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Skull Cane Proves Bondo Isn’t Just for Dents

ศุกร์, 02/23/2018 - 02:30

[Eric Strebel] is quickly becoming a favorite here at Hackaday. He’s got a fantastic knack for turning everyday objects into something awesome, and he’s kind of enough to document his builds for the viewing pleasure of hackers and makers everywhere. It also doesn’t hurt that his voice and narration style gives us a real Bob Ross vibe.

The latest “Happy Accident” out of his workshop is a neat light-up cane made from a ceramic skull found at a local store. But while the finished cane itself might not be terribly exciting, the construction methods demonstrated by [Eric] are well worth the price of admission. Rather than using Bondo like the filler we’re all accustomed to, he shows how it can be used to rapidly build free-form structures and components.

After building up layers of Bondo, he uses a cheese grater to smooth out the rough surface and a hobby knife to clean up the edges. According to [Eric], one of the benefits of working with Bondo like this is that it’s very easy to shape and manipulate before it fully hardens; allowing you to really make things up as you go.

[Eric] also shares a little secret about how he makes his gray Bondo: he mixes some of the toner from a laser printer cartridge into it. This allows you to very cheaply augment the color of the filler, and is definitely something to file away for future reference.

If the video below leaves you hungry for more [Eric Strebel], check out his fantastic series on working with foam core, which should lead you right down the rabbit hole to his DIY foam core spray painting booth.

QuickBASIC Lives On with QB64

ศุกร์, 02/23/2018 - 01:01

When I got my first computer, a second hand 386 running MS-DOS 6.22, I didn’t have an Internet connection. But I did have QuickBASIC installed and a stack of programming magazines the local library was throwing out, so I had plenty to keep myself busy. At the time, I thought QuickBASIC was more or less indistinguishable from magic. I could write simple code and compile it into an .exe, put it on a floppy, and give it to somebody else to run on their own machine. It seemed too good to be true, how could this technology possibly be improved upon?

Of course, that was many years ago, and things are very different now. The programming languages du jour are worlds more capable than the plodding BASIC variants of the 80’s and 90’s. But still, when I found a floppy full of programs I wrote decades ago, I couldn’t help but wonder about getting them running again. With something like DOSBox I reasoned I should be able to install the QuickBASIC IDE and run them like I was back on my trusty 386.

Unfortunately, that was not to be. Maybe I’m just not well versed enough in DOSBox, but I couldn’t get the IDE to actually run any of the source code I pulled off the floppy. This was disappointing, but then it occured to me that modern BASIC interpreters are probably being developed in some corner of the Internet, and perhaps I could find a way to run my nearly 30 year old code without having to rely on 30 year old software to do it.

The QB64 Project

After searching around a bit, I found the very cool QB64 project (alternate site: QB64.org) This is an open source QuickBASIC development environment that is not only completely compatible with existing programs, but adds in functions and capabilities that were unthinkable back on my 386. Displaying a PNG, loading TTF fonts, or playing an MP3 in the background can be accomplished with just one or two commands.

Such things were possible with the original QuickBASIC, but existed more in the realm of tech demos than anything else. Oh the games I could have made back in the day with software like this! I had to be content with bleeps and bloops, and even that required you to figure out the timing for the tones yourself.

Even better, QB64 is cross-platform and supports compiling into native binaries for Linux, Windows, and Mac OS. That meant that not only could I run my old code within the IDE, but I could actually compile it into a binary for my Linux desktop. I don’t own a Windows computer anymore, but with WINE I was able to run the Windows version of QB64 and compile an .exe that I could give to my friends who are still living in the dark ages.

You can even use QB64 to compile QuickBasic code into an Android application, though there’s considerable hoops to jump through and it currently only works on Windows.

Conjuring Black Magic

This might be lost on those who never wrote BASIC code on a vintage machine, but the following code creates a 800×600 screen, puts a full screen PNG up, plays an MP3, and writes a message using a TrueType font.

' Init screen SCREEN _NEWIMAGE(800, 600, 32) ' Load files menubg& = _LOADIMAGE("splash.png") menufont& = _LOADFONT("font.ttf", 30) theme& = _SNDOPEN("theme.mp3", "SYNC,VOL") ' Set theme volume, start playing _SNDVOL theme&, 0.3 _SNDPLAY theme& ' Load font _FONT menufont& ' Show full screen image _PUTIMAGE (0, 0), menubg& ' Say hello PRINT "Hello Hackaday!"

As a comparison, this QuickBasic tool for simply displaying a JPEG image clocks in at 653 lines of code.

Revisiting a Project

In my edgy teenage days, I created a graphical version of the “Drugwars” style game. You moved a little stick man around a pixelated environment, buying and selling substances that I had heard about in movies but certainly had never seen in person. It was terrible. But it was part of my youth and I thought it would be fun to see if I could shoehorn in some modern flash using QB64.

As it turns out, transparent PNGs and the ability to display proper fonts makes things a lot easier. Being able to play music and ambient sound effects in the background makes even sloppily done games seem a lot better. The following screenshots are of the main menu of my little teenage crime fantasy, before and after the application of QB64. Note that the core source code itself is more or less the same, I’m just interleaving it with the ability to load and display external files.

Should You Be Using QuickBasic?

No, you definitely should not. I didn’t write this to try and convince anyone to jump on a programming language that peaked before many of our readers were even born. QuickBASIC is an antiquated language, stuck with outdated methods and limitations that are confounding to the modern programmer. But QB64 does do an excellent job of modernizing this classic language, if only to a relatively small degree in the grand scheme of things, for those of us who cut our teeth on it.

Being able to take a disk with BASIC code I wrote on a DOS 386 in the early 90’s and turn it into a Linux binary in 2018 is a pretty neat accomplishment, and I salute the QB64 development team for making it possible. I won’t be writing any new code in the language, and I don’t suggest you do either, but it was a lot of fun being able to revisit this period in my life and drag it kicking and screaming into the modern era.

France Proposes Software Security Liability For Manufacturers, Open Source As Support Ends

พฤ, 02/22/2018 - 23:30

It sometimes seems as though barely a week can go by without yet another major software-related hardware vulnerability story. As manufacturers grapple with the demands of no longer building simple appliances but instead supplying them containing software that may expose itself to the world over the Internet, we see devices shipped with insecure firmware and little care for its support or updating after the sale.

The French government have a proposal to address this problem that may be of interest to our community, to make manufacturers liable for the security of a product while it is on the market, and with the possibility of requiring its software to be made open-source at end-of-life. In the first instance it can only be a good thing for device security to be put at the top of a manufacturer’s agenda, and in the second the ready availability of source code would present reverse engineers with a bonanza.

It’s worth making the point that this is a strategy document, what it contains are only proposals and not laws. As a 166 page French-language PDF it’s a long read for any Francophones among you and contains many other aspects of the French take on cybersecurity. But it’s important, because it shows the likely direction that France intends to take on this issue within the EU. At an EU level this could then represent a globally significant move that would affect products sold far and wide.

What do we expect to happen in reality though? It would be nice to think that security holes in consumer devices would be neutralised overnight and then we’d have source code for a load of devices, but we’d reluctantly have to say we’ll believe it when we see it. It is more likely that manufacturers will fight it tooth and nail, and given some recent stories about devices being bricked by software updates at the end of support we could even see many of them willingly consigning their products to the e-waste bins rather than complying. We’d love to be proven wrong, but perhaps we’re too used to such stories. Either way this will be an interesting story to watch, and we’ll keep you posted.

Merci beaucoup [Sebastien] for the invaluable French-language help.

French flag: Wox-globe-trotter [Public domain].

Mechanisms: Mechanical Seals

พฤ, 02/22/2018 - 22:00

On the face of it, keeping fluids contained seems like a simple job. Your fridge alone probably has a dozen or more trivial examples of liquids being successfully kept where they belong, whether it’s the plastic lid on last night’s leftovers or the top on the jug of milk. But deeper down in the bowels of the fridge, like inside the compressor or where the water line for the icemaker is attached, are more complex and interesting mechanisms for keeping fluids contained. That’s the job of seals, the next topic in our series on mechanisms.

Packing it In

One of the simplest seals is packing, or compressing some sort of flexible material into a space to control the flow of a fluid. Packing probably dates to at least the time when humans began making boats more complicated than a simple dugout canoe, in response to the fact that it’s really difficult to keep water from leaking between two pieces of wood. Ship seams have been caulked with fibers like hemp and cotton soaked in pitch or tar for millennia.

Marine propeller shaft stuffing box. The gland compresses the seals against the shaft, controlling water flow into the bilge. Source: Engineman 1 & C

A more complex seal, in the form of a stuffing box around the tiller post of an inboard rudder, extended the concept of caulking into a more dynamic environment. A tiller post is a vertical shaft that penetrates the bottom hull of a vessel and connects the submerged rudder to a tiller or other steering gear. To staunch the flow of water through such a gaping wound, a stuffing box was built inside the hull around the shaft and packed full of old rope fibers, rags, bits of sailcloth — anything fibrous and compressible. Soaked with tallow or fat for lubrication and water repellency, the stuffing was compressed with a gland around the shaft that was tightened down under screw pressure or using wedges. Stuffing boxes are still used to this day for all kinds of shafts that penetrate a vessel’s hull, including where the propeller shaft exits the stern, in which case the assembly is called a stern gland.

Maritime tradition has stuck with compression packing. While far from perfect, compression packing seals are cheap and easy to engineer, and so still see service to this day. Compression seals are used in water pumps and as a seal around the pump shaft to keep the process fluid controlled. While the materials used have come a long way, with highly engineered Teflon and graphite packing replacing hemp and lard, the basic technique is still the same — squeeze the packing as tightly as possible around the shaft to make it hard for fluid to penetrate. Hard, but not impossible — compression packing always leaks to some degree. Packed joints therefore require constant maintenance, including frequent tightening of the gland to maintain compression and eventually replacement of the old packing with fresh material.

Sealing the Deal

Ongoing maintenance costs and the tendency of compression packing to wear out the shaft they are wrapped so tightly around are two of the biggest drawbacks to these seals, and so other types of seals for rotating shafts were invented. Your car engine has a ton of seals, but the ones that can cause you to have a really bad day when a mechanic tells you you’ve “blown a seal” are the crankshaft seals. There are usually two, one where the crankshaft exits the crankcase at the rear to connect to the transmission, and one at the front where the crank pulley that runs the water pump, alternator, and other engine accessories exits. Seals are needed around the crankshaft because the crankcase is full of oil; the seals keep the oil inside the engine while allowing the crankshaft to rotate and run the car.

Crankshaft oil seals are known as radial shaft seals or lip seals, where a flexible material is formed into a ring that fills a space between the stationary part (the crankcase in our example) and a rotating shaft (the crankshaft journal). Like compression packing materials, lip seals were once made from natural substances like leather, but today elastomeric substances like Viton and Buna N are used. Most modern oil seals are composite mechanisms, too, with the elastomer bonded to a metal case that can be pressed into a recess in a crankshaft in an interference fit.

Typical radial seal. Note the difference in lip angle between the wet and dry sides. Source: SKF

Radial shaft seals seem simple enough, but there are several critical factors in designing a seal that’ll work. Aside from choices like material compatibility with the process fluids and heat ratings, the geometry of the flexible lip is crucial to the design. Looked at in cross-section, the lip forms a triangular profile with the apex touching the shaft at a single contact point. The angle of the lip on the wet side of the seal must be steeper than the angle on the dry side, so that hydraulic pressure from the process fluid (oil in our crankshaft example) tends to force the seal tighter around the shaft. Process fluid pressure is a major consideration as well — too much and the lip can deform enough to increase the contact area, causing premature wear and failure. That’s why we’re warned that too much oil in an engine can be just as bad as too little — more volume means more pressure, leading to the classic “blown seal” symptom of leaking from either the front or rear of the engine.

For viscous process fluids like grease, a plain elastomeric lip seal might suffice. But thinner fluids generally need extra circumferential force to help keep the lip in firm contact with the shaft. Such seals are likely to incorporate a garter spring into the lip to preload the seal on the shaft and to help make up for any irregularities in the shaft. Garter springs also help compensate for any radial oscillations of a shaft.

We’ve only touched on a few of the hundreds of types of seals for both dynamic and static applications here. The engineering behind them is pretty interesting, though, especially when you realize that it all started with a box of greasy rags.

Featured image source: American High Performance Seals

OBD-Sniffing A Caddy PHEV

พฤ, 02/22/2018 - 19:00

The Cadillac ELR is a plug-in hybrid car with a bit of class, it has the beating heart of a Chevy Volt in a nice coupé body with some up-market styling and a nice interior. Since it wasn’t on the market for long and some consumers are still wary of cars with electric motors, it also represents something of a sweet spot: according to [Andrew Rossignol] you can pick them up for less outlay than you might imagine. He bought one, and being an inquisitive soul decided to probe its secrets through its OBD-II ports.

OBD-II sniffing is nothing especially new, but his write-up provides an interesting run-down of the methodology used to identify the different proprietary pieces of data that it makes available. His Python script attempted to parse the stream as though it were multi-byte words of different lengths, plotting its results as graphs, It was then a straightforward process of identifying the graphs by eye that contained useful data and rejecting those that were obviously garbage. He was able to pick out the figures in which he was interested, and write an interface for his little Sony VAIO UX to display them on the move.

We’ve covered OBD hacks too numerous to mention over the years, but perhaps you’d like to read our history of the standard.

At 71,572 KM, You Won’t Beat This LoRa Record

พฤ, 02/22/2018 - 16:00

A distance record for LoRa transmission has been set that you probably won’t be able to beat. Pack up your gear and go home, nothing more to achieve here. At a superficial reading having a figure of 71,572 km (44,473 miles) seems an impossible figure for one of the little LoRa radio modules many of us have hooked up to our microcontrollers, but the story isn’t quite what you’d expect and contains within it some extremely interesting use of technology.

So the folks at Outernet have sent data over LoRa for that incredible distance, but they did so not through the little ISM band modules we’re used to but over a suitably powerful Ku-band uplink to a geostationary satellite. They are also not using the LoRaWAN protocols of the earthbound systems, but simply the LoRa modulation scheme. So it’s not directly comparable to terrestrial records such as the 702 km we reported on last year, and they are the first to admit that.

Where their achievement becomes especially interesting though is in their choice of receiver. We are all used to Ku-band receivers, you may even have one on your house somewhere for satellite TV. It will probably involve a parabolic dish with a narrow beam width and an LNB whose horn antenna is placed at its focus. It would have required some skill and effort to set up, because it has to be pointed very carefully at the satellite’s position in the sky. Outernet’s mission of delivering an information service with the lowest possible barrier to entry precludes the extra expense of shipping a dish and providing trained staff to align it, so they take a very different approach. Their receiver uses either an LNB horn or a small patch antenna pointing at the satellite, with none of the dishes or phased arrays you might be used to in a Ku-band installation.

You might wonder how such a receiver could possibly work with such a meagre antenna, but the secret lies in LoRa’s relatively tiny bandwidth as well as the resistance to co-channel interference that is a built-in feature of the LoRa modulation scheme. Even though the receiver will be illuminated by multiple satellites at once it is able to retrieve the signal and achieve a 30 kb/s data rate that they hope with technical refinements to increase to 100 kb/s. This rate will be enough over which to push an SD video stream to name just one of the several examples of the type of content they hope to deliver.

It’s likely that the average Hackaday reader will not be hiring satellite uplink time upon which to place their LoRa traffic. But this story does provide a demonstration of LoRa’s impressive capabilities, and will make us look upon our humble LNBs with new eyes.

Via ABOpen.

Relive Radio Shack’s Glory Days by Getting Goofy

พฤ, 02/22/2018 - 13:00

The Golden Age of Radio Shack was probably sometime in the mid-1970s, a time when you could just pop into the local store and pay 49 cents for the resistors you needed to complete a project. Radio Shack was the place to go for everything from hi-fi systems to CB radios, and for many of us, being inside one was very much a kid in a candy store scenario.

That’s not to say that Radio Shack was perfect, but one thing it did very well was the education and grooming of the next generation of electronics hobbyists, primarily through their “Science Fair” brand. Some of us will recall the P-Box kits from that line, complete projects with all the parts and instructions in a plastic box with a perfboard top. These kits were endlessly entertaining and educational, and now [NetZener] has recreated the classic neon “Goofy Light” P-Box project.

As it was back in the day, the Goofy Light is almost entirely useless except for learning about DC-DC converters, multivibrators, RC timing circuits, and the weird world of negative resistance. But by using the original Science Fair instructions, compiling a BOM that can be filled from Mouser or Digikey, and making up a reasonable facsimile of the original P-Box chassis, [NetZener] has done a service to anyone looking for a little dose of nostalgia.

It would be interesting if someone brought back the P-Box experience as a commercial venture, offering a range of kits with circuits like the originals. If that happens, maybe some of the offerings will be based on that other classic from Radio Shack’s heyday.

Retrocomputing for the Forgotten

พฤ, 02/22/2018 - 10:00

The world runs on marketing hype. Remember the public relations swirl around the Segway? Before it rolled out we were led to believe it was going to be remembered as fire, the wheel, and Segway. Didn’t really happen. Microsoft and IBM had done something similar with OS/2, which you may not even remember as the once heir-apparent to MS-DOS. OS/2 was to be the operating system that would cure all the problems with MS-DOS just as IBM’s new Microchannel Architecture would cure all the problems surrounding the ISA bus (primarily that they couldn’t stop people from cloning it). What happened? OS/2 died a slow agonizing death after the Microsoft/IBM divorce. But for whatever reason [Ryan C. Gordon] decided to write a Linux emulation layer for OS/2 call 2ine (twine).

We like retrocomputing projects even if they aren’t very practical, and this one qualifies. The best analog for 2ine is it is Wine for OS/2, which probably has something to do with the choice of name. You might be ready to click away since you probably don’t have any OS/2 programs you want to run, but wait! The good news is that the post has a lot of technical detail about how Linux and OS/2 programs load and execute. For that reason alone, the post is well worth a read.

[Ryan] had been working on Unreal Tournament 2004 and saw a product called [Pixomatic]. Under Linux, Pixomatic actually loads a Windows DLL to do some work. This led him to dig into how the loaders worked and — of course — this is not unlike how Wine can load Windows binaries and provide them Windows API services that really do things in the Linux way. This led to a lot of interesting projects he mentions in passing, including one to load a shared library from memory instead of a file.

So recently in a fit of boredom, he’s started loading OS/2 programs and has had some success. This took some research on the OS/2 executable format and a lot of exploration of OS/2 strange memory model, exacerbated by the shift from 16-bit OS/2 to 32-bit OS/2. The big pay off is how he found how Wine and dosemu can cobble up the 32-bit Linux environment to run 16-bit code.

There’s more, but just go read the post. The detail is impressive and although it isn’t running anything practical yet, it does work and the technical detective work behind it makes for a great read.

As for period reproductions, we’d much rather do hardware and simulate a Z80 or just about anything else. Still, OS/2 is part of the PC’s history, and the lessons you can glean from this transcend the actually usefulness — or lack thereof — of running OS/2 binaries.

Linux Adds CH341 GPIO

พฤ, 02/22/2018 - 07:00

There was a time when USB to serial hardware meant one company: FTDI. But today there are quite a few to choose from and one of the most common ones is the WCH CH341. There’s been support for these chips in Linux for a while, but only for use as a communication port. The device actually has RS232, I2C, SPI, and 8 general purpose I/O (GPIO) pins. [ZooBaB] took an out-of-tree driver that exposes the GPIO, and got it working with some frightening-looking CH341 boards.

He had to make a slight mod to the driver to get six GPIOs in /sys/class/gpio. Once there though, it is easy to manipulate the pins using a shell script or anything that can write to the virtual files corresponding to the GPIO pins.

For example, he did a speed test that was this simple:

#!/bin/bash x=100000 while ((x--)); do i=$((i+1)) echo 0 > /sys/class/gpio/gpio1/value echo 1 > /sys/class/gpio/gpio1/value done

He got about 2.2 kHz out of the output pin, and although he didn’t say the exact hardware configuration it gives you some idea about the possible speed.

There are some other examples, and a look at several inexpensive boards that expose the I/O pins. There’s also some discussion of some mods of those boards.

The ability to share and hack drivers is one of the things that makes Linux so great for hackers. Your Linux system probably has all the tools you need and, if not, they are a package manager command away. Even if you aren’t comfortable building a whole driver, patching one like [ZooBab] did is very doable.

Of course, there are faster ways to drive I/O. We looked at the details of the CH340 and CH341 way back in 2014.

Vintage Sewing Machine to Computerized Embroidery Machine

พฤ, 02/22/2018 - 04:00

It is February of 2018. Do you remember what you were doing in December of 2012? If you’re [juppiter], you were starting your CNC Embroidery Machine which would not be completed for more than half of a decade. Results speak for themselves, but this may be the last time we see a first-generation Raspberry Pi without calling it retro.

The heart of the build is a vintage Borletti sewing machine, and if you like machinery porn, you’re going to enjoy the video after the break. The brains of the machine are an Arduino UNO filled with GRBL goodness and the Pi which is running CherryPy. For muscles, there are three Postep25 stepper drivers and corresponding NEMA 17 stepper motors.

The first two axes are for an X-Y table responsible for moving the fabric through the machine. The third axis is the flywheel. The rigidity of the fabric frame comes from its brass construction which may have been soldered at the kitchen table and supervised by a big orange cat. A rigid frame is the first ingredient in reliable results, but belt tension can’t be understated. His belt tensioning trick may not be new to you, but it was new to some of us. Italian translation may be necessary.

The skills brought together for this build were vast. There was structural soldering, part machining, a microcontroller, and motion control. The first time we heard from [juppiter] was December 2012, and it was the result of a Portable CNC Mill which likely had some influence on this creation. Between then, he also shared his quarter-gobbling arcade cabinet with us.

MIT Extracts Power from Temperature Fluctuations

พฤ, 02/22/2018 - 02:30

As a civilization, we are proficient with the “boil water, make steam” method of turning various heat sources into power we feed our infrastructure. Away from that, we can use solar panels. But what if direct sunlight is not available either? A team at MIT demonstrated how to extract power from daily temperature swings.

Running on temperature difference between day and night is arguably a very indirect form of solar energy. It could work in shaded areas where solar panels would not. But lacking a time machine, or an equally improbable portal to the other side of the planet, how did they bring thermal gradient between day and night together?

This team called their invention a “thermal resonator”: an assembly of materials tuned to work over a specific range of time and temperature. When successful, the device output temperature is out-of-phase with its input: cold in one section while the other is hot, and vice versa. Energy can then be harvested from the temperature differential via “conventional thermoelectrics”.

Power output of the initial prototype is modest. Given a 10 degree Celsius daily swing in temperature, it could produce 1.3 milliwatt at maximum potential of 350 millivolt. While the Hackaday coin-cell challenge participants and other pioneers of low-power electronics could probably do something interesting, the rest of us will have to wait for thermal resonator designs to evolve and improve on its way out of the lab.

[via Engadget]

Retrotechtacular: The Best Jeep Commercial Ever

พฤ, 02/22/2018 - 01:01

How often do we find ourselves thankful for advertising? When it comes to Hackaday’s Retrotechtacular column it’s actually quite often since it snapshots a moment in culture and technology. Today’s offering is a shining example, where we get a great look into vehicular utility of the day that is rarely seen in our modern lives.

The origin story of the Jeep is of course its prominence in World War II when more than half a million were produced. GIs who drove the vehicles constantly during the war greatly appreciated the reliability and versatility and wanted one for their own when returning home and a market rose up to satisfy that need. The modern equivalent would be the Hummer fad that started in the 1990’s. Humvee, the early ancestor of the Hummer, replaced the Jeep in the US military in the 1980’s and a version called Hummer entered the consumer market in ’92. But that was more of a comfort-meets-icon proposition, where the Jeep of the 1950’s (seen in the commercial below) delivered — even over delivered — on a promise of utility.

In this ad, the case is made for Jeep as farm implement, acting as plow, mower, even post hole digger. As a firefighting implement the announcer boasts that “One man with a Jeep can do the work of 100 men with shovels” by cutting fire breaks into the soil. It’s sold as the workhorse of cemeteries, ranches, county service crews, and anything else their marketing gurus could write into copy. We think the metrics are dubious but certainly the inexpensive build, versatile nature, and need for power equipment across the countryside brought these Jeeps into widespread rural and industrial service in myriad roles.

Power take off driving shaft to power circular saw. You can also see the hydraulics that lift and lower the saw.

What makes most of this possible is the existence of a power take-off (PTO). This is a mechanical connection from the engine of the vehicle to external components that can be switched out. Once connected, the speed of the engine can be controlled to adjust the power take-off operation. In conjunction with a hydraulic system that can lift and lower the implement, it becomes a remarkably versatile system. We begin to wonder the American vernacular includes the saying “it’s like the Swiss Army knife of…” rather than calling everything that’s insanely useful a Jeep.

Connect a pump to the PTO and you have a fire-fighting Jeep. Connect a generator and you can drive electric tools like the chainsaw used to cut down a tree in the video and to power an arc welder. There’s a gnarly-looking circular saw blade, and you’re going to spill your coffee when you get to the “Jeep-a-trench”. That’s right, a trenching attachment gives the vehicle’s suspension a rough workout. It boasts the ability to dig down six feet and complete the footings for an ordinary house in just three hours.

Willy’s MB, the company behind the Jeep must have employed a crew of hackers. What a blast it would have been to be in the research and development sessions to come up with 1,001 more uses for the equipment. The company has a bit of Jeep history you can peruse, but we’d really love to hear about the addon equipment ideas that didn’t make the cut. Are there any readers who have some stories along these lines? Let us know in the comments below.

Friday Hack Chat: Trusting The Autorouter

พฤ, 02/22/2018 - 00:15

Ah, the autorouter. Inside every PCB design tool, there’s a function called the ‘autorouter’. This function, when used correctly, is able to automagically lay traces between pads, producing a perfect board in under a minute. The trouble is, no one uses it. We have been told not to trust the autorouters and we hear a lot of other dire warnings about it. The autorouter never works. The autorouter will put traces everywhere. The autorouter doesn’t consider floorplanning, and sometimes you’re going to get traces that go right through the edge of your board. Is avoiding the autorouter sound advice?

For this week’s Hack Chat, we’re talking about trusting the autorouter. The autorouter is just a tool, and like any tool, it will do exactly what you tell it. The problem, therefore, is being smart enough to use the autorouter.

Our guest for this week’s Hack Chat is Ben Jordan, Director of Community Tools and Content at Altium. Ben is a Computer Systems engineer, with 25 years experience in board-level hardware and embedded systems design. He picked up a soldering iron at 8, and wrote some assembly at 12. He’s also an expert at using an autorouter successfully.

In this Hack Chat, we’re going to talk to Ben about Altium, Circuit Maker, and how to get the best performance out of an autorouter. How do you set the autorouter up? How do you test your settings? What, actually, is the technology and math that goes into an autorouter? What is the best way to design a multilayer board? How do you do multiboard designs? And what’s the deal with mixed signals?

Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. This Hack Chat is going down Friday, February 23rd at noon, Pacific time. Want to know what time this is happening in your neck of the woods? Here, look at the neat time zone converter thingy.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io.

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.

3D Printed Skateboard Mount for Bikes

พุธ, 02/21/2018 - 23:30

[Matt Obal] had a problem. The local skatepark was too far to skateboard, but close enough to bike. Carrying a skateboard on a bicycle is a rather awkward (and unsafe) maneuver. [Matt’s] answer to the problem is Truck Stop, a bicycle mounted skateboard carrier he developed and is manufacturing himself.

[Matt’s] work on Truck Stop began about a year ago, with his purchase of a 3D printer. He designed a seat back mounted device that secures the skateboard by wedging between the truck and the board itself. The design is printed in PLA and is hollow. Truck Stop’s strength comes from being filled with resin and fiberglass cloth.

If you’ve worked with resin, you probably know that some formulas get hot while they harden. This caused a few melted prints until [Matt] figured out that a dunk in cold water at the right time would allow the resin to complete it’s hardening process while keeping the heat below the melting temperature of PLA. He’s since switched to a different resin formula that generates less heat.

[Matt] is selling the Truck Stop at his website, and spent quite a bit of time working on a silicon mold so he could cast as many mounts as he wanted. The problem was fiberglass poking through the final cast part. In the end, he decided to stick with the resin filled PLA of his prototypes.

The King of Machine Tools

พุธ, 02/21/2018 - 22:01

The lathe is known as the King of Machine Tools for a reason. There are very few things that you can’t make with one. In fact, people love to utter the old saw that the lathe is the only machine tool that can make itself. While catchy, I think that’s a bit disingenuous. It’s more accurate to say that there are parts in all machine tools that (arguably) only a lathe can make. In that sense, the lathe is the most “fundamental” machine tool. Before you harbor dreams of self-replication, however, know that most of an early lathe would be made by hand scraping the required flat surfaces. So no, a lathe can’t make itself really, but a lathe and a skilled craftsperson with a hand-scraper sure can. In fact, if you’ve read the The Metal Lathe by David J. Gingery, you know that a lathe is instrumental in building itself while you’re still working on it.

We’re taking trip through the machining world with this series of articles. In the previous article we went over the history of machine tools. Let’s cut to the modern chase now and help some interested folks get into the world of hobby machining, shall we? As we saw last time, the first machine tools were lathes, and that’s also where you should start.

Precision Inception

With that bit of pedantry out of the way, let’s talk about why lathes are fundamental. Remember how I said that machine tools cleverly create parts that have greater precision than they themselves do? The lathe is the primary example of that.

First and foremost, the machine spins the work while the cutting tool remains stationary. This may seem arbitrary, but it most certainly is not. The earliest lathes held the workpiece between two sharp points. This is a clever way to achieve extremely high precision on one axis. So much so that turning “between centers” is still the go-to technique today when maximum precision is needed. Two points form a straight line, and by supporting the work this way, we eliminate all sources of “run out” or imprecision in the drive mechanism. This in turn reduces the precision problem to figuring out how to move the tool back and forth while maintaining a well-controlled distance to the work. This is a much easier problem to solve than any other mechanical geometry a machine tool might use, and thus why lathes are king.

The lathe is the place to start for getting into machining as a hobby because it teaches you the fundamentals that apply to all machine tools, while also being the most generally useful. The deeper you get into lathe work, the more you realize how little there is that it can’t make. Most other machine tools exist not to do things the lathe can’t, but rather to make those operations simpler to set up or faster to perform.

Sizing Up Your First Lathe

Okay, so you’ve made the wise decision to buy a lathe. Where should you start? The first decision to make is size. The rule of thumb among Crusty Old Machinists is that you must buy the largest machine you have space for. The saying goes that you can make small things on a large lathe, but you can’t make large things on a small lathe. Like most old sayings, it’s only kinda true. Using a machine suited to the size of work you’re doing makes sense. If you want to make clocks, RC cars, or models, get a small bench-top machine. If you want to blueprint an engine for a racecar or repair the town’s historic steam locomotive, get a large floor-standing machine.

Lathes are measured in “swing” and bed length. A designation like “7×20″ means something 7″ in diameter can be swung around without hitting the bed, and the bed itself is 20″ long. Like most numbers applied to consumer products, these are both misleading. While a 7″ object may technically fit, the machine probably doesn’t have the horsepower or toolpost reach to actually work on something at that limit. Similarly, that 20” bed length quickly gets eaten up by the tailstock, drills, and other tooling that need to be inside your work envelope. In that sense, the old saying is true — get a machine that is as big as you think you can fit within the category of work you want to do.

I’ll leave you now to think about how big your machine should be. Next time we’ll get into what to look for in a machine, how to buy one, where to put it, and so forth. Stay tuned!

Learning The 555 From The Inside

พุธ, 02/21/2018 - 19:00

One way to understand how the 555 timer works and how to use it is by learning what the pins mean and what to connect to them. A far more enjoyable, and arguably a more useful way to learn is by looking at what’s going on inside during each of its modes of operation. [Dejan Nedelkovski] has put together just such a video where he walks through how the 555 timer IC works from the inside.

We especially like how he immediately removes the fear factor by first showing a schematic with all the individual components but then grouping them into what they make up: two comparators, a voltage divider, a flip-flop, a discharge transistor, and an output stage. Having lifted the internals to a higher level, he then walks through examples, with external components attached, for each of the three operating modes: bistable, monostable and astable. If you’re already familiar with the 555 then you’ll enjoy the trip down memory lane. If you’re not familiar with it, then you soon will be. Check out his video below.

This isn’t the only time we’ve toyed with the guts of this wonderful chip. A few years ago we were all delighted with this mega-sized discrete 555 kit and a little more recently, this teardown of the actual chip.

An Especially Tiny And Perfectly Formed FM Bug

พุธ, 02/21/2018 - 16:00

It used to be something of an electronic rite of passage, the construction of an FM bug. Many of us will have taken a single RF transistor and a tiny coil of stiff wire, and with the help of a few passive components made an oscillator somewhere in the FM broadcast band. Connect up a microphone and you were a broadcaster, a prankster, and probably set upon a course towards a life in electronics. Back in the day such a bug might have been made from components robbed from a piece of scrap consumer gear such as a TV or VCR, and perhaps constructed spider-web style on a bit of tinplate. It wouldn’t have been stable and it certainly wouldn’t have been legal in many countries but the sense of achievement was huge.

As you might expect with a few decades of technological advancement, the science of FM bugs has moved with the times. Though you can still buy the single transistor bugs as kits there is a whole range of fancy chips designed for MP3 players that provide stable miniature transmitters with useful features such as stereo encoders. That’s not to say there isn’t scope for an updated simple bug too though, and here [James] delivers the goods with his tiny FM transmitter.

Gone is the transistor, and in its place is a MAX2606 voltage-controlled oscillator. The on-chip varicap and buffer provided by this device alleviate some of the stability issues suffered by the transistor circuits, and to improve performance further he’s added an AP2210 low-dropout regulator to catch any power-related drift. If it were ours we’d put in some kind of output network to use both sides of the differential output, but his single-ended solution at least offers simplicity. The whole is put on a board so tiny as to be dwarfed by a CR2032 cell, and we can see that a bug that size could provide hours of fun.

This may be a small and simple project, but it has found its way here for being an extremely well-executed one. It’s by no means the first FM bug we’ve shown you here, just a few are this one using scavenged SMD cellphone parts, or this more traditional circuit built on a piece of stripboard.

DIY Peristaltic Pump Keeps the Booze Flowing

พุธ, 02/21/2018 - 13:00

A few months ago we showed you a bar bot built by [GreatScott] that uses peristaltic pumps to food-safely move the various spirits and mixers around behind the curtain. The bar bot uses three of them, and at $30 each for pumps with decent flow rate, they added a lot to the parts bill. These pumps are pretty much the ideal choice for a bar bot, so what do you do? [GreatScott] decided to see if it was worth it to make them instead.

Peristaltic pumps are simple devices that pump liquids without touching them. A motor turns a set of rollers that push a flexible tube against a wall. As the motor turns, the rollers move liquid through the tube by squeezing it flat from the outside in turns. Typically, the more you pay for an off-the-shelf peristaltic, the higher the flow rate.

[GreatScott] figured it was cheaper to buy the motor and the control circuitry. He chose a NEMA-17 for their reputation and ubiquity and a DRV8825 controller to go with it. The pump is driven by an Arduino Nano and a pot controls the RPM. After trying to design the mechanical assembly from scratch, he found [Ralf]’s pump model on Thingiverse and modified it to fit a NEMA-17.

The verdict? DIY all the way, assuming you can print the parts. [GreatScott] was trying to beat the purchased pumps’ flow rate of 100mL/minute and ended up with 200mL/minute from his DIY pump. Squeeze past the break for the build video and demonstration.

Is there a bar bot build on your list? No? Is it because you’re more of a single-malt scotch guy? Build a peristaltic pachyderm to pour your potion.

Dungeons and Dragons TV Tabletop!

พุธ, 02/21/2018 - 10:00

With little more than pen, paper, dice, and imagination, a group of friends can transport themselves to another plane for shenanigans involving dungeons and/or dragons. An avid fan of D&D and a budding woodworker, Imgurian [CapnJackHarkness] decided to build gaming table with an inlaid TV for their inaugural project.

The tabletop is a 4’x4′ sheet of plywood, reinforced from underneath and cut out to accommodate a support box for the TV. Each leg ended up being four pieces of 1’x4′ wood, laminated together with a channel cut into one for the table’s power cable. An outer ledge has dice trays — if they’re even needed in today’s world — ready for all those nat 20s, cupholders because nobody likes crying over spilled drinks, and electrical outlets to keep devices charged. Foam squares cover the tabletop which can be easily removed and washed if needed — but more on that in a second. [CapnJackHarkness] painted the table as the wood rebuffed many attempts at staining, but they’re happy with how it turned out.

[CapnJackHarkness] based their build on a table made by Gaminggeek, adapting it to their space and needs. The main difference? This wasn’t exactly ‘cheap;’ between needing to purchase tools and a 39″ TV, their cost was around $1,000 — the poplar alone coming in between $200-$400. Additionally, those foam pads have been a functional nuisance so far, so they’re planning on replacing them with speed cloth or felt down the line.

While the game space displayed on the TV is handled by roll20, that doesn’t mean [CapnJackHarkness] or their friends can’t add a few extra props to their sessions.

[Via /r/gaming]

Cross-Brand Adapter Makes for Blended Battery Family

พุธ, 02/21/2018 - 07:00

Even though he’s a faithful DeWalt cordless tool guy, [Richard Day] admits to a wandering eye in the tool aisle, looking at the Ryobi offerings with impure thoughts. Could he stay true to his brand and stick with his huge stock of yellow tools and batteries, or would he succumb to temptation and add another set of batteries and chargers so he could have access to a few specialty lime green tools?

Luckily, we live in the future, so there’s a third way — building a cross-brand battery adapter that lets him power Ryobi tools with his DeWalt batteries. [Richard]’s solution is a pure hack, as in physically hacking battery packs and forcing them to work and play well together. Mechanically, this was pretty easy — a dead Ryobi pack from the recycling bin at Home Depot was stripped down for its case, which was glued to a Dewalt 20-v to 18-v battery adapter. The tricky part came from dealing with the battery control electronics. Luckily, the donor DeWalt line has that circuitry in the adapter, while Ryobi puts it in the battery. That meant simply transplanting the PCB from the adapter to the Ryobi battery shell would be enough. The video below shows the process and the results — Ryobi tools happily clicking away on DeWalt batteries.

While [Richard] took a somewhat brute-force approach here, we imagine 3D-printed parts might make for a more elegant solution and offer other brand permutations. After all, printing an adapter should be easier than whipping up a cordless battery pack de novo.