A touch screen Geiger counter without a Geiger tube


We’re assuming [Toumal] was desperately bored one day, because in the depths of the Internet he found some really cool components to build a solid state Geiger counter.

The Arduino and touchscreen are rather standard fare [Toumal] picked up on eBay for about $30. What really sets this project apart from all the other geiger counter builds we’ve seen is the solid state geiger counter [Toumal] used. This device uses a specially-made photodiode made by First Sensor to detect gamma emissions from 5 to 1000 keV.

[Toumal] put all the software for his Arduino touch screen radiation detector up on github. To be honest, we’re really impressed with the rad sensor [Toumal] used for this project, so if you ever decide to pick one of those up, he’s got your back with an Arduino library for it.

Potassium Chlorate from household products

To the upper right we have very pure potassium chlorate, so much so that it bursts into flames when mixed with sugar and catalyzed with some sulfuric acid. [Mr. Home Scientist] produced the KClO3 using household chemicals and some rudimentary equipment sourced on eBay.

The experiment started off with concentrated bleach containing 8.25% sodium hypochlorite. He needed sodium chlorate so a hot plate was used to boil the bleach until crystals started to form. A more efficient way to achieve this reaction would be using electrolysis (check out the HHO generator we saw recently for a homemade rig). The next step is to add potassium chloride, which is sourced from the grocery store as a sodium-free salt alternative. After mixing with the filtered remains of the bleach reaction the two are combined. There is no precipitate from this — an indication that not everything is as it should be. But an overnight stay in the refrigerator results in the potassium chlorate crystals seen above.

Fiery testing (seen below) lets him know the experiment worked. From here the product can be used for things like making solid rocket engines.

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Stopping a hackerspace from rusting away


The illutron hackerspace in Copenhagen makes their home on a barge sitting in port. Not only is this awesome, but the members of the hackerspace also worry about corrosion to their beloved fablab. In an effort to ally some fears about rust slowly eating through the hull, [Dzl] has rigged up a cathodic protection system for their hull, essentially preserving their barge at the expense of a few old steel rails.

Cathodic protection systems are able to protect the steel of a ship’s hull by offering up a sacrificial anode made of aluminum or zinc. This can be done by either attaching a sacrificial anode directly to the hull, or with a more complex system that connects both the cathode (the ship) and the anode (an engine block) to a DC power source.

[Dzl] is converting mains voltage down to 12 VDC, then further lowering the voltage with an Arduino-controlled buck converter. The control panel allows for adjustments in the voltage, as well as a nice uptime meter to make sure it’s running.

The results are fairly impressive; in the above pic, the right piece of steel was electrically connected to the barge’s hull, while the left piece was free to rust in the North Sea. That’s only two days worth of corrosion there.

Adult sized baking powder submarine


It really doesn’t matter what age you are, we’re sure you remember baking powder submarines. That’s because cereal manufacturers have been including them as prizes since the advent of injection molded plastic. Fill them with baking soda and take them in the bath with you. They gently dive and surface. The problem is that the cereal prizes were tiny. Now you can relive your childhood with an adult size version of your own making.

The submarine is basically a hunk of PVC with a conning tower to keep it upright and a chunk of hose into which the baking powder is placed. The idea is that the powdery acid and base that makes up the stuff reacts when hit with water. This gives off a bit of carbon dioxide, which makes the sub float to the surface until the bubble escapes and is replaced with water to again sink the ship. The difficult part is to find the right buoyancy (using wine bottle cork) so that the bubble is all it takes to oscillate between the surface and the watery depths.

Watch it go in the video after the break.

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On not getting metal fume fever with galvanized conduit


You can find galvanized steel pipes at Home Depots and construction sites all around the world. These relatively thin-walled steel pipes would make for great structural members if it weren’t for the fact they were covered in a protective layer of zinc. This layer of galvanization lends itself to crappy welds and some terrible fumes, but badass, TV personality, and hacker extraordinaire [Hackett] shows us how to strip the galvanization off these pipes with chemicals available at any hardware store.

Since the galvanization on these pipes covers the inside and the outside, grinding the small layer of zinc off these pipes is difficult at best. To be sure he gets all the zinc off this pipe, [Hackett] decided to chemically strip the pipes with a cup full of muriatic acid.

The process is simple enough – fill a cup with acid, dunk the ends of the pipes, and clean everything up with baking soda. A great way to turn scrap pipe into a usable material, make a cool paper mache volcano, and avoid ‘ol galvie flu

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HHO generator makes bubbles that go boom


Here’s [Phil] showing off the components he used to make an HHO generator. The device uses household items to generate hydrogen and oxygen from water using electrolysis.

He’s using a plastic Nesquik container as the vessel for his experiment. Inside is water doped with a bit of baking soda. The lid plays host to the majority of components. There are electrodes which stick through the lid of the container. To help boost the productivity of the generator these electrodes have several metal washers suspended between. It’s importnat to avoid a short circuit so they’re mounted with the plastic bolt from a toilet seat, and isolated using hot glue. A plastic tube used collects the gasses. You can tweak the ratio of what’s being collected by reversing the polarity of the battery.

It’s interesting to see soap bubbles lit on fire in the demo video. But there are more serious uses for this concept. People have been working on making it feasible to power cars from the hydrogen generated this way. We’ve also seen a plastic bottle rocket powered from an HHO generator, and there’s always the thought of building your own miniature dirigible.

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Hackit: Researchers wait 69-years to see tar move


This experiment was started at Trinity College Dublin way back in 1944. Its purpose is to prove that tar flows, and indeed it does let go of a drop about every ten years. The thing is that nobody has ever seen that happen, bringing up the “if a tree falls in the forest” scenario. The Nature article on this event even mentions another experiment whose last drop was missed because the camera monitoring it was offline. This time around they did get some footage of the (un)momentous event which you can see below.

So here’s the challenge for clever hackers: What’s the easiest rig you can think of that won’t just continuously film the experiment but can also ensure that you get the goods on tape when a drop does fall? We see all kinds of high-speed shutter triggers — here’s one of the latest. But we don’t remember seeing an extremely slow version of the same. Let us know your idea by leaving a comment.

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