Napier’s bones are a set of labeled sticks which John Napier invented in the 1600s for solving multiplication problems. Nowadays, you may be more likely to use a calculator, but if you want to multiply the old fashioned way, make yourself a set of Napier’s bones. You can use paper, wood, or other materials, but this set is knit. It is one of many mathematical knitting projects by Pat Ashforth, Steve Plummer, and Ben Ashforth.
The image below shows how to arrange the bones if you wanted to multiply by 76495. For example, the bottom row, labeled 9 at left, allows you to read off 9 x 76495. The rightmost digit of the answer is the 5 seen in the triangle at right. Then read off the remaining digits by adding the two numbers in each parallelogram, carrying as necessary, e.g., 1+4 gives 5 as the next digit and 6+8=14 gives 4 as the following digit, with a carry of 1 into the digit after that. The result can be quickly read off as 688455.
More:
See all of George Hart’s Math Monday columns
After two amazing and inspiring iterations (2011 and 2010), we are excited to announce we are passing the Open Hardware Summit torch!
We had an amazing two years: we collectively created the first OSHW definition (which has been adopted by CERN), communally created a logo for our movement, grew into a community that supports each other on forums, mailing lists and sponsorships, launched the first Open Hardware Scholarship, turned a conference goodie bag into something you would wrestle over, and created a geek red carpet that would have the Oscar’s drooling!
It was inspiring serving such an impassioned community, and we will both continue to serve in our own ways. The Open Hardware Summit is a mission-driven conference. It’s non-profit, and a labour of love. Our aim is to continually involve more and more of the community. In that effort we are announcing Catarina Mota and Dustyn Roberts as the two new co-chairs for the 2012 Open Hardware Summit.
With Catarina’s expertise in Open Materials, and Dustyn’s work in open mechanisms and robotics, each will bring a unique new dimension to the term “Open Hardware” and together broaden the relevance and reach of our movement and summit.
Thank you all for the support, we cannot stress enough that this is your movement, and everyone here has helped make it happen. The support for the Summit, from helping hands to donations, made it possible. Please continue to support the movement as it goes forward.
I can’t think of two better people to continue making the Open Hardware Summit THE best event for open-source hardware makers. Congrats to Catarina and Dustyn!
Yoonjo Choi of ITP took an old typewriter and harnessed its power of nostalgia to flip through projections of old photographs that have sentimental value to her.
A typewriter already has an interface that makes you want to push the many buttons and turn the handle where paper is supposed to roll in or out. I wish to joint these points with flex or force sensors and have them connected to a monitor. On the monitor there will be a old photo displayed. However, you can only see the photo when you type into the typewriter at a certain rate. For example, if you type less than five letters within ten seconds you will only get a vague outline of the photo. If you type more than five and less than ten letters it gets a bit more crisp, and so forth.
The way the stills flip through quickly on the typewriter’s paper as she advances the typewriter has a particularly magical effect. The project draws attention to the photos in a way that a digital slideshow or picture frame cannot.
Join us Wednesday evening for the next episode of Make: Live, our streaming show and tell! This week it’s our Holiday Giveaway show. We’ll look at holiday projects like Matt’s internet-connected Christmas tree, meet Michael Colombo’s homemade Magnetotron instrument, and give away some serious holiday prizes from Digi-Key for live viewers in the chat:
Make: Live 22: Holiday Giveaway
Wednesday December 14, 9pm ET/6pm PT
Watch at makezine.com/live or on UStream
Please join us in the UStream chat or mark tweets with #makelive to interact live with the show.
Want to show us your project? Upload a video or photos and send a link to live@makezine.com.
We’re giving away amazing kits from our new Make: Ultimate Kit Guide EVERY DAY — thousands of dollars worth of merchandise, including MakerBots!
To celebrate the release of our latest publication, the Make: Ultimate Kit Guide 2012 (and its companion website), we’re giving away at least one of the cool kits reviewed in the issue each day during the holiday season.
Today’s giveaway is the Maker Shed’s minty fresh Mintronics Bundle – Mintduino and Survival Pack (a $44.98 value.) Here is the review from the guide:
The Mintronics Bundle from the Maker Shed is a great way to get started with Arduino and electronics. It includes a MintDuino — a mint tin containing all the components you need to build a full-featured Arduino-compatible microcontroller — plus the Mintronics Survival Pack, another tin containing over 60 über-handy components you can use for quick fixes or complete electronics projects. (To upload your programs onto the ATmega328P microprocessor, you’ll also need an FTDI programmer like the FTDI Friend.)
To be eligible for today’s giveaway, all you have to do is leave a comment below in this post. The entry period for today’s prize will be until 11:59pm PST tonight. We’ll choose one person at random, you’ll be notified by email, and you’ll have 48 hours to respond. The Winners List is kept on the Giveaway landing page. That’s it! No purchase necessary or anything else to do. Please leave only one comment per post. You can enter as many giveaways as you like until you win. This giveaway is for US residents only. You also must be 18 years old to enter (Kids: Ask your parents to enter). See the Kit-A-Day Giveaway landing page for full sweepstakes details and Official Rules.
Important Note: If you enter this drawing, when it’s over, please check the place where you registered to comment (eg. Facebook, Yahoo, Twitter). Some people are winning these kits and then not responding when we send them a message using the available means of contacting them. We want to make sure you get your giveaway!
Do you have someone on your Christmas list that wants to get into electronics but doesn’t know where to start? The Discover Electronics Kit V2 available in the Maker Shed is perfect for beginners or anyone wanting a refresher in electronics. The well written instructions and step-by-step online video course will take them from lighting an LED to making an Atari Punk Console while learning electrical theory and how to read schematics along the way. When the online course is finished the recipient will be able to upgrade the kit with additional components so it can grow right along with them. It’s a well packaged, well documented kit that’s educational, fun, and rewarding!
Hint Hint: You might want to check today’s Maker Shed Deal of the Day! Follow the Maker Shed on Twitter, or subscribe to our Deal of The Day RSS feed to keep up to date on the latest deal.
Weekend Projects reader Robert writes in with his version of the Treasure Finder, a homemade metal detector, including custom board mods and alternative wire coil material. I don’t know where Robert lives, but I hope it’s near lots of treasures, and he cuts us in on any hoards he finds!
I completed this project in about 4 days. I made things harder for myself by not bothering with an etched circuitboard, just wired up on perfboard. Worked first time though!
My capacitors on the coils are very temperature sensitive. If I touch them with my finger, the tone goes crazy. Not sure if this is because I fried them when soldering though. I was going to use a friends oscilloscope but when I wired things up, it just worked and I could fine tune with the brass locknut.
Der Exot is the resurrection of a project monochrom started as early as 1997: a mobile robot with a mounted camera that can be controlled via web interface. But that’s tricky. If too many people try to control the robot at the same time it is counter-productive. Der Exot would behave schizophrenically. It would move without plan, and wander aimlessly. Der Exot is the anti-crowd source robot. The users have to discuss and cooperate via a chat interface to communicate where they want to go, what corners they want to explore, what to crush.
(The robot was featured in the Robotville Festival at London’s Science Museum, but I’m not sure whether it’s still up and running.)
Cool story from the MAKE Flickr pool: Alex French designed and carefully machined a torsion-set engagement ring to propose to his longtime sweetheart, Colleen. He studied up, tooled up with a Sherline 4000A hobby lathe/mill/drill press combo, then turned, bored, and milled the ring before setting the stone, himself, all while working secretly in a spare bedroom in their shared home.
The ring started as a 2″ long piece of 1″ diameter rod of 6Al-4V Grade 5 ELI titanium. Ultimate tensile strength: 125,000 psi. Yield strengh: 115,000 psi. 6% Aluminum, 4% Vanadium, bio-compatible. ELI is “extra low interstitial”, less than 0.14% iron and
I turned to Machinery’s Handbook for structural analysis, based on looking at the tension setting as a single loop of a torsion spring…If I’m correct, 1 pound of force at the stone setting deforms the ring about 0.007 inches. The opening was milled to dimensions that creatae about 2 pounds of force on the ring. It would take about four pounds of force to open the ring enough for the stone to slide out radially, or less to slide out along the ring finger axis.
See the work-in-progress shots, and read the whole story, in Alex’s Flickr set.
This was an especially beautiful week in the MAKE Flickr pool, and my choices were harder than usual. Our featured image is one of Steve Lodefink’s beautiful pinewood derby cars, which Mark recently covered on Boing Boing. Then there’s a characteristically amazing Space Marine prop helmet made from folded paper by Shawn Thorsson, and a subdued-but-striking shot of a mortise and tenon on David Popdan’s recent Japanese workhorse build. And there was no way I could resist a working LED up the nose, which I fully expect will launch a worldwide fashion craze.
We’re giving away amazing kits from our new Make: Ultimate Kit Guide EVERY DAY — thousands of dollars worth of merchandise, including MakerBots!
To celebrate the release of our latest publication, the Make: Ultimate Kit Guide 2012 (and its companion website), we’re giving away at least one of the cool kits reviewed in the issue each day during the holiday season.
Today’s giveaway is a bundle of THREE of the awesome and popular Herbie the Mousebot kits (one red, one white, the one, a $120 value!). Here’s part of Ryan Pederson’s review from the Kit Guide.
I built this Mousebot with my son, who had just turned 10. At first, I had to show him how to solder and helped him align the sides (not too easy), but by the end, he was doing all of the work himself and enjoying the “toughness” of the assembly. This kit is simple, but it demands attention to detail. The fun directions include jokes for kids and adults. All in all, this is a great starter kit, but you’ll need a nice soldering iron.
To be eligible for today’s giveaway, all you have to do is leave a comment below in this post. The entry period for today’s prize will be until 11:59pm PST tonight. We’ll choose one person at random, you’ll be notified by email, and you’ll have 48 hours to respond. The Winners List is kept on the Giveaway landing page. That’s it! No purchase necessary or anything else to do. Please leave only one comment per post. You can enter as many giveaways as you like until you win. This giveaway is for US residents only. You also must be 18 years old to enter (Kids: Ask your parents to enter). See the Kit-A-Day Giveaway landing page for full sweepstakes details and Official Rules.
Important Note: If you enter this drawing, when it’s over, please check the place where you registered to comment (eg. Facebook, Yahoo, Twitter). Some people are winning these kits and then not responding when we send them a message using the available means of contacting them. We want to make sure you get your giveaway!
