FCC To Investigate Raised RF Noise Floor

June 21, 2016 by Jenny List 90 Comments

If you stand outside on a clear night, can you see the Milky Way? If you live too close to a conurbation the chances are all you’ll see are a few of the brighter stars, the full picture is only seen by those who live in isolated places. The problem is light pollution, scattered light from street lighting and other sources hiding the stars.

The view of the Milky Way is a good analogy for the state of the radio spectrum. If you turn on a radio receiver and tune to a spot between stations, you’ll find a huge amount more noise in areas of human habitation than you will if you do the same thing in the middle of the countryside. The RF noise emitted by a significant amount of cheaper modern electronics is blanketing the airwaves and is in danger of rendering some frequencies unusable.

Can these logos really be trusted? By Moppet65535 (Own work) [CC BY-SA 3.0], via Wikimedia Commons

If you have ever designed a piece of electronics to comply with regulations for sale you might now point out that the requirements for RF interference imposed by codes from the FCC, CE mark etc. are very stringent, and therefore this should not be a significant problem. The unfortunate truth is though that a huge amount of equipment is finding its way into the hands of consumers which may bear an FCC logo or a CE mark but which has plainly had its bill-of-materials cost cut to the point at which its compliance with those rules is only notional. Next to the computer on which this is being written for example is a digital TV box from a well-known online retailer which has all the appropriate marks, but blankets tens of megahertz of spectrum with RF when it is in operation. It’s not faulty but badly designed, and if you pause to imagine hundreds or thousands of such devices across your city you may begin to see the scale of the problem.

This situation has prompted the FCC Technological Advisory Council to investigate any changes to the radio noise floor to determine the scale of the problem. To this end they have posted a public notice (PDF) in which they have invited interested parties to respond with any evidence they may have.

We hope that quantifying the scale of the RF noise problem will result in some action to reduce its ill-effects. It is also to be hoped though that the response will not be an ever-tighter set of regulations but greater enforcement of those that already exist. It has become too easy to make, import, or sell equipment made with scant regard to RF emissions, and simply making the requirements tougher for those designers who make the effort to comply will not change anything.

This is the first time we’ve raised the problem of the ever-rising radio noise floor here at Hackaday. We have covered a possible solution though, if stray RF is really getting to you perhaps you’d like to move to the National Radio Quiet Zone.

[via Southgate amateur radio news]

Brutal Water Cannon Defeats Summer Heat; Kills It On Documentation

June 21, 2016 by Dan Maloney 21 Comments

There’s a war on, and while this over-the-top water blaster is certainly an escalation in the Water Wars arms race, that’s not the war we’re referring to. We’re talking about the Documentation War. Hackers, you’re on notice.

If you want to see how a project should be documented, look no further than [Tim]’s forum posts over at WaterWar.net. From the insanely detailed BOM with catalog numbers and links to supplier websites, to scads of build photos with part number callouts, to the finely detailed build instructions, [Tim] has raised the stakes for anyone that documents any kind of build.

And that’s not even touching on the merits of the blaster itself, which has air and water tanks plumbed with every conceivable valve and fitting. There’s even an inline stream straightener made of bundled soda straws to keep the flow as laminar as possible. It looks like [Tim] and his colleagues are obsessed with launching streams of water as far as possible, and although bad weather has prevented an official measurement so far, from the video below it sure looks like he’s covering a huge distance with a stream that stays mostly intact to deliver the full blast to its intended target without losing a drop.

For as much fun as amped-up water guns appear to be, we haven’t seen too many grace these pages before. Going way back we covered a DIY super-soaker. For something much less involved than [Tim’s] masterpiece, you can pull together this pressurized water pistol in an afternoon.

Continue reading “Brutal Water Cannon Defeats Summer Heat; Kills It On Documentation” →

Hackaday Prize Entry: DIY Automatic Tool Changer

June 20, 2016 by Moritz Walter 27 Comments

Choosing between manually changing endmill bits on a CNC machine and investing in an expensive automated solution? Not for [Frank Herrmann], who invented the XATC, an eXtremely simple Automated Tool Changer. [Frank’s] ingenious hack achieves the same functionality as an industrial tool changer using only cheap standard hardware you might have lying around the workshop.

Like many ATCs, this one features a tool carousel. The carousel, which is not motorized, stores each milling bit in the center bore of a Gator Grip wrench tool. To change a tool, a fork wrench, actuated by an RC servo, blocks the spindle shaft, just like you would do it to manually change a tool. The machine then positions the current bit in an empty Gator Grip on the carousel and loosens the collet by performing a circular “magic move” around the carousel. This move utilizes the carousel as a wrench to unscrew the collet. A short reverse spin of the spindle takes care of the rest. It then picks another tool from the carousel and does the whole trick in reverse.

The servo is controlled via a WiFi connected NodeMCU board, which accepts commands from his CNC controller over HTTP. The custom tool change sequences are provided by a few JavaScript macros written for the TinyG workspace on chilipeppr.com, a browser-based G-code host. Enjoy the video of [Frank Herrmann] explaining his build!

Thanks to Smoothieboard creator [Arthur Wolf], who is currently working on a similar project, for the tip!

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Add USB OTG To A USB Thumb Drive

June 20, 2016 by Richard Baguley 33 Comments

Every hacker has a USB thumb drive on their keyring, filled with backup files and a way to boot up a broken computer. One feature that most are missing though is USB On The Go (OTG) support, which allows a USB device to act as a USB host, connecting to devices like cell phones and tablets.

That can be added with the addition of a USB OTG adapter, though, and [usbdevice] has produced a nice how-to on soldering one of these permanently into a USB thumb drive to create a more flexible device. It’s a simple solder-something-on-something-else hack, but it could be handy.

There are a few caveats, though: it needs a USB thumb drive with solderable headers, which most of the smallest drives that have connectors right on the PCB won’t have. Most of the larger drives will have these, though, and they are cheap, so finding a suitable victim isn’t hard.

1000 CPUs On A Chip

June 20, 2016 by Al Williams 42 Comments

Often, CPUs that work together operate on SIMD (Single Instruction Multiple Data) or MISD (Multiple Instruction Single Data), part of Flynn’s taxonomy. For example, your video card probably has the ability to apply a single operation (an instruction) to lots of pixels simultaneously (multiple data). Researchers at the University of California–Davis recently constructed a single chip with 1,000 independently programmable processors onboard. The device is energy efficient and can compute up to 1.78 trillion instructions per second.

The KiloCore chip (not to be confused with the 2006 Rapport chip of the same name) has 621 million transistors and uses special techniques to be energy efficient, an important design feature when dealing with so many CPUs. Each processor operates at 1.78 GHz or less and can shut itself down when not needed. The team reports that even when computing 115 billion instructions per second, the device only consumes about 700 milliwatts.

Unlike some multicore designs that use a shared memory area to communicate between processors, the KiloCore allows processors to directly communicate. If you are just a diehard Arduino user, maybe you could scale up this design. Or, if you want to make use of the unused power in your video card under Linux, you can always try to bring KGPU up to date.

[Clinton] Builds A Better Handgun

June 20, 2016 by Brian Benchoff 121 Comments

A few months ago, we caught wind of someone doing something remarkable. [Clinton Westwood] built a pistol from plans he found on the Internet. You can find plans to build anything on the web, from houses to four-stroke engines to perpetual motion machines. Most of the time these plans are incomplete and many of these devices have never been built at all. [Clinton]’s pistol was one of these never-built designs. After months of work, he’s ready to call this project done, and managed to build an awesome rig to rifle the barrel.

Before [Clinton] set out to build this gun from scratch, the only other example these plans could build a gun-shaped object were a few terrible pictures of what appears to be a gun that was thrown into a garbage disposal, then into a creek, then forgotten for several years. There is a distinct lack of workmanship in this one exemplar, but [Clinton]’s attempt at replication is far more professional.

Although this gun is designed to be built using simple tools, there is one aspect of amateur gunsmithing that requires some specialized equipment. The barrel must be rifled if you want any accuracy at all, and for this [Clinton] has come up with a very simple jig made out of a broken bicycle and some threaded rod.

If homebrew gunsmithery is your thing, but you’re looking for something with a little more punch than a .25 ACP, you can beat plowshares into an AK-47. All hail the shovel AK, defender of the motherland and digger of holes.

Mosaic Palette: Single Extruder Multi-Color And Multi-Material 3D Printing

June 20, 2016 by Gerrit Coetzee 32 Comments

Lots of solutions have been proposed and enacted for multi-color and multi-material 3D printing, from color mixing in the nozzle to scripts requiring manual filament change. A solution proposed fairly early on was to manually splice the filament together, making a custom spool. The printer would print as normal, but the filament would change color. This worked pretty well, but it was tedious and it wasn’t entirely possible to control where the color change happened on the model.

You’ll find some examples of the more successful manual splicing hacks in the pictures below. Scroll down a bit further to find our interview with Mosaic Manufacturing at Bay Area Maker Faire 2016. They have a new product that automates the filament splicing process with precision as the ultimate goal. It unlocks a single extruder printer to behave like a multi-extruder model without stopping and starting.

Terminus’s Ultrasonic Splicer http://www.thingiverse.com/thing:297380

Malcom’s Handheld Splicer http://www.thingiverse.com/thing:16258

RichRap’s Filament Joiner http://www.thingiverse.com/thing:297380

Mosaic pulled off a very difficult combination of two methods mentioned above. Their flagship product is a machine they’ve dubbed, “Palette”. It’s an automatic filament splicer. Up to four different filaments can feed into Palette, and it will splice them at determined intervals. This would be cool by itself, if only to save the tedium of splicing and winding a custom spool by hand.

The real killer app with Palette, however, is the software that runs alongside it. Palette can take the GCODE output of any properly prepared multi material file from any slicer, and then precisely combine and splice the filament. This can feed into any printer without modifying it, aside from sticking an encoder somewhere in the filament path. The results are indistinguishable from a dual, or quad extruder set-up.