Modder puts Computer inside a Power Supply

When building a custom computer rig, most people put the SMPS power supply inside the computer case. [James] a.k.a [Aibohphobia] a.k.a [fearofpalindromes] turned it inside out, and built the STX160.0 – a full-fledged gaming computer stuffed inside a ATX power supply enclosure. While Small Form Factor (SFF) computers are nothing new, his build packs a powerful punch in a small enclosure and is a great example of computer modding, hacker ingenuity and engineering. The finished computer uses a Mini-ITX form factor motherboard with Intel i5 6500T quad-core 2.2GHz processor, EVGA GTX 1060 SC graphics card, 16GB DDR4 RAM, 250GB SSD, WiFi card and two USB ports — all powered from a 160 W AC-DC converter. Its external dimensions are the same as an ATX-EPS power supply at 150 L x 86 H x 230 D mm. The STX160.0 is mains utility powered and not from an external brick, which [James] feels would have been cheating.

For those who would like a quick, TL;DR pictorial review, head over to his photo album on Imgur first, to feast on pictures of the completed computer and its innards. But the Devil is in the details, so check out the forum thread for a ton of interesting build information, component sources, tricks and trivia. For example, to connect the graphics card to the motherboard, he used a “M.2 to powered PCIe x4 adapter” coupled with a flexible cable extender from a quaint company called Adex Electronics who still prefer to do business the old-fashioned way and whose website might remind you of the days when Netscape Navigator was the dominant browser.

As a benchmark, [James] posts that “with the cover panel on, at full load (Prime95 Blend @ 2 threads and FurMark 1080p 4x AA) the CPU is around 65°C with the CPU fan going at 1700RPM, and the GPU is at 64°C at 48% fan speed.” Fairly impressive for what could be passed off at first glance as a power supply.

The two really interesting take away’s for us in this project are his meticulous research to find specific parts that met his requirements from among the vast number of available choices. The second is his extremely detailed notes on designing the custom enclosure for this project and make it DFM (design for manufacturing) friendly so it could be mass-produced – just take a look at his “Table of Contents” for a taste of the amount of ground he is covering. If you are interested in custom builds and computer modding, there is a huge amount of useful information embedded in there for you.

Thanks to [Arsenio Dev‏] who posted a link to this hilarious thread on Reddit discussing the STX160.0. Check out a full teardown and review of the STX160.0 by [Not for Concentrate] in the video after the break.

Posted in ATX case, atx power supply, atx psu, ATX-EPS, case modding, Computer Hacks, EVGA GTX 1060, Gaming Computer, gpu, graphics card, GTX 1060, Intel i5 6500T, mini-itx, modding, Small Form Factor | Leave a comment

Retrotechtacular: How To Repair A Steam Locomotive

Steam locomotives, as a technological product of the 19th century, are not what you would imagine as fragile machines. The engineering involved is not inconsequential, there is little about them that is in any way flimsy. They need to be made in this way, because the huge energy transfer required to move a typical train would destroy lesser construction. It would however be foolish to imagine a locomotive as indestructible, placing that kind of constant strain on even the heaviest of engineering is likely to cause wear, or component failure.

A typical railway company in the steam age would therefore maintain a repair facility in which locomotives would be overhauled on a regular basis, and we are lucky enough to have a 1930s film of one for you today courtesy of the British London Midland and Scottish railway. In it we follow one locomotive from first inspection through complete dismantling, lifting of the frame from the wheels, detaching of the boiler, inspection of parts, replacement, and repair, to final reassembly.

We see steps in detail such as the set-up of a steam engine’s valve gear, and it is impressed upon us how much the factory runs on a tight time schedule. Each activity fits within its own time window, and like a modern car factory all the parts are brought to the locomotive at their allotted times. When the completed locomotive is ready to leave the factory it is taken to the paint shop to emerge almost as a new machine, ready for what seems like a short service life for a locomotive, a mere 130 thousand miles.

The video, which we’ve placed below the break, is a fascinating glimpse into the world of a steam locomotive servicing facility. Most Hackaday readers will never strip down a locomotive, but that does not stop many of them from having some interest in the process. Indeed, keen viewers may wish to compare this film with “A Study in Steel“, another film from the LMS railway showing the construction of a locomotive.

LMS Jubilee class number 5605, “Cyprus”, the featured locomotive in this film, was built in 1935, and eventually scrapped in 1964 as part of the phasing out of steam traction on British railways.

Posted in locomotive, railroad, railway, Retrotechtacular, steam locomotive, transportation hacks | Leave a comment

A Giant Magellan Telescope Needs Giant Mirrors

The Giant Magellan Telescope doesn’t seem so giant in the renderings, until you see how the mirrors are made.

The telescope will require seven total mirrors each 27 feet (8.4 meters) in diameter for a total combined diameter of 24.5 meters. Half of an Olympic size pool’s length. A little over four times the diameter of the James Webb Space Telescope.

According to the website, the mirrors are cast at the University of Arizona mirror lab and take four years each to make. They’re made from blocks of Japanese glass laid out in a giant oven. The whole process of casting the glass takes a year, from laying it out to the months of cooling, it’s a painstaking process.

Once the cooling is done there’s another three years of polishing to get the mirror just right. If you’ve ever had to set up a metal block for precision machining on a mill, you might have an idea of why this takes so long. Especially if you make that block a few tons of glass and the surface has to be ground to micron tolerances. A lot of clever engineering went into this, including, no joke, a custom grinding tool full of silly putty. Though, at its core it’s not much different from smaller lens making processes.

The telescope is expected to be finished in 2024, for more information on the mirror process there’s a nice article here.

Posted in giant, giant engineering, James, Magellan, mirror, mirror making, misc hacks, space, space is cool, telescope, telescope mirror, webb | Leave a comment

Racing Simulator Built From Scrapheap Finds

Paradise means something different for everyone, it could be a sitting by a fire on a rainy night or lying on a sun-kissed beach. But for us, and makers like [liltreat4you], it’s a well stocked scrap pile out behind the house. After buying a racing wheel and pedals for his Xbox, he took a trip out to his little slice of paradise and found nearly all the hardware he needed to build a professional looking race simulator. According to his breakdown, most of the money he spent on this build ended up going into that sweet red paint job and the speed-enhancing stickers.

Everything the light touches is our kingdom.

Not all of us are as lucky as [liltreat4you], and we probably won’t just happen upon a driver’s seat out of a Mazda, or a bunch of perfectly bent metal pipes from an old trampoline out on the back forty. But trolling Craigslist or cruising around for flea markets can still get you parts like these for cheap, so try not to be too discouraged if your backyard isn’t quite as well stocked.

Once he had the metal pipes and seat from the car, the rest of the build came together pretty quickly. After building an oval out of his salvaged pipes, he attached the seat and the arms that would eventually hold the steering wheel and display. A plate was also added at the bottom for the pedals to sit on. By using long bolts, [liltreat4you] was even able to add a degree of adjustment to the wheel position. Being that he got his seat out of a real car, there’s the usual adjustment you’d expect there as well.

Speaking of which, [liltreat4you] casually mentions that you should disconnect the battery of the donor vehicle before taking out the seat, as it’s possible that the removal of the seat or the disconnection of the seat harness can cause the airbags to deploy. We can neither confirm nor deny this, but it’s probably safe advice to follow.

The purists out there may claim that what [liltreat4you] has put together doesn’t quite meet the definition of simulator in its current form. But with the addition of some instrumentation and just a bit of physical feedback, he’ll be well on his way to the complete driving experience.

Posted in hardware, junk, racing, salvaged, video games, Virtual Reality, xbox, Xbox Hacks | Leave a comment

Precision Voltage Reference Source

[barbouri] found a few old (vintage?) parts from the early ’80’s while rummaging through his parts bin, and quickly spun out a small PCB to build a 10.000 V reference using these old ICs. Throwing together a small number of parts, he was able to build a source which might be good enough to use as a reference for another circuit or provide a quick calibration check for some of his bench instruments that have a resolution of 1 mV or maybe even 100 μV.

The AD584* pin programmable precision voltage references have been available since the ’80’s and offer four programmable output voltages of 10.000 V, 7.500 V, 5.000 V, and 2.500 V. The chip is laser-trimmed to ensure high accuracy and low temperature coefficient and requires just a few external components to function. It is available in TO-99 hermetically sealed metal can and 8-pin DIP variants. The “S” version of the device that [barbouri] used provides a temperature coefficient of 30 ppm/°C max over a -55 °C to +125 °C temperature range but other versions of the chip offer a better stability. Analog Devices seem to have discontinued the “L” version (pdf), since it is no longer listed in the current data sheet, but you can still get them from a few sources. The “L” version has a temperature coefficient of just 5 ppm/°C.

Using quality parts such as high stability resistors and TO-99 PTFE socket with gold-plated contacts, his observations confirm that the unit is stable within 30 μV, with a very slow voltage increase of a few microvolts every 6 hours. A 15 V linear regulator powers the device with input power coming from an external wall wart. A small aluminum enclosure houses the device, with two gold-plated 4 mm sockets for the output. If you would like to build your own, his board design is hosted on OSH park, or you can download the Eagle CAD design files. He’s posted all links on his blog post, and provides part numbers for all of the parts used. [barbouri] has been doing a good job of building handy devices for his work bench – check out his well-built milli Ohm Meter that we had featured earlier.

Posted in AD584, calibrator, hardware, TO-99, voltage reference | Leave a comment

A Passion for the Best is in Mechanical Keyboards

There is an entire subculture of people fascinated by computer keyboards. While the majority of the population is content with whatever keyboard came with their computer or is supplied by their employer — usually the bottom basement squishy membrane keyboards — there are a small group of keyboard enthusiasts diving into custom keycaps, switch mods, diode matrices, and full-blown ground-up creations.

Ariane Nazemi is one of these mechanical keyboard enthusiasts. At the 2017 Hackaday Superconference, he quite literally lugged out a Compaq with its beautiful brominated keycaps, and brought out the IBM Model M buckling spring keyboard.

Inspired by these beautiful tools of wordcraft, [Ariane] set out to build his own mechanical keyboard and came up with something amazing. It’s the Dark Matter keyboard, a custom, split, ergonomic, staggered-columnar, RGB backlit mechanical keyboard, and at the 2017 Hackaday Superconference, he told everyone how and why he made it.

A rubber dome keyboard. The only spring pressure comes from a sheet of rubber

Ninety-nine percent of the keyboards you’ll ever see are crappy rubber dome keyboards. This is a specific type of switch, made with two contacts on a PCB, a sheet of rubber with a bunch of little bubbles in it, and a conductive foam pad mounted to the bottom of a key. The keys get their springiness from these rubber domes, and when a key is pressed it smashes into the PCB contacts, closing a circuit.

It’s certainly an inexpensive way to build a keyboard, but compared to a true mechanical switch it feels like crap. The key doesn’t activate until it hits bottom, and the lifetime of each of these switches is measured in the tens of thousands of cycles instead of the millions of cycles a mechanical keyswitch can handle.

The Cherry MX Blue keyswitch

On the other end of the spectrum is a mechanical keyswitch, best represented by the Cherry MX switch; a make and model of switch, with clones also built by Gateron and Kailh. These switches use actual springs and bits of brass to close a switch and they provide tactile feedback to the typist. There are even different varieties of MX-style switch; the ones with red stems are almost linear in their feedback, while browns, clears, and blues have a little bit of resistance in the middle of the key’s travel. The blues are clicky and are somehow even louder than the buckling springs found in the IBM Model M. They sound like a machine gun, and it’s awesome.

An entire community has grown up around putting these MX-style switches into custom designed enclosures for the perfect typing experience. There are innovations in ergonomics like columnar spacing, where the Q, A, and Z keys are in a straight line. There are split keyboards, where the left and right side of the keyboard are attached by a cable. Ariane decided he wanted the ultimate keyboard. It would be a split keyboard, and it should have a columnar layout. Because he’s part of the Hackaday crowd, this keyboard must have a ton of blinkies. This led to the creation of the Dark Matter keyboard, one of the most technologically impressive keyboards we’ve seen in a long time.

Like a lot of mechanical keyboard projects, Ariane is using a Teensy as the controller for each half of his keyboard. Unlike most mechanical keyboard projects, Ariane is using the Teensy LC, the cost-reduced version of this family of dev boards. Until very recently, the most popular firmwares for keyboards haven’t been brought over to the Teensy LC. Ariane did just that, and added support for driving WS2812 RGB LEDs. Combine this with an MX-compatible keyswitch with a clear housing and some polycarbonate keycaps, and Ariane made the blinkiest keyboard you’ve ever seen that doesn’t have individual OLED displays embedded in each keycap.

Ariane’s talk is a wealth of information on how to manufacture keyboards, from firmware and software development to how to build an enclosure. Keyboards are a surprisingly popular side topic in our little niche here on Hackaday, and we’re pleased Ariane could give this talk and extol the virtues of mechanical keyboards.

Posted in 2017 Hackaday Superconference, Ariane Nazemi, cons, Dark Matter Keyboard, Hackaday Columns, keyboard, mechanical keyboard | Leave a comment

Radio Apocalypse: The GWEN System

Recent developments on the world political stage have brought the destructive potential of electromagnetic pulses (EMP) to the fore, and people seem to have internalized the threat posed by a single thermonuclear weapon. It’s common knowledge that one bomb deployed at a high enough altitude can cause a rapid and powerful pulse of electrical and magnetic fields capable of destroying everything electrical on the ground below, sending civilization back to the 1800s in the blink of an eye.

Things are rarely as simple as the media portray, of course, and this is especially true when a phenomenon with complex physics is involved. But even in the early days of the Atomic Age, the destructive potential of EMP was understood, and allowances for it were made in designing strategic systems. Nowhere else was EMP more of a threat than to the complex web of communication systems linking far-flung strategic assets with central command and control apparatus. In the United States, one of the many hardened communications networks was dubbed the Groundwave Emergency Network, or GWEN, and the story of its fairly rapid rise and fall is an interesting case study in how nations mount technical responses to threats, both real and perceived.

Reliability Through Physics

GWEN began as a patch for a perceived gap in the communications network connecting the country’s strategic nuclear assets — primarily the launch control centers (LCC) of the ballistic missile launch facilities — to the National Command Authority, which is basically the president. Like all strategic communications systems, GWEN was designed to incorporate best practices for surviving the electromagnetic effects of an EMP. But GWEN had another mission.

Ground wave propagation. Source: Electronics Notes

Groundwave propagation is the tendency of certain radio waves to hug the surface and follow the curvature of the earth and is an exception to the general rule that radio waves only travel in straight lines. The earth acts as a conductor below 5 MHz, so radio waves traveling along the surface of the earth induce currents. The induced currents slow down propagation near the surface, curving the wavefront down as it spreads out. There is considerable attenuation of the signal, of course, and careful consideration has to be given to antenna design and construction. But when properly engineered, ground wave propagation systems can be very effective at over-the-horizon communications that do not rely on the ionosphere.

Groundwave propagation requires long wavelengths to work, so GWEN operated in the low frequency (LF) band from 150 to 175 kHz, well below the commercial AM radio medium frequency (MF) band from 530 to 1700 kHz.

GWEN Nodes

A GWEN relay node. Source: Wikipedia, public domain.

GWEN was envisioned as a wide area network of LF relay nodes about 150 to 200 miles apart. Each GWEN relay node communicated to input-output nodes, which were generally located at Air Force bases and other such facilities. The relay nodes were to take command and control messages from the IO nodes and propagate them over the entire network until they reached receive-only nodes, typically the LCC bases. GWEN encoded messages on the LF signals using minimum-shift keying at a data rate of 1200 bps. Messages were encrypted, of course.

Only about 58 of the planned 240 GWEN stations were built between 1982 and the early 1990s, when the program was shut down. GWEN was mostly a victim of Congress, who were unwilling to fund what they perceived to be a Cold War relic after the fall of the Soviet Union. There was also a certain amount of NIMBY-ism with regard to future GWEN sites; with the increasingly popular perception that everything from power lines to cell towers were capable of causing profound biological effects, the prospects of having a powerful radio transmitter that would also be a possible war target in the neighborhood was more than enough reason to mothball the program.

By that time, GWEN’s technology was certainly looking a little long in the tooth anyway, with the rise of the Internet and the proliferation of satellite communications. This may prove shortsighted, though; while there’s certainly a lot of redundancy built into today’s strategic communication systems, there’s something to be said for a simple and robust system that uses basic physical principle like GWEN did.

Posted in emp, Featured, ground wave, history, ionosphere, LF, low frequency, network, Original Art, propagation, wireless hacks | Leave a comment

Fail of the Week: Cheap Chips Cause Chaos

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Posted in ad633, AliExpress, Bangood, counterfeit parts, ebay, Fail of the Week, fake, false, faux, parts | Leave a comment

Skin (Effect) in the Game

We love to pretend like our components are perfect. Resistors don’t have capacitance or inductance. Wires conduct electricity perfectly. The reality, though, is far from this. It is easy to realize that wire will have some small resistance. For the kind of wire lengths you usually encounter, ignoring it is acceptable. If you start running lots of wire or you are carrying a lot of current, you might need to worry about it. Really long wires also take some time to get a signal from one end to the other, but you have to have a very long wire to really worry about that. However, all wires behave strangely as frequency goes up.

Of course there’s the issue of the wire becoming a significant part of the signal’s wavelength and there’s always parasitic capacitance and inductance. But the odd effect I’m thinking of is the so-called skin effect, first described by [Horace Lamb] in 1883. [Lamb] was working with spherical conductors, but [Oliver Heaviside] generalized it in 1885.

Put simply, when a wire is carrying AC, the current will tend to avoid traveling in the center of the wire. At low frequencies, the effect is minimal, but as the frequency rises, the area in the center that isn’t carrying current gets larger. At 60 Hz, for example, the skin depth for copper wire — the depth where the current falls below 1/e of the value near the surface — is about 0.33 inches. Wire you are likely to use at that frequency has a diameter less than that, so the effect is minimal.

However, consider a 20 kHz signal — a little high for audio unless you are a kid with good ears. The depth becomes about 0.018 inches. So wire bigger than 0.036 inches in diameter will start losing effective wire size. For a 12-gauge wire with a diameter of 0.093 inches, that means about 25% of the current-handling capacity is lost. When you get to RF and microwave frequencies, only the thinnest skin is carrying significant current. At 6 MHz, for example, copper wire has a skin depth of about 0.001 inches. At 1 GHz, you are down to about 0.000081 inches. You can see this (not to scale) in the accompanying image. At DC, all three zones of the wire carry current. At a higher frequency, only the outer two zones carry significant current. At higher frequencies, only the outer zone is really carrying electrons.

So What?

There are a few practical issues to think about. Manufacturers that create cables for high-frequency use spend a lot of time perfecting the surface of the wire since a small imperfection on the surface that isn’t significant to the entire diameter of the wire might be a very important part of the current-handling capacity at a high frequency.

Cables that are copper clad — that is, that have a steel core and a copper surface — will conduct DC differently than AC at the design frequency. Some very high power applications save weight and cost by using hollow tubes instead of solid conductors. This is very common in transmitting coils that use what appears to be copper plumbing tubes. Electric power stations often use tube conductors, also, and benefit from the ability of a tube to stretch across a long distance without as much support as a heavier wire. Sometimes these tubes are silver plated since the plating will carry most of the current and silver is a good conductor but relatively expensive.

To mitigate skin effect, you can use litz wire for frequencies up to about 1 MHz. This is wire woven from many separate, insulated conductors. In addition to providing multiple “skins” for the current to flow, the weaving follows certain patterns to minimize the proximity effect between the wires. If you’ve ever taken apart an old AM radio with a ferrite rod antenna inside, you’ve probably seen litz wire as most of those antennas employ litz windings. Carbon nanotube threads can also work and are not as limited in frequency.

Another place this shows up is in welding rods. An iron rod will work fine for welding at DC, but not for high-frequency welding. The reduced current-handling capacity will cause the welding power to dissipate in heat throughout the rod instead of causing an arc.

The Math

The theory behind skin effect is that the change in current causes a change in magnetic field and that generates a reverse voltage (“back EMF”) in the wire. This reverse is strongest in the center of the wire and it forces the electrons away from the center. This is the same effect, by the way, that causes metals to reflect electromagnetic waves.

There is a complex formula for the skin depth that depends on the material’s resistivity, magnetic permeability, and other exotic values. However, as a rule of thumb, you can ignore the skin effect when the frequency is at or below 124 divided by the square of the wire diameter in thousandths of an inch. Beyond that point, assume resistance will increase about 3.2 times for every 10X increase in frequency.

For example, consider a two-inch piece of #18 wire. At DC, the wire would have a 1.06 mΩ resistance. The diameter in mils is 40.3. Squaring 40.3 and dividing it into 124 gives 76 kHz. Suppose you were going to use the wire at 100 MHz. Since this is just an estimate, consider that 100 kHz is three decades below 100 MHz and you can figure the resistance will be 1.06 x 3.2 x 3.2 x 3.2 = about 35 millohms. If you do the long math, the real answer comes out to just under 41 milliohms, so that’s not bad.

If you really want to look at the hairy math, you might enjoy the video below.

In Practice

Most of the time, you won’t care much about skin effect. That’s what makes it so insidious. We all know batteries, for example, don’t behave like ideal voltage sources and so we work around it. But wires are pretty good, until they aren’t. Long wires, high frequencies, and high currents can all conspire to make the pretty schematic an ugly circuit. Skin effect is just one of the reasons wires don’t behave like we wish they would.

Photo credit: Title graphic [Mariusz.stepien] CC BY-SA 3.0

Posted in ac, Engineering, hackaday 101, Hackaday Columns, radio, RF, skin effect | Leave a comment

Hacking A K40 Laser Cutter

The distinctive blue-and-white enclosure of the Chinese-made K40 laser cutter has become a common sight in workshops and hackerspaces, as they represent the cheapest route to a working cutter that can be found. It’s fair to say though that they are not a particularly good or safe machine when shipped, and [Archie Roques] has put together a blog post detailing the modifications to make something better of a stock K40 performed at Norwich Hackspace.

After checking that their K40 worked, and hooking up suitable cooling and ventilation for it, the first task facing the Norwich crew was to install a set of interlocks. (A stock K40 doesn’t shut off the laser when you open the lid!) A switch under the lid saw to that, along with an Arduino Nano clone to aggregate this, a key switch, and an emergency stop button. A new front panel was created to hold this, complete a temperature display and retro ammeter to replace the modern original.

Norwich’s laser cutter has further to go. For example, while we secretly approve of their adjustable bed formed from a pile of beer mats, we concede that their plans to make something more practical have merit. The K40 may not be the best in the world, indeed it’s probable we should be calling it an engraver rather than a cutter, but if that means that a small hackerspace can have a cutter and then make it useful without breaking the bank, it’s good to see how it’s done.

This isn’t the first K40 enhancement we’ve featured. Norwich might like to look at this improved controller, or even extend their cutter’s bed. Meanwhile if [Archie]’s name rings a bell, it might be because of his Raspberry Pi laptop.

Posted in K40, laser, laser cutter, laser hacks | Leave a comment