A Queen Mystery: The Legend Of The Deacy Amp

May 8, 2017 by 56 Comments

It sounds like a scene from a movie. A dark night in London, 1972. A young man walks alone, heading home after a long night of practicing with his band. His heavy Fender bass slung over his back, he’s weary but excited about the future. As he passes a skip (dumpster for the Americans out there), a splash of color catches his attention. Wires – not building power wires, but thinner gauge electronics connection wire. A tinkerer studying for his Electrical Engineering degree, the man had to investigate. What he found would become rock and roll history, and the seed of mystery stretching over 40 years.

The man was John Deacon, and he had recently signed on as bassist for a band named Queen. Reaching into the skip, he found the wires attached to a circuit board. The circuit looked to be an amplifier. Probably from a transistor radio or a tape player. Queen hadn’t made it big yet, so all the members were struggling to get by in London.

Deacon took the board back home and examined it closer. It looked like it would make a good practice amplifier for his guitar. He fit the amp inside an old bookshelf speaker, added a ¼ “ jack for input, and closed up the case. A volume control potentiometer dangled out the back of the case. Power came from a 9-volt battery outside the amp case. No, not a tiny transistor battery; this was a rather beefy PP-9 pack, commonly used in radios back then. The amp sounded best cranked all the way up, so eventually, even the volume control was removed. John liked the knobless simplicity – just plug in the guitar and play. No controls to fiddle with.

And just like that, The Deacy amp was born.

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Powerful, Professional Brushless Motor From 3D-Printed Parts

May 8, 2017 by 23 Comments

Not satisfied with the specs of off-the-shelf brushless DC motors? Looking to up the difficulty level on your next quadcopter build? Or perhaps you just define “DIY” as rigorously as possible? If any of those are true, you might want to check out this hand-wound, 3D-printed brushless DC motor.

There might be another reason behind [Christoph Laimer]’s build — moar power! The BLDC he created looks more like a ceiling fan motor than something you’d see on a quad, and clocks in at a respectable 600 watts and 80% efficiency. The motor uses 3D-printed parts for the rotor, stator, and stator mount. The rotor is printed from PETG, while the stator uses magnetic PLA to increase the flux and handle the heat better. Neodymium magnets are slipped into slots in the rotor in a Halbach arrangement to increase the magnetic field inside the rotor. Balancing the weights and strengths of the magnets and winding the stator seem like tedious jobs, but [Cristoph] provides detailed instructions that should see you through these processes. The videos below shows an impressive test of the motor. Even limited to 8,000 rpm from its theoretical 15k max, it’s a bit scary.

Looking for a more educational that practical BLDC build? Try one cobbled from PVC pipes, or even this see-through scrap-bin BLDC.

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A Digital Tacho For A Harley

May 8, 2017 by 35 Comments

If you are a lover of motorcycling, you’ll probably fit into one or other of the distinct groups of riders. Maybe you’re a sportsbike lover always trying to get your knee down, a supermotard who gets their knee down without trying, a trailie rider for whom tarmac is an annoyance between real rides, or a classic bike enthusiast who spends more time in the workshop than riding.

[Xavier Morales] is none of these, for he cruises the roads of his native Catalonia on a Harley-Davidson Sportster. If you’re familiar with Harleys only from popular culture, or you’re a sportsbike rider who derides them for anachronistic handling and brakes, it’s worth taking a look at a modern Harley from a technical standpoint. Despite styling and brand ethos that evokes another era with the trademark large V-twin engine that looks to the untrained eye the same as it did decades ago, today’s Harley is a very modern machine, and much more capable than the sneering sportsbiker would give it credit for.

There is one area though in which [Xavier]’s Harley was sorely lacking. Its single instrument was a speedometer, it had no rev counter. You might think this would be less of an issue with the lower-revving Harley engine than it would be with a Japanese sportsbike that exists in a hail of revs, but it was annoying enough to him that he built his own tachometer. His write-up of the project is both lengthy and fascinating, and well worth a read.

The Sportster’s data bus follows an established but obsolete standard, SAE J1850 VPW. Since driver chips for this bus are out of production, he had to create his own using a transistor and a couple of resistors. Once he has the data he feeds it to a PIC 18F2553 which in turn runs a display driver chip controlling a brace of 7-segment LEDs. There are also a set of LEDs to indicate gear changes. The whole is installed in a 3D-printed housing alongside the original speedometer, behind the glass from another dial. As a result it looks as though the bike was always meant to be a two-clock design, with a professional appearance.

If you’d like to see it in action, he’s posted a few videos, and we’ve put one below the break. The beautiful Catalan scenery and the mountain twisties look very inviting.

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“Look Ma, No Gyros!”: A Self-Balancing Mechanical Velociraptor

May 7, 2017 by 22 Comments

You’ve got to walk before you can run, right? Perhaps not, if this bipedal dino-like running robot is any indication.

Officially dubbed a “Planar Elliptical Runner,” the bot is a test platform for bipedal locomotion from the Institute for Human and Machine Cognition. Taking inspiration from the gait of an ostrich — we think it looks more like a T. rex or velociraptor, but same difference — [Jerry Pratt]’s team at IHMC have built something pretty remarkable. Contrary to all the bipedal and quadrupedal robots we’ve seen, like Boston Dynamics’ Big Dog and PETMAN, which all fairly bristle with sensors and actuators, the PER is very stripped down.

A single motor runs the entire drive chain using linkages that will look familiar to anyone who has taken an elliptical trainer apart, and there’s not a computer or sensor on board. The PER keeps its balance by what the team calls “reactive resilience”: torsion springs between the drive sprocket and cranks automatically modulate the power to both the landing leg and the swing leg to confer stability during a run. The video below shows this well if you single-frame it starting at 2:03; note the variable angles of the crank arms as the robot works through its stride.

The treadmill tests are constrained by a couple of plastic sheets, but the next version will run free. It’s not clear yet how directional control will be achieved, not is it obvious how the PER will be able to stop running and keep its balance. But it’s an interesting advance in locomotion and we look forward to seeing what IHMC’s next trick will be.

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Anatomically Correct Plotter Avoids Back Scratch Fever

May 7, 2017 by 15 Comments

Everybody needs somebody sometimes, even if it’s just for when your back itches. But directing your itchy interlocutor to the correct spot can be a spatial relations challenge: “Right in the middle… no, down a bit… left… no, the other left! Harder! Wait, not that hard!” Why bother with all that messy interpersonal communication and human contact when you can build an automated, precision-guided back scratcher?

[VijeMiller] has aluminum extrusion tastes on a cardboard budget, but don’t let that put you off this clever build. The idea is pretty simple: a two-axis plotter that moves a rotary-action business end to any point within a V-shaped work envelope. The Arduino in the base talks to a smartphone app that lets you point to exactly the spot in need of attention on what for most of us would be an incredibly optimistic photorealistic map of the dorsal aspect of the body (mildly NSFW photo in the link above dips below the posterior border). Point, click, sweet relief.

The video below shows the rig in action, along with the Thespian skills we’ve come to know and love from [VijeMiller] with such classics as the fake floating 19th green, the no-idling-while-texting alert, and the more recent ker-sploosh fighting foam filled toilet. It does seem like he changed his name from [TVMiller] somewhere along the line, but he can’t throw us off the trail that easily.

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Hackaday Links: May 7, 2017

May 7, 2017 by 19 Comments

The International Journal of PoC||GTFO is the hacker quarterly we all deserve. It’s Pastor Manul Laphroaig’s publication featuring crazy exploits and builds and neat woodcut illustrations. It’s going to be a freakin’ dead tree book published by No Starch Press. The word on the street is this is a literal bible. No, really. No Starch found a place that publishes (manufactures?) bibles, and they sent over the PDFs. There will probably be a Hackaday review of this book, but since all the content is freely available online, this review will literally only be judging a book by its cover.

Hoverboards are more innovative than a selfie stick. The snuggie is an innovative product. The iPhone came before greek yogurt. These are the findings of an online consumer research poll being held by CB Insights. As of this writing (and it might be updated by the time this is published), the bracket for the ‘Most Innovative Consumer Product Since The iPhone’ is down to two competitors — the Tesla Model S and the Raspberry Pi. That’s more opinion than anything, but check out the bracket. The Amazon Echo is more innovative than the ‘desktop 3D printer’, which as we all know was invented by MakerBot. The Dollar Shave Club — otherwise known as giving away the razor and selling subscriptions for the blades — is innovative. Taco Bell didn’t make it past the first round. What the hell is going on here?

This robot plays tiddlywinks. What’s tiddlywinks? It’s that game where you put your hand down on a table and stab a knife between your fingers. It’s a test of fine motor skills and courage, or in this case, programming. This robot also plays tiddlywinks.

This is a Kickstarter for an FPGA’d ZX Spectrum. With the blessing of Sky UK — the owner of the Amstrad brand — this team is cloning the ZX Spectrum, adding HDMI and SD card storage, creating a new enclosure, and calling this project the Spectrum Next. It’s fully compatible with the original and future proofs the Speccy for another few decades.

The Internet of Things comes to alcohol. This vodka comes with a wrap-around LED display that apparently has Bluetooth and is programmable with an iPhone or Android device. Why does this exist? Because it’ll sell. [Bryan Williams] bought one of these bottles and sent this in on the tip line. He’s currently waiting for the batteries to die so he can bust out the Dremel. If anyone else out there wants to check this out, it’s $11 at Sam’s Club.

Need a Z80 C compiler? Here you go.

Clickspring, the guy who has put far, far too much effort into building a clock is now working on the Antikythera Mechanism. His latest video demonstrates how the main plates of the Antikythera mechanism come together. There’s some interesting stuff here, but we’re really waiting for the main gears.

YouTube is well known for the technical astuteness of its community and the fair and level-headed comment section. This, for a short time, was one of the top trending videos on YouTube. It’s ‘free energy’ from two power strips. All you need to do is coil the leads of the power strips around each other. Free intermittent energy for life!

Hackaday Prize Entry: RepRap Helios

May 7, 2017 by 30 Comments

Did you know that most of the current advances in desktop consumer 3D printing can be traced back to a rather unknown project started in 2005? This little-known RepRap project was dedicated to building Open Source hardware that was self-replicating by design. Before the great mindless consumerization of 3D printing began, the RepRap project was the greatest hope for Open Source hardware, and a sea change in what manufacturing could be.

While the RepRap project still lives on in companies like Lulzbot, Prusa, SeeMeCNC, and others, the vast community dedicated to creating Open Hardware for desktop manufacturing has somehow morphed into YouTube channels that feature 3D printed lions, 3D printed Pokemon, and a distinct lack of 3D printed combs. Still, though, there are people out there contributing to the effort.

[Nick Seward] is famous in the world of RepRap. He designed the RepRap GUS Simpson, an experimental 3D printer that is able to print all of its components inside its own build volume. The related LISA Simpson is an elegant machine that is unlike any other delta robot we’ve seen. He’s experimented with Core XZ machines for years now — a design that is only now appearing on AliBaba from random Chinese manufacturers. In short, [Nick Seward] is one of the greats of the RepRap project.

[Nick] is designing a new kind of RepRap, and he’s entered it in the Hackaday Prize. It can print most of its own component parts, it has an enormous build volume, and it’s unlike any 3D printer you’ve seen before. It’s a SCARA — not a, ‘robotic arm’ because SCARA is an acronym for Selective Compliance Articulated Robot Arm — that puts all the motors in the non-moving portion of the base. Its design is inspired by the RepRap Morgan, a printer whose designer won $20,000 in the GADA prize for being mostly self-replicating.

Improvements over the RepRap Morgan include a huge build volume (at least three 200x200mm squares can be placed in this printer’s build volume), a relatively fast print speed, high accuracy and precision, and auto bed leveling. Despite being more capable than some RepRap printers in some areas, the RepRap Helios should wind up being cheaper than most RepRap printers. It can also print most of its component parts, bringing us ever closer to a truly self-replicating machine.

You can check out a few of the videos of this printer in action below.

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