Guinea Pig Methane Power!

October 18, 2015 by James Hobson 44 Comments

Half-way around the world, a couple in Peru is harnessing the power of guinea pig poop, to generate methane for their farm. We couldn’t make that up if we tried.

The couple are a pair of retired plant physiology professors who have taken to running a sustainable agriculture program in their very own villa called Casa Blanca. It’s a beautiful set of gardens complete with a lab for research. But the most curious thing is the thousand guinea pigs they raise. They have a special shed for them with small compartments separated by brickwork. The guinea pigs eat specialized plant waste, and in turn, produce an astonishing 3 tonnes of fecal matter per month.

They use around 200kg of the excrement to power their very own bio-digester which in turn produces 3 cubic meters of methane per day which they use for powering their villa. The rest of it is used for fertilizer that they sell to local farms.

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Washington DC Electrified With Raw Sewage

October 16, 2015 by James Hobson 25 Comments

Completely unrelated to the current political climate in the United States, did you know Washington D.C. is partially powered by a sewage plant? No, seriously.

That’s right, just this week the D.C. Water utility company has announced a bioenergy facility that makes use of resident’s waste water into producing methane gas which can than be burned to generate electricity — To the tune of 10 megawatts! The facility is saving the company an estimated $10 million a year in energy bills.

Simply put, the liquid is removed from the sewage water and the solids are refined into a type of fuel. Those solids are heated, mixed, and sterilized into a form that can be easily digested by a certain type of microbe, which then in turn produce methane for burning. For a more detailed explanation, check out the info-graphic from the Washington Post explaining the entire process.

And on a smaller scale, you could do something like this in your very own backyard.

Bell Clock Ain’t Your Grandfather’s

October 15, 2015 by James Hobson 13 Comments

Here’s a rather obscure clock that rings your bell. Literally. It’s a minimalist approach to the grandfather chime.

You’ll want to check out the video below to see the electronic base very nonchalantly striking the bottom of the handbell. It makes a nice ring and brings a smile to your face at how clever [Iam5volt] was with the fabrication. There aren’t any hints available on that video, but we searched around and found the original build details published about 5 years ago. The striker is a hacked mechanical relay!

The case of the relay is removed. A piece of stiff steel wire is affixed to swing along with the relay’s switch. This way, when current is applied to the proper inputs of the relay, the wire moves and a small screw head at the end strikes the bell. See what we mean by clever?

[Iam5volt] built this second revision of the clock in answer to our call for building clocks for social good. The display-free clock chimes the hour using a bell and only has a single button to reset time to HH:00:00

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Sandy Poems Drawn By A Robot Named Skryf

October 15, 2015 by James Hobson 14 Comments

If you were lucky at the 2015 World Maker Faire you may have stumbled upon strange writings of poetry on the ground — written in sand. While at first confusing, if you followed the poetry along you also caught a glimpse of Skryf, a draw bot by [Gijs van Bon].

The creator was asked to perform poems for a festival about transition and letting go. Naturally, building a robot to write poetry in sand was the downright obvious answer to the question.

I was asked to perform 40 poems during a 10 day festival, and the poems were about transition and letting go. And then I thought the obvious thing to do as an artist is to make a machine that writes those poems with sand. I started writing them, and when the third poem was written, the first one was completely gone, and it was such a beautiful thing.

The robot uses a laptop for input, which is connected to the bicycle carriage. One servo controls the left-to-right movement, and another releases the sand. Forward and back is controlled by the main drive train, which must have been fun to account for (they aren’t servos!)

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Mr. Trash Wheel Cleans Baltimore’s Harbor

October 14, 2015 by James Hobson 40 Comments

Quite frankly we’re rather surprised we haven’t heard of Mr. Trash Wheel before. It’s a community project by the Baltimore Waterfront’s Healthy Harbor program where they are trying to make the harbor both swimmable and fishable by 2020. One of the coolest projects that resonates with us is Mr. Trash Wheel — a waterwheel-powered-trash-collecting-conveyor-belt. Say that 10 times fast!

It was built in early 2014, and according to the latest data it has removed a whopping 160 tons of garbage from the waterway already. Floating buoy-nets direct the garbage floating on top of the water into a narrow passage where the conveyor belt powered by a waterwheel slowly picks up the trash, and then deposits it into a large dumpster on a barge.

In fact, it’s even saved a python from the water too!

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Homemade Soldering Station Does It Better

October 11, 2015 by James Hobson 34 Comments

Soldering stations are probably one of the most important tools in the hacker’s arsenal. Problem is — good ones are expensive, and sometimes the only difference between being okay at soldering versus being great at it, is the quality of the tool you’re using! Which is why [Albert] and [Matthias] decided to make their very own home-made Weller clone.

Since the most important part of the soldering iron is a good tip, they’re using a needle from Weller — they just need to be able to control it. They designed a 3D printed housing (source files here) for a small 1.8″ LCD screen, an Arduino Pro Mini and a MOSFET shield, and the 12v 8A power supply they chose. There are only two controls — on/off, and a potentiometer for adjusting the temperature.

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BOO! Teach Arduino Basics With This Fun Ghost

October 9, 2015 by James Hobson 9 Comments

Halloween is just around the corner, and the spooky themed tips are just starting to roll in. If you’re looking to one-up the basic store-bought decorations, and maybe teach your kid the basics of an Arduino while you’re at it — why not build a Peek-A-Boo Ghost!

Using an Arduino, two servo motors and an ultrasonic distance sensor it’s pretty easy to make this cute little ghost that covers its eyes when no one is around. They’re using cardboard for the ghost, but if you have access to a laser cutter at your hackerspace, you could make it a lot more robust using MDF or plywood.

When the ultrasonic distance sensor senses someone coming towards it, it’ll trigger the arms to move — though it’d be easy to add a small speaker element too and get some spooky music going as well!

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