Lumographic Images Created With Lens Only

Lumographic images are those patterns you see at the bottom of swimming pools. When water works as a lens, the light patterns of bright and dark are random and wandering based on the waves above. [Matthew] figured out a way to create fixed images from lens shape alone. The images only morph into view clearly when light shines at the proper angle. At near angles an eerie fun-house mirror effect appears, but too far off and it scatters unrecognisably.

The exact method for designing the optics is not explained, though we are sure someone in our readership could figure it out. The artist claims it to be a hundred year old million-variable math problem. The lenses are often quite thick and do not resemble much of anything. The effect however, is sharp, clear and detailed.

At first he suspected he needed astronomically-expensive military-grade 50 nanometer (0.000002″) precision machining for the lenses, but some friends in the autobody industry gave him a few tips to squeeze good enough accuracy from more affordable industrial machines. The technique also allows for images to appear from mirrors and internal reflections. It is probably not something you can 3D print or machine yourself, but it would be interesting to see someone try.

[Matthew]’s work is on display in the “Composite” gallery at the National Museum of Math in New York (MoMath). See the video after the break for a peak at the machinery he uses to manipulate the lenses to enhance the visuals in the exhibit.

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Tripping on Oscilloshrooms With an Analog Scope

This might be an old trick, but it’s still cool to see a functional tool like the oscilloscope manipulated for an unrelated purpose such as this. [Jerobeam Fenderson] made a video explaining how to input stereo audio into an old digital scope in order to create of all things, dancing mushrooms… because why not?

In this case, [Jerobeam] used a Tektronix D11 5103N set in X Y mode and attached the left and right channels from his RME Fireface UC audio interface. One channel corresponds with X, and the other with Y. From here, he controls the wave forms discretely with the help of software like Pure Data (Pd) and Max (not free, but more powerful) which are visual programming environments made to enable musicians and artists to create software without writing lines of code. His video explains how to make a circle out of a sine wave, and then beat the crap out of it with math far beyond our comprehension. The outcome is pretty mesmerizing and leaves us wanting to try it out ourselves. Luckily, if you’re interested in experimenting with the voice of sine waves… [Jerobeam] has more information on his blog on how to do some scope play of your own whether your hardware is analog or digital.

You can see the dancing mushrooms in his video below:

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2014 Advent Calender of Circuits

Every day this month and until Christmas, [vk2zay] is (has already been!) posting a simple but useful hack in his 2nd sort-of-annual “Advent Calender of Circuits” that many of you will want to be bookmarking. For those already saturated with the season of holiday hacks, don’t worry – other than being festively generous of him to tutor and demo a new hack every day, the hacks themselves have nothing to do with Christmas. Though he missed the last couple years we here at Hackaday covered his first month of hacks back in 2011 (now in playlist).

The daily hacks posted so far cover a wide variety of useful projects (leaning towards HV) for the electronics hobbyist who might not have all the fancy tools in their shop: DIY high voltage probes, a 1-hour tesla coil from junk, measuring RF power, a stud detector, how to test an  unknown transformer’s saturation, and many others. We cannot predict what will be posted the rest of the calender (the author hints to be making them up as he goes), but by now it is safe to say that they will not disappoint.

We would be stealing his thunder to cover them all, so, we will just pick our favorite for now:

The 1-hour tesla coil is a delightful all-shortcuts-taken hack project. If one were to listen to aficionados, teslacoiling is a highly precise hobby to get into. It appears to require careful planning, much calculation, special-ordered or soviet-surplus parts, custom jigs, fine tuning, etc. [vk2zay] shows otherwise.

Every single component of the assembly is itself a hack.

No fancy tungsten-infused grade 8 copper being water-cooled via heat pump here – the spark gap is just the bent leg of a capacitor hovering near the start of the primary winding. The power supply is a backlight inverter with a chain of Cockcroft-Walton voltage doublers. The high voltage resistor is a bunch of series-chained resistors shoved into a silicone tube. The topload is a couple cheap pie tins masking-taped together to “resemble something like a sphere.” The primary is a loose, unsupported spring of copper wire. The secondary was calculated to be whatever the height of the tube he had handy and coiled only as smoothly as a first attempt would allow. He does not even bother using wires or a switch – the circuit is completed by clipping a couple of test leads.

After all this hodgepodgery the circuit was then carefully tuned to optimize how little time it took to build (additional time used: zero). Since the frequencies do not match (1.7 vs. 2.6 mhz – 35% apart) the only thing this circuit resonates with is a hacker’s appeal for making do. Does not matter, still works. The streamers easily reach 2 inches and the author claims double that in dark lighting.

In the just 6 minute video he also manages to explain roughly what is going on theory-wise and suggest the time-effective things to considering upgrading. Almost a dozen hacks in the bag and over a dozen more to come before Christmas.

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Casting Engagement Rings (Or Other Small Metal Parts!)

[Paul Williams] wrote in to tell us about his most recent and dangerous endeavor. Marriage.

As a masters student in Mechanical Engineering, he wanted to give his wife (to be) to be a completely unique engagement ring — but as you can imagine, custom engagement rings aren’t cheap. So he decided to learn how to make it himself.

During the learning process he kept good notes and has produced a most excellent Instructable explaining the entire process — How to make the tools you’ll need, using different techniques and common problems you might have. He even describes in detail how to make your own mini-kiln (complete with PID control), a vacuum chamber, a wax injector and even the process of centrifugal casting. Continue reading “Casting Engagement Rings (Or Other Small Metal Parts!)”

Ephemeral Photographs Staged with Artful Inventions

[Gordon Kirkwood’s] focus as a photographer is in capturing ephemeral phenomena, that is, things that are exhilarating to see but also fleeting. In the pursuit of documenting such blips of beauty found in the natural word, he has taken on engineering the circumstance through which they occur by means of technology.

One of the amazing mechanical creations he’s constructed to aid in his photography is a large computer controlled, bubble blower. A few stepper motors work to dilate three segments of soap-soaked rope engaged at 120 degree angles to create a triangular aperture. When the aperture closes, the segments overlap slightly, covering themselves with a consistent coating of suds. When the segments stretch apart, a fan blows a current of air towards the center, pushing the sheath of fluid into ginormous glimmering orbs which he uses as the focal point in some of his photographs.

bubbleAparatus

More currently, [Gordon] has been developing a body of work that involves zapping botanical subject matter with a quarter-million volts from a portable arc producing device he’s created and capturing the reaction with an ultra low-tech camera (the kind with the bellow and sheet you hide under while exposing the film). Using a method all his own, the shots recorded on large format film are claimed to turn out with even more clarity than any current digital camera in use today. [Gordon] has launched a crowd funding campaign to support a pilgrimage to the majestic island of Hawaii, where he’ll use his lightning producing apparatus on ten different specimens of tropical plant life so that he can record the outcome with his tried and proven technique. (see below an artsy shot of his lightning summoner)

lighteningAparatus

Sometimes Kickstarter isn’t so much about commercialism as it is starting a dialogue with the world and beginning a personal adventure. May the journey lead to new inventions and larger, more ambitious projects! Oh yeah- the bubble blowing machine is a must-see in action. Wicked cool:

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An Expanding Wooden Table

A few years ago, the world of fine woodworking was presented with the Fletcher Capstan table. It’s a round table, able to expand its diameter merely by rotating the top. A gloriously engineered bit of mechanics move the leaves of the tables out while simultaneously raising the inner part of the table. It’s a seriously cool table, very expensive, and something that will probably be found in museums 100 years from now.

[Scott Rumschlag] thought his woodworking skills were up to the task of creating one of these expanding tables and managed to build one in his workshop. Like the Fletcher Capstan table, it’s a table that increases its diameter simply by rotating the table top. Unlike the commercial offering, this one doesn’t cost as much as a car, and you can actually see the internal mechanism inside this table.

The top of [Scott]’s table is made of three pieces. The quarter-circle pieces are the only thing showing when the table is in its minimum position, and are arranged on the top of the ‘leaf stack’. When the table expands, four additional leaves move up from beneath with the help of a linear bearing made of wood and a roller that slides along the base of this mechanical contraption.

The center of the table – the star – is a bit more difficult to design. While the leaves move up the stack of table tops with the help of a ramp, this is an impractical solution for something so close to the center of the table. Instead of a ramp, [Scott] is using a lifting lever and metal hinge that brings the star of the table up to the right level. Even though it’s a crazy amount of woodworking and fine tuning to get everything right, it’s not too terribly difficult to get your head around.

Videos, including one of the assembly of the table, below.

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A Web Connected Seismometer

[10DotMatrix] has a budding interest in seismology, so she decided to make her own seismometer out of some easy-to-find materials. Seismometers are prohibitively expensive for hobbyists, but thankfully it’s really easy to build a usable siesmometer out of simple parts. [10DotMatrix]’s seismometer is built around a modified subwoofer, which acts as a transducer for the earth’s vibrations.

The subwoofer is mounted to the bottom of a tripod, which forms the structure of the seismometer. A slinky is stretched between the top of the tripod and a weight that rests on the coil of the subwoofer. Whenever the ground shakes, the slinky and weight vibrate and induce current in the voice coil.

Since these vibrations are usually quite small, the output of the subwoofer needs a bit of amplification. [10DotMatrix] fed the output of the woofer to an AD620 op amp, which amplifies the signal to a measurable level. The amplifier’s output is fed into an Intel Edison board, which samples the voltage and transmits it to a web dashboard for online viewing.

If you’re shaking with excitement about seismic measurements you’ll surely be interested in this similar method which uses a piezo element as the detector.