Water Purification Uses Home-built Electrolysis Rig

September 28, 2012 by Mike Szczys 58 Comments

If you plan ahead a little bit you could have your own system of water purification to use in emergencies. Everyone needs clean drinking water and this gadget will let your produce your own purification drops quite easily.

The solution contains chlorine, which is created through electrolysis. The PVC cap seen near the bottom of the image has two electrodes sticking out of it. These are titanium plated mesh plates separated by a rubber ring. The cap has a small hole in it to keep the flow rate low and the fitting at the top acts as a funnel. When you pour in a salt water mixture it passes through the energized plates and a chemical reaction splits the sodium from the chlorine.

A twelve volt power source is necessary for this to work. But since the electrolytic process takes just a minute or two you could easily source the power from batteries charged with solar cells. Check out a full build walk through and demonstration video after the break.

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Hybrid Rocket Engine Uses Acrylic As Fuel

September 26, 2012 by Mike Szczys 33 Comments

We are fascinated by the hybrid rocket engine which [Ben Krasnow] built and tested in his shop. It is actually using a hollow cylinder of acrylic as the fuel, with gaseous oxygen as an oxidizer. We’re already quite familiar with solid rocket propellant, but this hybrid approach is much different.

When a rocket motor using solid propellant is lit it continues to burn until all of the fuel is consumed. That is not the case with this design. The acrylic is actually burning, but if the flow of oxygen is cut off it will go out and can be ignited later. This also opens up the possibility of adjusting thrust by regulating the pressure of the oxygen feed.

[Ben] milled the test rig in his shop. It’s a fat acrylic rod through which he bored a hole. There are two aluminum plates which complete either end of the chamber. The intake has a fitting for a valve which connects to the oxygen tank. There is a nozzle on the outflow end. Check out the video after the break to see a full description. You’ll also get a look at the toll the combustion heat takes on the rig.

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Dropping The Nitrogen Bomb In Science Class

September 20, 2012 by Mike Szczys 40 Comments

We took Geology in college. It was pretty cool learning about the hardness of different minerals. But there were no explosions involved. We’re not entirely sure what this class is, perhaps Chemistry, maybe Physics, but we want in. [Dr. Roy Lowry] wows the class with a bomb made of liquid nitrogen. The demonstration was part of his lecture at Plymouth University.

A small explosion is cool, but [Roy] knows how to add the wow factor. To make the bomb he filled a one liter plastic bottle about 1/3 of the way with liquid nitrogen. After tightly sealing the cap it was dropped in that garbage can which had a pool of warm water in it. Before quickly running away he and his assistant dumped a few garbage bags of ping-pong balls on top of it all. When the plastic bottle bursts under the pressure of the expanding gas it sends the garbage can about six feet into the air and floods the room with bouncing white balls. See the whole presentation for yourself in the clip after the break and don’t forget the sound so you can catch the oohs and aahs at the end.

Looks like a Hackerspace recruitment tool if we’ve ever seen one.

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DIY Flux Comes Straight From The Tree

September 19, 2012 by Mike Szczys 19 Comments

[Tom] needed more solder flux and instead of buying it he thought he’d try making his own. The thing is, he didn’t have any rosin on hand. But knowing its source let him acquire it for free. He took a sample of tree sap and turned it into his own solder flux.

We’ve seen a few different DIY flux recipes this year. The most recent guide suggests sourcing rosin from the hardware store because of the quality, or if that fails you’ll find some at the music store. [Tom] was lucky enough to find a large dollop leaking from a pine tree in his neighborhood. He let it sit overnight in a container along with some isopropyl alcohol. In the morning the sap had fully dissolved, so he ran it through a coffee filter to get rid of any debris. He keeps it in a small jar, applying it to his projects using cotton swabs. You can see his short soldering demo after the break.

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Rocket Propellant Manufactured From Old Newspaper

September 4, 2012 by Mike Szczys 43 Comments

It turns out that old newsprint can be a bit explosive; at least when it’s combined with the proper ingredients. [Markus Bindhammer] worked out a way to make solid rocket propellant from newspaper. Judging from the test footage after the break the home made engines work great!

There isn’t a long list of ingredients. In addition to newspaper you’ll need some potassium chlorate (KClO3) which serves as an oxidizer, white wood glue, and PVC pipe. The KClO3 is ground with a mortar and pestle, then run through a sieve before being combined with the wood glue. This combination is painted on the newspaper which is then rolled up with a glass rod at the center. This is allowed to harden before going into the PVC. The excess is trimmed and the whole thing is baked in a convection oven at 105 C for two hours.

If this process doesn’t suit you maybe cooking up a batch of sugar-based propellant is worth a try?

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