Mechanisms: Gears

Even before the Industrial Revolution, gears of one kind or another have been put to work both for and against us. From ancient water wheels and windmills that ground grain and pounded flax, to the drive trains that power machines of war from siege engines to main battle tanks, gears have been essential parts of almost every mechanical device ever built. The next installment of our series on Mechanisms will take a brief look at gears and their applications.

Continue reading “Mechanisms: Gears”

We’re Hiring: Come Join Us!

The Hackaday writing crew goes to great lengths to cover all that is interesting to engineers and engineering enthusiasts. We find ourselves stretched a bit thin and it’s time to ask for help. Want to lend a hand while making some extra dough to plow back into your projects? These are work-from-home (or wherever you like) positions and we’re looking for awesome, motivated people to help guide Hackaday forward!

Contributors are hired as private contractors and paid for each article. You should have the technical expertise to understand the projects you write about, and a passion for the wide range of topics we feature. If you’re interested, please email our jobs line, and include:

  • Details about your background (education, employment, etc.) that make you a valuable addition to the team
  • Links to your blog/project posts/etc. which have been published on the Internet
  • One example post written in the voice of Hackaday. Include a banner image, at least 150 words, the link to the project, and any in-links to related and relevant Hackaday features

What are you waiting for? Ladies and Gentlemen, start your applications!

Get Together and Hack this Saturday at World Create Day!

Spend some time with the Hackaday Community in your area this weekend. There are more than 100 community organized meetups happening this Saturday for Hackaday World Create Day. Check the big map for one near you and click the “Join this event” button in the upper right of their events page to let them know you’re coming.

Sticker packs we’ve been sending out to local event organizers.

It’s always a blast to get together with friends new and old to work on a project you’ve been itching to build. Grab something from your work bench and have fun geeking out about it in the company of others. This is a great opportunity to get started on your 2018 Hackaday Prize entry. Brainstorm ideas for a project, get advice on your early build plans, and consider forming a team. Submit what you come up with this Saturday as your entry and improve upon it over the coming weeks.

Can you still sign up to host World Create Day? Of course! Fill out this form and we’ll get you set up right away.

If you simply can’t make it to a live event, you can still take part. Set aside time to hack and show off the stuff you’re working on through social media. We have a Tweetwall set up (great to put up on the projector during group meetups) which shares Tweets with the hashtag #WorldCreateDay.

Don’t Forget to Tell the Story of Your World Create Day

We’re on the lookout for cool stories and interesting hacks from your meetup so that we can feature them here on Hackaday. Last year we featured a number of meetups, like automated gardening in Cyprus and etching Robot PCBs in Osaka. There was also a roundup with baby guitar amps, power racing series, and Wacky Waving costume assembly. It’s truly a worldwide thing, here’s a roundup that spanned India, Austrailia, and the USA.

Take pictures, write about what goes one, and tag everything #WorldCreateDay so we have the info to report on your meetup!

A Tale of Two Phases and Tech Inertia

What kind of power service is in the United States? You probably answered 120-volt service. If you thought a little harder, you might remember that you have some 240-volt outlets and that some industrial service is three phase. There used to be DC service, but that was a long time ago. That’s about it, right? Turns out, no. There are a very few parts of the United States that have two-phase power. In addition, DC didn’t die as quickly as you might think. Why? It all boils down to history and technological inertia.

Split Phase Power by Charles Esson CC-BY-SA 3.0

You probably have quite a few 120-volt power jacks in sight. It is pretty hard to find a residence or commercial building these days that doesn’t have these outlets. If you have a heavy duty electric appliance, you may have a 240-volt plug, too. For home service, the power company supplies 240 V from a center tapped transformer. Your 120V outlets go from one side to the center, while your 240V outlets go to both sides. This is split phase service.

Industrial customers, on the other hand, are likely to get three-phase service. With three-phase, there are three wires, each carrying the line voltage but out of phase with each other. This allows smaller conductors to carry more power and simplifies motor designs. So why are there still a few pockets of two-phase?

Continue reading “A Tale of Two Phases and Tech Inertia”

Friday Hack Chat: Everything Raspberry Pi

The Raspberry Pi is six years old now, and in that time it’s become the most popular single board computer. Over these last few years, the Pi has improved from a relatively anemic board based on a smartphone SoC to a surprisingly fast board that’s loaded up with some of the best software and the best community support we’ve ever seen. There’s an awful lot you can do with a Pi, and the continued support of the Raspberry Pi Foundation has enabled millions of people to get their hands on a cheap computer that runs Linux. It’s great.

Now it’s your turn to ask the engineers behind this tiny little computer what’s going on in the world of Pi. We’re having a Hack Chat this Friday, and you’re invited.

Our guest for this week’s Hack Chat will be [Roger Thornton], principal hardware engineer for the Raspberry Pi, where he oversees design, test, compliance, and production for Raspberry Pi products. Previously, [Roger]’s work for Broadcom included being part of the team that characterized and tested numerous SoCs including the BCM2835/6/7 found in various Pis. He also has experience in the smart home and IoT fields from working in a consultancy where be helped bring chips to market.

[Roger]’s most recent work was announced today; the Raspberry Pi 3 Model B+ is the latest in a long line of Pis, and while it’s not the octocore ARM monster with SATA and PCIe and Gigabit networking and 4G that the power-hungry have been clamoring for, it is more capable than its predecessor and still only costs less than forty bucks.

This is also the second time [Roger] has been a guest on our Hack Chats. You can check out the transcript of the 2017 chat here.

During this chat, we’re going to be discussing the future of Raspberry Pi products, Pi events around the world, and a question on the minds of many: where you can buy Pi Zeros in quantity. You are, of course, encouraged to add your own questions to the Hack Chat. You can do that by leaving the questions as a comment on this Hack Chat’s event page.


Our Hack Chats are live community events on the Hack Chat group messaging. This week it’s going down at the usual time, on noon, Pacific, Friday, March 16th  Want to know what time this is happening in your neck of the woods? Have a countdown timer!

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.

Stephanie Kwolek: Saving Lives with Kevlar

Almost a really bad day in the woods.

Like most accidents, it happened in an instant that seemed to last an eternity. I had been felling trees for firewood all afternoon, and in the waning light of a cold November day, I was getting ready to call it quits. There was one tiny little white pine sapling left that I wanted to clear, no thicker than my arm. I walked over with my Stihl MS-290, with a brand new, razor sharp chain. I didn’t take this sapling seriously — my first mistake — and cut right through it rather than notching it. The tree fell safely, and I stood up with both hands on the saw. Somehow I lost my footing, swiveled, and struck my left knee hard with the still-running chainsaw. It kicked my knee back so hard that it knocked me to the ground.

In another world, that would likely have a been a fatal injury — I was alone, far from the house, and I would have had mere minutes to improvise a tourniquet before bleeding out. But as fate would have it, I was protected by my chainsaw chaps, full of long strands of the synthetic fiber Kevlar.

The chain ripped open the chaps, pulled the ultrastrong fibers out, and instantly jammed the saw. I walked away feeling very stupid, very lucky, and with not a scratch on me. Although I didn’t realize it at the time,  I owed my life to Stephanie Kwolek.

Continue reading “Stephanie Kwolek: Saving Lives with Kevlar”

Lost In Space: How Materials Degrade In Space

Hackaday readers are well aware of the problems caused by materials left exposed to the environment over time, whether that be oxidized contact pads on circuit boards or plastics made brittle from long exposure to the sun’s UV rays.

Now consider the perils faced by materials on the International Space Station (ISS), launched beginning in 1998 and planned to be used until 2028. That’s a total of 30 years in an environment of unfiltered sunlight, extreme temperatures, micrometeoroids, and even problems caused by oxygen. What about the exposure faced by the newly launched Tesla Roadster, an entirely non-space hardened vehicle on a million-year orbit around the sun? How are the materials which make up the ISS and the Roadster affected by the harsh space environment?

Fortunately, we’ve been doing experiments since the 1970s in Earth orbit which can give us answers. The missions and experiments themselves are as interesting as the results so let’s look at how we put materials into orbit to be tested against the rigors of space.

Continue reading “Lost In Space: How Materials Degrade In Space”