasting into one of the nearby magnets, it wobbles lazily.

Be careful when working with powerful magnets, they can pinch and crush, but go ahead and build your own levitating flyer or if you came for hoverboards, check out this hoverboard built with gardening tools.

 

Continue reading “Step The Halbach From My Magnets” →

Hackaday Prize Entry: Selfie Bot Let’s You Vlog Hands Free

July 8, 2016 by 23 Comments

[Sergey Mironov] sent in his SelfieBot project. His company, Endurance Robots, sells a commercial version of the bot, which leads us to believe that in a strange and maybe brilliant move he decided to just sell the prototype stage of the product development as a kit. Since he also gave away the firmware, STLs, BOM, and made a guide so anyone can build it, we’re not complaining.

The bot is simple enough. Nicely housed hobby servos in a 3D printed case take care of the pan and tilt of the camera. The base of the bot encloses the electronics, which are an Arduino nano, a Bluetooth module, and the support electronics for power and motor driving.

To perform the face tracking, the build assumes you have a second phone. This is silly, but isn’t so unreasonable. Most people who’ve had a smart phone for a few years have a spare one living in a drawer as back-up. One phone runs the face tracking software and points the bot, via Bluetooth, towards the user. The other phone records the video.

The bot is pretty jumpy in the example video, but this can be taken care of with better motors. For a proof-of-concept, it works. A video of it in action after the break.

Continue reading “Hackaday Prize Entry: Selfie Bot Let’s You Vlog Hands Free” →

Tindie Is Hiring A Writer

March 29, 2016 by 11 Comments

Tindie is the best place to find unique hardware. It’s hardware sold by it’s creators; you can’t just go out and buy it anywhere. The ideas for those creations, the design and engineering that went into them, and the background on both sellers making and buyers building is the story that makes Tindie special. It’s time to make that story a lot easier to discover.

Tindie has a Blog (which you should be following) and is now looking for its scribe to fill those pages. As a writer for Tindie you share the excitement of trying out the newest sensors, making things move, or even just the magic of that first simple blink. You will seek out amazing parts and people to highlight. In a few articles each week you’ll engage and energize the Tindie audience, highlight the cutting-edge new arrivals, and lead in brainstorming new builds.

Have I just described you? Then please apply to be a writer for Tindie. Email Tindie’s jobs line with the following:

  • Tell us about you. How did you get into building hardware? What are your educational, hobby, and professional backgrounds.
  • What direction do you think the Tindie blog should take?
  • Please choose one item offered by a seller on Tindie and write a sample article about it.

The position pays per article written. This is the first time Tindie is hiring a dedicated writer; it’s an opportunity for you to shape something new and amazing.

Hackaday Printing Press Upgrade

November 11, 2014 by 655 Comments

There comes a time when your movable type becomes so over-used that you no longer get a legible print off of the printing press. For months now we’ve been at work on a new site design that maintains the essence of Hackaday while ejecting the 10-year-old dregs of the site. With each small success we’ve actually ruined ourselves on viewing the old design. It is with great relief that we unveil a site design built specifically for Hackaday’s needs.

The most notable change is in the content of our landing page. For ten years, loading Hackaday.com resulted in the most recent blog posts. The blog concept is proven, but provides little opportunity to highlight quality original content and information about upcoming events. We have tried the use of “sticky” posts but honestly I find them somewhat annoying. The solution to this is not immediately apparent, but I feel we have found the most efficient solution to our complex set of needs..

We have a lot of community members who participate in Hackaday in numerous ways. Changes found in this design are driven by that fact. The landing page will, from this point forward, be a somewhat more persistent collection of notable content from the blog, our community site (hackaday.io), as well as news regarding live events, store features, contest highlights, and more. Those hard-core fans — a label I also assign to myself — will find the same reading experience as always on the new blog URL: hackaday.com/blog.

Aesthetically, we hope that all will agree the new design far supersedes the old. There was a lot to fix, and the work of the Hackaday crew who designed and implemented this new interface is truly amazing. I hope you will take the time to leave a positive comment about their work. As with any major transition, there will be some bumps in the road. Right now most of our sidebar widgets have not been migrated but that and any other problems will be fixed soon.

In this design we strived to highlight the title and image of each post to immediately convey the core concepts of the projects shown here. The author by-line and comment count remain core to the presentation of the articles, and our link style continues to be immediately apparent in the body of each article. I think we have far surpassed the readability of the comments section, in addition to the content itself. We knew we could rebuilt it… we have the technology… long live articles worth reading.

UPDATE: We are working very hard to fix all the parts that don’t look quite right. Thanks for your patience!

UPDATE 2: Infinite scrolling isn’t a feature, it’s a regression. On our test server all the blog listings were paginated just like always. When our host, WordPress VIP, pushed live the infinite scrolling manifested itself. We’ve filed a ticket with them and are hoping for a solution shortly.

UPDATE 3: Infinite scrolling has now been fixed and the blog layout now paginates. The mouse-over zoom effect has been removed. Slideshow speed has been adjusted and if you hover you mouse over a feature it will pause the scrolling.

There I Fixed It: A Blog About Hacking, Poorly.

October 6, 2009 by 24 Comments

austinb-ipodmuffler

Thereifixedit.com is a site filled with dubious innovations. Some of them are cool, some of them are clever, and most of them are terrifying. Anyone who has ever stood in front of a broken household appliance with a roll of duct tape, one screw driver with a bit chipped off the flat part, and determination will laugh themselves silly browsing through this site. Maybe some of the ghetto hacks we covered before should be in this list.

[Thanks for the link Dad]

WordPress 2.7 Upgrade In One Line

December 10, 2008 by 43 Comments

wordpress

BadPoetry WordPress 2.7 has just been released and features a complete interface overhaul. Hack a Day runs on WordPress MU hosted by WordPress.com, so we got this update last week. We run standard WordPress.org on all of our personal blogs though. We recommend it because it’s free, has a massive userbase, and if you host it yourself, you can do whatever you want with it.

To make the upgrade process as simple as possible (and for the sheer rush of ‘rm -rf’), we use a one line command.

$ curl http://wordpress.org/latest.zip -o "wp.zip" && unzip wp.zip && rm -rf ./wordpress/wp-content/ && cp -r ./wordpress/* ~/www/

curl downloads the latest version from wordpress. unzip unpacks all of the files into a directory called ‘wordpress’. rm -rf removes everything in the ‘wp-content’ directory. Otherwise, you will overwrite your images, themes, and plugins. cp -r copies everything to your http document root, overwriting the previous install.

Naturally, you should back up your current install and database beforehand. We tend to use the one-liner with reckless abandon. If you’re wondering about the terseness, it was designed to fit inside the 140 character limit of Twitter.

[Thanks, Chris Finke]

Hack A Day Is Always Hiring

October 3, 2008 by 14 Comments


We’re always looking for people to contribute posts daily and help expand the site. We’ve added a handful of contributors in the last couple months, which you can see in our new How-tos.

This is a paid, freelancing position that requires professionalism, consistency, and reliability. We want to hear from people that are passionate about software/hardware hacking and growing Hack a Day. To apply, send the following to jobs@hackaday.com

  • A short bio about yourself
  • 3 example daily posts written in the style of Hack a Day
  • 3 software or hardware how-tos you’d like to see. For examples of work we’ve done in the past, look here, here, here, and here.
  • A couple sentences on how you would improve the site either through features or content
  • Any additional reasons why you would make a good fit for Hack a Day

Do not send any attachments. Having your own blog you can show off is a definite plus.

[photo:fbz]