Look how fast these tiny Japanese sumo robots move

These little remote control vehicles are designed to push each other out of a small circle. They dart so fast that it's hard to keep up.

[via] Read the rest

Is this the world's oldest, simplest chair design?

It's been called a Camping Chair, a Bog Chair, an X-Chair, a Stargazer Chair, a Viking Chair, an African Chair, but "no one can agree on where the design first came from or what it ought be called," says Rain Noe. In his article for Core 77 he looks at the many variations of this simple flat pack chair.

Steve Ramsey shows how to make one: Read the rest

Make: a gorgeous, dramatic Internet Kill Switch

Want to be really sure that your Internet of Things gadgets and laptops aren't being remotely controlled by malware? Read the rest

Make: an Aeropress/water bottle cold-brew dripper

The cheapest and easiest way I know of to make cold brew coffee is with an almond-milk bag and a water jug, but if you favor the drip method over the steeping method, you can spare yourself the expense of a fancy Kyoto dripper and just use a disposable 500ml water bottle with a pinprick in its lid, suspended over an Aeropress. Read the rest

The Commute Deck: a homebrew Unix terminal for tight places

Kerry Scharfglass designed his "Commute Deck" as a laptop alternative for his morning commute: it combines a mechanical keyboard (running the TMK open keyboard firmware), a 7", 720p display from Adafruit, a long-life USB battery, and a Raspberry Pi 2 with USB, wifi and Bluetooth dongles, and a little USB hub, all mounted on a laser-cut 1/4" plywood chassis. Read the rest

"Purposeful objects that solve their own problems"

Dan Grayber's Cavity Mechanism series of sculptures are a hymn to "purposeful objects that solve their own problems," in which gravity acts upon systems of pulleys and scaffolds and wires to suspend weighty rocks in motionless perfection under glass domes. Read the rest

Cool hand-cranked laser show made from 3D printed parts

Evan built this nifty mechanical laser show on his 3D printer. The gizmo has two rotating cams that tilt a laser pointer up and down and from side to side in such a way that it draws different 3D shapes. In this video he explains the math behind it. You can download the model at Thingiverse

. Read the rest

How astrophysicist and Queen musician Brian May made his own guitar

Brian May, the lead guitarist and composer for Queen, is a multitalented guy. A Guitar World readers poll ranked him as the 2nd greatest guitarist of all time. He also has a PhD in astrophysics from Imperial College London was on the science team for NASA's New Horizons Pluto mission. He also made his own guitar with his father in the 1960s, which he called The Red Special. Hackaday has the build notes.

Every part of the Red Special was a process of trial and error. This is the true hacker spirit behind the guitar. Most trials didn’t work the first time, but Brian and Harold iterated until they reached their goals. An example of this is the pickups. Brian’s experimentation with pickups started with his Egmond guitar. He bought some Eclipse Magnetics button magnets from the local hardware store. These formed the core of the pickup. Harold then helped him build a coil winding machine, which allowed Brian to manually wind thousands of turns of fine copper wire around the pickups. It even had a wind counter built from a bicycle odometer.

Brian didn’t have an amplifier yet, so he plugged into the family’s radio. The pickups worked! They were very bright sounding, but had one flaw. When bending notes, Brian found there would be an odd sound as the string moved across the pickup. He attributed it to the North-South alignment of the disk magnet poles. Cutting the magnets was beyond the tools he had, and custom magnets were out of the budget.

Read the rest

Using centrifuge tubes to organize hardware

I bought a 50-pack of plastic centrifuge tubes for $14 on Amazon a couple of years ago. I was planning to use them to do geocaching with my daughter but we both lost interest. I left the tubes in a bag in the garage.

A couple of weeks ago I needed a screw to fix something. I have a plastic bin filled with loose hardware - nuts, nails, screws, picture hangers, wire nuts, and so on. When I reached in, I poked my finger with a thumbtack. It wasn't the first time that a sharp thing in the box had poked me, so I decided to sort the stuff into separate containers. As I thought about what kind of containers I should use, I remembered the centrifuge tubes. I used those.

I could have just kept the tubes in the same plastic bin that I'd used to hold the loose hardware, but since I have a new Original Prusa I3 MK2S 3D printer (which is amazing), I went ahead and made a wall-mountable tube holder. I used Tinkercad to design it. Here's the model.

I used double sided foam tape to mount the tube holder on the wall. I'll need to print out 10 of these to hold all 50 tubes. Read the rest

This doorlock from 1680 has lots of cool security features

This brass-and-steel "detector" doorlock, on display at Holland's Rijksmuseum, was made in 1680 or so. It has lots of clever features. To open and close the latch, you have to fiddle with the man's hat. The keyhole is hidden under the man's leg. It has a dial counter that lets you know how many times it has been unlocked, so the owner can tell if someone else opened it. When the lock has been opened 100 times as indicated on the dial, the main bolt can be locked, but not released until a tiny button on the man's chest is pressed, which resets the counter.

The inscription on the lock reads: "If I had the gift of tongue I would declare and do no wrong who you are that come by stealth to impair my master's wealth."

I hope they share the Arduino code for this.

[via] Read the rest

My card trick book is on sale for 99 cents

I became interested in magic when I was a young teenager, then dropped out for one reason or another. About five years ago I started getting interested again, this time in card magic (as opposed to stage magic). I had fun making doctored cards to use in my tricks, so in 2015 I wrote and illustrated a self-published ebook called Trick Decks: How to Hack Playing Cards for Astounding Magic. The sales exceeded my expectations, and it was at the top of the "magic" chart in Amazon for a quite a while.

Occasionally I reduce to price of the book. For the next few days, I've dropped the price of the ebook from $2.99 to 99 cents. It will go to $1.99, then back to $2.99.

Trick Decks will show you how to easily make different kinds of trick card decks to perform stunning magic tricks. You can make the decks from ordinary playing cards and easy-to-find tools and materials. No special skills are required and these cards are fun to make.

In this ebook you will learn The best way to mark cards How to make a stripper deck that lets you pull selected cards from the middle of the deck Two ways to make one of the greatest trick decks of all time: The Invisible Deck How to make the Brainwave Deck: A spectator’s thought-of card is the only one face up in the deck and with a different colored back than the other cards Nightmare Card: A card chosen by the spectator vanishes and reappears in your pocket Find out more about the ebook at Trick Decks website. Read the rest

Circuit Playground: explaining LEDs with cool puppets

Nick from Adafruit writes, "The latest installment of Circuit Playground is here: the letter L. Learn about how an LED works with Adabot and the Circuit Playground components." Read the rest

How to make a coin-operated gumball machine out of cardboard

Using cardboard, hot-glue, popsicle sticks, a pencil, and rubber bands, this guy makes a working coin-operated gumball machine. Good work!

[via] Read the rest

Guy makes a solid bronze axe, includes video where the axe falls and slices his legs open

This is an interesting 13 minute video about making a mold from a regural axe and casting a new axe in bronze. Around 10:30 into the video, the axe falls and slices the guy's leg open. For some reason, the guy doesn't mention this at all in the YouTube description, so it comes as a surprise.

And now I want an angle grinder. Read the rest

Arduino clone starter kit for $14

For $14, this is a really good starter kit for getting to know the Arduino electronics protyping platform. It has an Arduino Uno clone, a bunch of resistors, a capacitor, a photo resistor, a capacitor, pushbuttons, jumper wires, a speaker, a solderless breadboard, and a shift register integrated circuit (handy when you need more output pins than the Arduino supplies - see this tutorial). Read the rest

Maker Update: Hakko FX-901 cordless soldering iron

This week in Maker Update, Donald Bell presents a zoetrope combined with a fidget spinner, an SLS printer from Formlabs, a Raspberry Pi weather chamber, component carnage, and a tiny OLED Pi screen. Our featured Cool Tool is the Hakko FX-901 cordless soldering iron. Read the full review on Cool Tools. Read the rest

37 different sensor and effectors for Arduino $24

My daughter and I have set up a small maker space in our house and we are stocking it with components. Our latest acquisition: this 37-piece Arduino sensor and effector kit. It's a great deal at $24.

Here's what's inside:

Joystick Module

Relay Module

Rotary Encoder Module

DS-3231 RTC Module

Ultrasonic Sensor Module

HC-SR501 PIR sensor Module

Flame Sensor Module

Linear Hall Module

Metal Touch Module

Digital Temperature Module

Big Sound Module

Small Sound Module

RGB LED Module

SMD RGB Module

Two-tone Color Module

7 Color Flash Module

Laser Emit Module

Shack Module

IR Receiver Module

IR Emission Module

Tilt Switch Module

Button Module

Active Buzzer Module

Passive Buzzer Module

18B20 temp Module

Photo-resistor Module

Temperature and Humidity Module

GY-521 Module

Photo-interrupter Module

Tap Module

Membrane Switch Module

Avoidance Module

Tracking Module

Magnetic Spring Module

Water Lever Sensor

Power Supply Module

LCD1602 Module (with pin header) Read the rest

More posts