Red Bricks: Alphabet To Turn Off Revolv’s Lights

April 7, 2016 by Moritz Walter 65 Comments

Revolv, the bright red smart home hub famous for its abundance of radio modules, has finally been declared dead by its founders. After a series of acquisitions, Google’s parent company Alphabet has gained control over Revolv’s cloud service – and they are shutting it down.

Customers who bought into Revolv’s vision of a truly connected and automated smart home hub featuring 7 different physical radio modules to connect all their devices will soon become owners of significantly less useful, red bricks due to the complete shutdown of the service on May 15, 2016.
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A Look Into The Future Of Slicing

April 7, 2016 by Gerrit Coetzee 48 Comments

I’ve had a few conversations over the years with people about the future of 3D printing. One of the topics that arises frequently is the slicer, the software that turns a 3D model into paths for a 3D printer. I thought it would be a good idea to visualize what slicing, and by extension 3D printing, could be. I’ve always been a proponent of just building something, but sometimes it’s very easy to keep polishing the solution we have now rather than looking for and imagining the solutions that could be. Many of the things I’ll mention have been worked on or solved in one context or another, but not blended into a cohesive package.

I believe that fused deposition modelling (FDM), which is the cheapest and most common technology, can produce parts superior to other production techniques if treated properly. It should be possible to produce parts that handle forces in unique ways such that machining, molding, sintering, and other commonly implemented methods will have a hard time competing with in many applications.

Re-envisioning the slicer is no small task, so I’m going to tackle it in three articles. Part One, here, will cover the improvements yet to be had with the 2D and layer height model of slicing. It is the first and most accessible avenue for improvement in slicing technologies. It will require new software to be written but does not dramatically affect the current construction of 3D printers today. It should translate to every printer currently operating without even a firmware change.

Part Two will involve making mechanical changes to the printer: multiple materials, temperatures, and nozzle sizes at least. The slicer will need to work with the printer’s new capabilities to take full advantage of them.

Finally, in Part Three, we’ll consider adding more axes. A five axis 3D printer with advanced software, differing nozzle geometries, and multi material capabilities will be able to produce parts of significantly reduced weight while incorporating internal features exceeding our current composites in many ways. Five axis paths begin to allow for weaving techniques and advanced “grain” in the layers put down by the 3D printer.

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Hackaday World Create Day: April 23rd

April 7, 2016 by Mike Szczys 14 Comments

It’s time to get out and have some fun with other Hackaday people in your area and we have the perfect opportunity. Be part of Hackaday World Create Day on Saturday, April 23rd. This is all about meeting others for an afternoon of creativity. You might even find your engineering dream team! As part of World Create Day you’ll and brainstorm an amazing creation and connect with the people in your area that round out your own skills (electrical, mechanical, design, etc.).

This is the first ever worldwide event Hackaday has organized, and it’s made possible by all of the people who volunteered to organize a Hackaday Meetup in their area. We have heard from more than 100 of you so far and [Liz Krane] has done an amazing job following up with each organizer to get everything set up. You can still sign up to host (or co-host) and use the map to join a meetup already organized in your area.

We’re just getting started but the first added are in Ottawa Canada, Lagos Nigeria, Lynchburg, Virginia, and Puducherrry, India. We have more on the way in Malaysia, Greece, South Africa, India, Cyprus, New Zealand, France, Mexico, China, and many locations in the USA.

We’re sending out World Create Day sticker packs — created by [Joe Kim] and [Michael Guilfoil] — as fast as we can set up the Meetup pages. We will be on the lookout for Hackaday Meetups and World Create Day projects to feature right here on the Hackaday front page. Carve out 4/23 from your calendar and get excited, you don’t want to miss this!

Reverse-Engineering DebugWire

April 7, 2016 by Elliot Williams 12 Comments

Has this ever happened to you? You start out on a reverse-engineering project, start digging in, and then get stumped. Then you go looking on the Internet for help, and stumble across someone who’s already done exactly what you’re trying to do?

[Geekabit] wrote us with a version of this tale of woe. In his case, the protocol to be reversed was Atmel’s debugWire protocol for debugging on low-pin-count parts. There are a number of websites claiming it’s “secret” or whatever, but it actually looks like it’s just poorly documented. Anyway, [RikusW] seems to have captured all of the signals way back in 2011. Good job!

The best part of [geekabit]’s story is that he had created the Wikipedia page on debugWire himself to inspire collaboration on reverse-engineering the protocol, and someone linked in [RiskusW]’s work. When [geekabit] picked up the problem again a bit later, he did a bit of web research and found it solved — on the page that he started.

Maybe it’s not a tale of woe after all, but a tale of unintentional collaboration. Anyway, it serves as a reminder that if you’re interested in the destination more than the voyage of discovery, it never hurts to do your research beforehand. And now we all know about the low-level details of the debugWire protocol. Anyone written up a driver yet?

Thanks [geekabit] for the tip and the story! Image from ATmega32-AVR, which explains nicely how to use the Dragon in debugWire mode.

Getting Serious About Crystal Radios

April 7, 2016 by Gregory L. Charvat 45 Comments

The crystal radio is a timeless learning experience, often our first insight into how a radio works. For some of us that childhood fascination never dies. Take for example Jim Cushman, this guy loves to work on vintage scooters, motorcycles, and especially crystal radios (special thanks to fellow coil-winding enthusiast M. Rosen for providing the link). Digging more deeply we find an entire community devoted to crystal radio design. In this article we will get back to basics and study the fundamentals of radio receiver design.

How it works:

A crystal radio is basically a high Q resonator tied to an antenna and an envelope detector. These days the envelope detector is a point contact diode such as a 1N34 Germanium diode.

The resonant circuit passes a specific wavelength (or more specifically range of wavelengths depending on its Q). The diode detector provides the amplitude or envelope of the signal(s) within that wavelength. A high impedance or highly sensitive ear piece converts this envelope to an audible signal that you can listen to.

The neat thing about crystal radios is that no active RF amplification is used. The radio is powered by the incoming radio signal that it is tuned to. More sophisticated crystal sets might have more than one tuned stage, perhaps 3 or 4 to minimize receiver bandwidth for maximum sensitivity and selectivity.

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1921 Ner-A-Car Motorcycle Reborn With Epic Parts Remanufacture

April 7, 2016 by Jenny List 26 Comments

Most of the rusty parts you need to make a motorcycle.

Nobody ever dismantles a working motorcycle.

About ten years ago [Andy Pugh] took possession of a large box of rusty parts that formed most of what had once been a 1921 Ner-a-Car motorcycle. They languished for several years, until in 2014 he was spurred into action and returned to the bike. What followed was a two-year odyssey of rebuilding, restoration, and parts remanufacture, and since [Andy] is an engineer par excellence and an active member of the LinuxCNC community his blog posts on the subject should be a fascinating read for any hardware hacker with an interest in metalwork.

The Ner-a-Car. By Museumsfotografierer (Own work) [Public domain], via Wikimedia Commons

The Ner-a-Car represents one of those eccentric dead-ends in automotive history. Designed in 1918 by an American, [Carl Neracher], its name is a play on both its designer and its construction and it is unique in that its design is closer to the cars of the era than that of a motorcycle. It has a car-style chassis, an in-line engine, and it was the first motorcycle to be produced with hub-centre steering. The rider sits on it rather than astride it, feet-forward, and the car-style chassis gives it a very low centre of gravity. They were manufactured in slightly different versions in both the USA and the UK, and [Andy]’s machine is an early example from the British production line. Not many Ner-a-Cars have survived and parts availability is non-existent, so his work has also had the unusual effect of satisfying a significant portion of world demand for the parts-bin of an entire marque.

It’s usual for the first link in a Hackaday article to be to a page that encompasses the whole project. In this case when there is so much to see and the build is spread across twelve blog posts and nearly two years the link is to [Andy]’s first post in which he describes the project, sets to work on the chassis, and discovers the bent steering arm that probably caused the bike’s dismantling. He’s listed the posts in the column on the right-hand side of the blog, so you can follow his progress through the entire build. The work involved in remanufacturing the parts is to an extremely high standard, from machining press tools to reproduce 1920s footboard pressings through manufacturing authentic 1920s headlight switchgear and metal-spinning new aluminium headlight shells.

[Andy]’s most recent Ner-a-Car post details his trip to France on the completed bike, and tales of roadside repairs of a suddenly-not-working machine that should be familiar to any owner of a vintage internal combustion engine. But considering that the bike spent many decades as a pile of not much more than scrap metal the fact that it is now capable of a trip to France is nothing short of amazing.

This is the first rebuild of a vintage bike from a box of rusty parts we’ve featured here – indeed it could almost be a retrotechtacular piece in its detailed look at 1920s bike design. These pages have however seen many motorcycle related hacks over the years. We particularly like this from-scratch engine build and this gas-turbine bike, but it is the emergency motorcycle build in the desert from a Citroën 2CV car that has us most impressed. Please, ride safe, and keep them coming!

Error Correction Of 3D Printers

April 7, 2016 by Brian Benchoff 42 Comments

From the very first RepRaps to the newest and latest printers off the Makerbot assembly line, nearly every consumer 3D printer has one significant shortcoming: it cannot recover from missed steps, slipped belts, or overheating stepper drivers. Although these are fairly rare problems, it does happen and is purely a product of the ~~closed~~ open-loop control system used in 3D printer firmware.

[Chris Barr] has come up with a rather clever solution to this problem. He’s designed a system that will detect and correct problems with the mechanics of 3D printers. It’s technically not a closed-loop control system, but it does allow him to get the absolute position of a nozzle on the build plate, detects error states, and can automatically calculate the number of motor steps per millimeter. It’s also much simpler than other closed loop control systems we’ve seen in the past, requiring only a few bits and bobs attached to the axes and to the printer controller board.

[Chris]’ system uses a magnetic encoding strip, a single chip, and a little bit of support circuitry. It’s actually not that much different from the moving axis on a desktop inkjet printer. It’s not closed loop, though; the firmware hack is only a ‘basic error correction’ that moves the nozzle back to where it should be. Although this is somewhat of a kludge, it is much simpler than refactoring the entire printer firmware.

In the video below, [Chris] demonstrates his solution for error correcting the printer by jerking his axis around during a print. The nozzle miraculously returns to where it should be, producing a usable part.

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