Year: 2017

200KV Capacitor Uses Cake Pan And Bowl

March 6, 2017 by 18 Comments

[PhysicsGirl] posts videos that would be good to use in a classroom or homeschool environment. She recently showed a 200KV capacitor made from a cake pan, a bowl, and some other common items (see video, below).

One of the most interesting things about the project was how they charged the capacitor. A PVC pipe and some common hardware made a wand that they’d charge by rubbing a foam sleeve up and down against the dome formed by a metal bowl. We might have used a cat, but there’s probably some law against that.

To discharge, they used the end of the wand and were able to get a 10 cm spark. Based on the dielectric constant for air, they estimated that equated to a 200KV charge. They also discharged it through someone’s finger, which didn’t seem like a great idea.

We’ve talked about [PhysicsGirl’s] videos before. Granted, a lot of this won’t help the experienced hacker, but if you work with kids, they are a great way to make physics interesting and approachable. We wish she’d spent more time on the actual construction (you’ll need to slow it down to see all the details), though. If you really want a capacitor for your high voltage mad science, you might find these more practical. We’ve seen many homemade capacitors for high voltage.

Continue reading “200KV Capacitor Uses Cake Pan And Bowl” →

Hull Pixel Bot, A Mobile Pixel

March 6, 2017 by 3 Comments

There are many designs for little two-wheeled robots available to download for constructors with an interest in simple robotics. You might even think there are so many that there could not possibly be room for another, but that has not deterred [Rob Miles]. He’s created HullPixelBot, a platform for a mobile pixel as well as for simple robotic experimentation.

So what makes HullPixelBot more than just Yet Another Arduino Powered Robot? For a start, it’s extremely well designed, and has a budget of less than £10 ($12.50). But the real reason to take notice lies in the comprehensive software, which packs in a language interpreter and MQTT endpoint for talking to an Azure IoT hub. This is much more than a simple Arduino bot on which you must craft your own sketches, instead, it is a platform for which the Arduino bot is merely the carrier.

The project has had quite a while to mature since its initial release, and now has the option of a single pixel or a ring of pixels. The eventual aim is to use swarms of networked HullPixelBots to create large autonomous moving pixel displays, containing more than a hundred individual pixels.

There is an early video of some PixelBots in action which we’ve placed below the break, but it serves more as eye candy than anything else. If you have a spare ten quid, download and print yourself a chassis, install Arduino and motors, and have a go yourself!

Continue reading “Hull Pixel Bot, A Mobile Pixel” →

Bulking Up A Lightweight Lathe With A Concrete Cart

March 5, 2017 by 21 Comments

When it comes to machine tools, a good rule of thumb is that heavier is better. A big South Bend lathe or Bridgeport mill might tip the scales at ludicrous weight, but all that mass goes to damping vibration and improving performance. So you’d figure a lathe made of soda cans could use all the help it could get; this cast concrete machine cart ought to fit the bill nicely

Perhaps you’ve caught our recent coverage of [Makercise]’s long and detailed vlog of his Gingery lathe build. If not, you might want to watch the 5-minute condensed video of the build, which shows the entire process from melting down scrap aluminum for castings to first chips. We love the build and the videos, but the lightweight lathe on that wooden bench never really worked for us, or for [Makercise], who notes that he was never able to crank the lathe up to full speed because of the vibrations. The cart attempts to fix that problem the old fashioned way – more mass.

There are a few “measure twice, cut once” moments in the video below, as well as a high pucker-factor slab lift that could have turned into a real disaster. We might have opted for a countertop-grade concrete mix that could be dyed and polished, but that would be just for looks. When all is said and done, the cart does exactly what it was built to do, and there’s even room on it for the shaper that’s next on the build list. We’re looking forward to that.

Continue reading “Bulking Up A Lightweight Lathe With A Concrete Cart” →

Solid State Battery From The Man Who Brought Us Lithium Ion

March 5, 2017 by 98 Comments

Who is [John Goodenough]? He’s 94, so he’s been around long enough that you ought to know him. He was one of the co-inventors of the lithium-ion battery. Think about how much that battery has changed electronics. [Goodenough] along with [Maria Helena Braga] may have come up with that battery’s successor: the solid state battery. There’s a paper available that is free, but requires registration. If you don’t want to register, you can read the news release from the University of Texas with no trouble.

Keywords used to describe the new battery are low-cost, noncombustible, long cycle life, high energy density, and fast charge and discharge rates. The pair is also claiming three times the energy density of a current lithium-ion battery. They also claim that the batteries recharge in minutes instead of hours. You can see a video from [Transport Evolved] that discusses the invention, below.

Continue reading “Solid State Battery From The Man Who Brought Us Lithium Ion” →

Hackaday Links: March 5, 2017

March 5, 2017 by 8 Comments

Statistically, more celebrities died in 2016 than would be expected. 2017 is turning out to be a little better, but we did recently lose the great [Bill Paxton]. Game over, man. Game over. A few years ago, [Benheck] built his own pinball machine. It’s Bill Paxton Pinball. A great build, and worth revisiting, just like another viewing of Aliens and Apollo 13.

Some of the most popular 3D-printable objects are [flowalistik]’s low-poly Pokemon series. They’re great models, even though he missed the most obvious Pokemon. Of [flowalistik]’s low-poly Pokemon models, the Bulbasaur is a crowd favorite. Because this model is constructed from flat planes joined at an angle, it’s possible to make a huge low-poly Bulbasaur on a laser cutter or a CNC router. Go home Bulbasaur, you’re drunk. We are eagerly awaiting details on how this grass and poison-type tank was made.

For the last few months, [Matthew Cremona] has been building a huge bandsaw mill in his backyard. It’s built for cutting logs into lumber, and this thing is massive. He’s been posting build log videos for the last few months, but this week he’s finally gotten to where we want him to be: he’s cutting gigantic logs. In the coming weeks, he’s going to be cutting a maple crotch that’s 60 inches (1.5 meters) across.

It’s still a bit early, but here are the details for the 2017 Open Hardware Summit. It’s October 5th in Downtown Denver. If you want to speak at OHS, here you go. If you want to sponsor OHS, here you go. Tickets are over on Eventbrite.

What happens when you give away a new Raspberry Pi Zero W to the fifth caller? This. In other news, Adafruit somehow acquired a real New York City payphone. I’ve heard they were replacing these with WiFi hotspots, which means there are a ton of payphones in a warehouse somewhere? Can anyone hook us up?

Mycelia + Sawdust = House?

March 5, 2017 by 59 Comments

Take a guess. What is the featured picture for this article? If you’re channeling your inner Google image recognition, you might say: “Best guess for this image: rock.” But, like Google, you’d be wrong. Instead, what you see are bricks made out of fungi obtained from tissues of mycelia.

By taking fungi obtained from tissues of mycelia and storing them in a jar filled with a growth medium (usually sawdust), MycoWorks is creating all sorts of materials with exciting properties. In just three to seven days, the fungi and sawdust mixture expands and forms into clumps of material, which are then used to create products like handbags, purses, bricks, you name it. According to co-founder Phil Ross, “production of this material is similar to making ravioli from scratch, and the final product is more resilient than concrete.”

The resulting materials are buoyant, self-extinguishing and stress dissipating. Moreover, the bricks are alive up until they are put in a kiln. This means bricks that are placed next to each other will grow together, effectively enabling a structure to be made out of just brick, no mortar. And, while they’re not 3D printed, houses made in this fashion have great potential. If these cool new materials have got you excited, and you want to get cozy with the fungus among us, why not go all out with an automated mushroom cultivator?

Video after the break.

Continue reading “Mycelia + Sawdust = House?” →

A Command-Line Stepper Library With All The Frills

March 5, 2017 by 30 Comments

When you already know exactly where and how you’d like your motor to behave, a code-compile-flash-run-debug cycle can work just fine. But if you want to play around with a stepper motor, there’s nothing like a live interface. [BrendaEM]’s RDL is a generic stepper motor driver environment that you can flash into an Arduino. RDL talks to your computer or cell phone over serial, and can command a stepper-driver IC to move the motor in three modes: rotary, divisions of a circle, and linear. (Hence the acronumical name.) Best of all, the entire system is interactive. Have a peek at the video below.

The software has quite a range of capabilities. Typing “?” gets you a list of commands, typing “@” tells you where the motor thinks it is, and “h” moves the motor back to its home position. Rotating by turns, degrees, or to a particular position are simple. It can also read from an analog joystick, which will control the rotation speed forward and backward in real time.

Division mode carves the pie up into a number of slices, and the motor spins to these particular locations. Twelve, or sixty, divisions gives you a clock, for instance. Acceleration and deceleration profiles are built in, but tweakable. You can change microstepping on the fly, and tweak many parameters of the drive, and then save all of the results to EEPROM. If you’re playing around with a new motor, and don’t know how quickly it can accelerate, or what speeds it’s capable of, nothing beats playing around with it interactively.

Continue reading “A Command-Line Stepper Library With All The Frills” →