fog

9 Articles

A Song Of Fog And Fire – Taking A Look Inside A Rubens’ Tube

August 12, 2020 by 2 Comments

The dark winter months are still a bit ahead of us, but with night returning even to the northernmost places, it might be a good time to get your next mood lighting project started. Despite the ubiquitousness of LED strips, cave-time nostalgia makes it hard to beat the coziness of an actual flame here — well, assuming it’s a controlled flame. While modern LED candles do a decent enough job to fool you from a distance, there’s one apparatus they’ll have a hard time to replicate though: the Rubens’ tube. Tired of their usual straight pipe construct, [RyanMake] added some twists and turns to the concept and created a flexible Ruben’s tube made from semi-rigid aluminum ducts.

If you’re not familiar with the Rubens’ tube, it’s a combination of science, fun, and danger to visualize standing waves with fire by attaching a loudspeaker to a pipe with equally spaced holes that’s filled with flammable gas, and light it up. As the resulting visual effect depends on the audio signal’s wavelength, and by that the length of the tube itself, [RyanMake]’s flexible duct approach adds some variety to the usual fixed-length pipe versions of it. But that’s not all he did. After seeing the flames in person, he got curious about what’s actually going on inside that tube and decided to build another one, this time using a clear plastic tube and a fog machine. While the fog escapes the tube rather unimpressively (and could hardly compete with fire anyway), it gives a nice insight of what’s going on inside those tubes. See for yourself in the videos after the break.

Of course, no experiment is truly conducted without failure, and after seeing his first tube go up in flames several times, you should probably hold on to building one as decorative item for indoors. On the other hand, if shooting fire is what you’re looking for, you might be interested in this vortex cannon. And for some more twists on a standard Rubens’ tube, check out the two-dimensional Pyro Board.

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This Dry-Ice Powered Fog Machine Is Perfect For Halloween

October 14, 2019 by 19 Comments

The leaves are turning brown, and the spookier season is upon us. If you’re currently working up plans for a top-notch Halloween party, you would do well to consider building a fog machine like this unit from [DIY Machines]!

This fog machine is based around dry ice, so you’ll need to source that from an external supplier. The machine consists of a closed container filled with hot water, inside which is a movable bucket filled with dry ice. By lowering the dry ice into the water, fog is produced.

An Arduino is used to control the bucket, allowing the amount of fog produced to be controlled with a smartphone app. There are also controllable LEDs built in to give the fog a suitably eerie glow. The build relies on a series of 3D printed parts for the mechanism, and features several different nozzle designs for achieving different effects, such as a rising geyser or a thick low-lying fog.

The basic concepts are simple and it’s a build anyone could knock out in a weekend with a 3D printer and an Amazon account. It’s a great way to add to the ambience of Halloween, but of course, that’s not all fog can do. Video after the break.

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Extracting Water From Fog

June 13, 2018 by 53 Comments

Most of us take it for granted that water is as close as your kitchen tap. But that’s not true everywhere. Two scientists at MIT have a new method for harvesting water from fog, especially fog released from cooling towers such as those found from power plants. It turns out, harvesting water from fog isn’t a new idea. You typically insert a mesh into the air and collect water droplets from the fog. The problem is with a typical diameter of 10 microns, the water droplets mostly miss the mesh, meaning they typically extract no more than 2% of the water content in the air.

The team found two reasons for the low efficiency. Water clogs the mesh openings which can be somewhat mitigated by using coated meshes that shed water quickly. Even in the lab that only increases the yield to about 10%. The bigger problem, though, is basically only some of the droplets hit the mesh, and even those that do may not stick because of drag. Fine meshes can help but are harder to make and have low structural integrity. Their solution? Inject ions into the fog to charge the water droplets and impart the opposite charge on the mesh.

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Battery Powered Fog Machine Just In Time For Halloween

October 27, 2016 by 31 Comments

[makendo] needed a portable fog machine for an upcoming project. It seemed like the kind of a thing a liberal application of money on the Internet could fix in no time. But quality fog machines are too expensive, and the cheap machines are just, well, cheap. Stuck between $800 and quickly broken crap, he decided instead to fashion his own.

Fortunately for him, a recent fad has made it so that a certain segment of the populace absolutely require dramatic clouds of scented drug fog or they get cranky. The market saw an opportunity, cost optimized, and now there are many portable fog machines just waiting to be born in the form of an e-cigarette. However, an e-cigarette needs interaction from a person’s lungs to provide an annoying cloud. So he modeled up a 3D printable case that would blow air into the intake of the e-cigarette. Instead of filling a person’s lungs with a cloud of eye drops and nicotine, it would let out a steady stream of fog.

This device does burn through emitters, because the e-cigarette was not designed for this kind of heavy duty. Even reading the Amazon comments for the $800 dollar version, this is fairly normal for these things. So now [makendo] is able to produce a nice cloud of smoke whenever he needs and it only set him back around $40 US dollars.

Fembot Costume Includes Smoking Nipples

October 31, 2012 by 16 Comments

The greatest of Halloween costumes start with an idea, but they’ve also got to have strong execution to pull the whole thing off. This year  [Johanna Jenkins] decided to put together a Fembot Halloween costume which is a wonderful example of this concept. Going as a Fembot from Austin Powers: International Man of Mystery sounds like a lot of fun right off the bat, but a bit of work at the sewing machine and access to a wig shop in Hollywood really brought it to the next level. But [Johanna] didn’t stop at that. The Fembots have machine guns in their bras. After they’ve torn through all of their ammo they’re left with smoking barrels as nipples, and that final touch even made it into the costume. In the video after the break you can see [Johanna] showing off the small battery operated fog system she piped into the costume bra.

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How NOT To Make Ground-hugging Fog

October 29, 2012 by 35 Comments

Poor [Todd Harrison] spent all of Saturday and Sunday trying to make some ground-hugging fog for his Halloween decor. His fog machine hack turned out to be an utter failure. But he admits it and reports that he still had a lot of fun. Don’t feel bad [Todd], this happens to everyone from time to time. And anyone that has doubts about [Todd’s] skills need not look very far to find out that he does know what he’s doing.

The project started off with a theater-style fog machine. The problem is that this fills a room with a thin foggy-haze that doesn’t take shape outdoors. He wanted that ankle-deep graveyard effect and had seen several examples online that use a fog-machine with a bucked of dry ice. He though he’d just use his own bucket full of regular ice and salt water. Inside the bucket seen above there is a 15′ coil of copper tubing through which the fog machine’s output is passed. On the other side of the bucket there’s a plastic tube that goes to a sheet of plastic meant to distribute the cooled fog.

The problem here is that the fog machine puts out a hot mist. When it hits the ice bath the mist condenses into liquid form and that’s the end of the fog. As he attests in the video after the break, the dry-ice fog hack isn’t pumping out fog. It’s just using the heated steam to pump out carbon-dioxide vapor boiling off of the dry ice.

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Ghostly Images Appear Thanks To Projections On Fog

November 12, 2011 by 28 Comments

This wire-frame cube appears to be floating in mid-air because it actually is. This is a project which [Tom] calls a Laminar Flow Fog Screen. He built a device that puts out a faint amount of fog, which the intense light from a projector is able to illuminate. The real trick here is to get a uniformed fog wall, which is where the laminar part comes in. Laminar Flow is a phenomenon where fluids flow in a perfectly parallel stream, not allowing errant portions to introduce turbulence. This is a favorite trick with water.

[Tom’s] fog screen starts off with a PC fan to move the air. This airflow is smoothed and guided by a combination of a sponge, and multiple drinking straws. This apparatus is responsible for establishing the laminar flow, as the air picks up fog from an ultrasonic fogger along the way.

The only real problem here is that you want the projector shooting off into infinity. Otherwise, the projection goes right through the fog and displays on the wall, ruining the effect. Outdoor applications are great for this, as long as there’s no air movement to mess with your carefully established fog screen.

You can find a short test clip embedded after the break but there are other videos at the link above.

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