Kinematic Mount For 3D Printer Bed Shows Practical Design

February 9, 2019 by Donald Papp 8 Comments

Aluminum bed with new kinematic mount and base on printer *Son of Megamax*, at the Milwaukee Makerspace

[Mark Rehorst] has been busy designing and building 3D printers, and Son of Megamax — one of his earlier builds — needed a bed heater replacement. He took the opportunity to add a Kelvin-type kinematic mount as well. The kinematic mount and base efficiently constrain the bed in a controlled way while allowing for thermal expansion, providing a stable platform that also allows for removal and repeatable re-positioning.

After a short discussion regarding the heater replacement, [Mark] explains the design and manufacture of his kinematic mount. Of particular note are the practical considerations of the design; [Mark] aimed to use square aluminum tubing as much as possible, with machining requirements that were easily done with the equipment he had available. Time is a resource after all, and design decisions that help one get something working quickly have a value all their own.

If you’re still a bit foggy on kinematic mounts and how they work, you’re not alone. Check out our coverage of this 3D-printed kinematic camera mount which should make the concept a bit clearer.

Voja Antonic: Designing The Cube

February 7, 2019 by Elliot Williams 6 Comments

Voja Antonic designed this fantastic retrocomputing badge for Hackaday Belgrade in 2018, and it was so much fun that we wanted to bring it stateside to the Supercon essentially unaltered. And that meant that Voja had some free time to devote to a new hardware giveaway: the Cube. So while his talk at Supercon in November was ostensibly about the badge, he just couldn’t help but tell us about his newer love, and some of the extremely clever features hidden within.

It’s funny how the hardware we design can sometimes reflect so much on the creator. Voja designed then-Yugoslavia’s first widely used home computer (and published the DIY plans in a magazine!). Thousands were built from their kits. The Galaksija was a Z80-based design with a custom BASIC that was just barely squeezed into the available 4K of ROM. So you shouldn’t be shocked that the retro-badge has a working keyboard and a nice BASIC on board.

But let’s jump ahead to the Cube, because that’s even more of a passion project. On the outside, they’re very simple devices, with only a USB port and a sweet diffused LED ring visible. Aesthetic? Minimalistic? Beautiful, honestly.
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Yell At Your Desk To Get Up In The Morning

February 5, 2019 by Lewin Day 4 Comments

Standing desks are great conversation starters in the office – whether you like it or not. How do you know someone’s got a standing desk? Don’t worry, they’ll tell you. Standing desks have their benefits, but for maximum flexibility, many people choose a desk that can raise and lower depending on their needs. [Wassim] had just such a desk, but found pushing the buttons too 20th century for his tastes. Naturally, Google Assistant integration was the key here.

[Wassim] started out intending to capture and then spoof the desk controller’s signals to the motors, before realising it was likely easier to simply spoof button presses instead. This was achieved through a handful of NPN transistors and an Onion Omega2+ microcontroller board. Then it was a simple case of coding the controller to press the various buttons in response to HTTP requests received over WiFi. Google Assistant integration was then handled with IFTTT, though [Wassim] also discusses the possibility of implementing the full Smart Home API.

It’s entertaining to watch [Wassim] issue commands and have the desk slowly rise in response. Of course, there are other approaches, like this sneaky use of PVC to hack the office furniture.

https://medium.com/@wassimchegham/hey-google-set-my-desk-to-standing-mode-b21dcc40d4b5

How To Deal With A Cheap Spectrum Analyzer

January 25, 2019 by Brian Benchoff 14 Comments

The Hackaday Superconference is all about showcasing the hardware heroics of the Hackaday community. We also have a peer-reviewed journal with the same goal, and for the 2018 Hackaday Superconference we got a taste of the first paper to make it into our fully Open Access Journal. It comes from Ted Yapo, it is indeed a tale of hardware heroics: what happens when you don’t want to spend sixty thousand dollars on a vector network analyzer?

Ted’s talk begins with a need for a network analyzer. These allow for RF measurements, but if you ever need one, be prepared: you can spend twenty thousand dollars on a used VNA. Around the time Ted’s project began, Rigol released their cheap spectrum analyzer, the DSA815. This thing only cost a thousand dollars. It was their first revision of the hardware, and it was only a scalar network analyzer. Being the first revision of the hardware, there were a few problems; there was leakage that would affect the measurement. The noise floor was higher than it should have been. These problems can be corrected, though, with a little bit of cunning from Ted:

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New Part Day: Small, Cheap, And Good LIDAR Modules

January 22, 2019 by Brian Benchoff 40 Comments

Fully autonomous cars might never pan out, but in the meantime we’re getting some really cool hardware designed for robotic taxicab prototypes. This is the Livox Mid-40 Lidar, a LIDAR module you can put on your car or drone. The best part? It only costs $600 USD.

The Livox Mid-40 and Mid-100 are two modules released by Livox, and the specs are impressive: the Mid-40 is able to scan 100,000 points per second at a detection range of 90 m with objects of 10% reflectivity. The Mid-40 sensor weighs 710 grams and comes in a package that is only 88 mm x 69 mm x 76 mm. The Mid-100 is basically the guts of three Mid-40 sensors stuffed into a larger enclosure, capable of 300,000 points per second, with a FOV of 98.4° by 38.4°.

The use case for these sensors is autonomous cars, (large) drones, search and rescue, and high-precision mapping. These units are a bit too large for a skateboard-sized DIY Robot Car, but a single Livox Mid-40 sensor, pointed downward on a reasonably sized drone could perform aerial mapping

There is one downside to the Livox Mid sensors — while you can buy them direct from the DJI web site, they’re not in production. These sensors are only, ‘Mass-Production ready’. This might be just Livox testing the market before ramping up production, a thinly-veiled press release, or something else entirely. That said, you can now buy a relatively cheap LIDAR module that’s actually really good.

Anatomy Of A Cloned Piece Of Hardware

January 21, 2019 by Jenny List 58 Comments

What would you think if you saw a bootleg of a product you design, manufacture, and sell pop up on eBay? For those of us who don’t make our livelihood this way, we might secretly hope our blinkenlight project ends up being so awesome that clones on AliExpress or TaoBao end up selling in the thousands . But of course anyone selling electronics as their business is going to be upset and wonder how this happened? It’s easy to fall into the trap of automatically assigning blame; if the legit boards were made in China would you assume that’s where the design was snagged to produce the bootlegs? There’s a saying about assumptions that applies to this tale.

Dave Curran from Tynemouth Software had one of his products cloned, and since he has been good enough to share all the details with us we’ve been able to take a look at the evidence. Dave’s detective work is top notch. What he found was surprising, his overseas manufacturer was blameless, and the bootleg board came from an entirely different source. Continue reading “Anatomy Of A Cloned Piece Of Hardware” →

You’ll Never See The End Of This Project

January 17, 2019 by Ted Yapo 26 Comments

…theoretically, anyway. When [Quinn] lucked into a bunch of 5 mm red LEDs and a tube of 74LS164 shift registers, a project sprang to mind: “The Forever Number,” a pseudo-random number generator with a period longer than the age of the universe. Of course, the components used will fail long before the sequence repeats, but who cares, this thing looks awesome!

Check out the gorgeous wire-wrapping job!

The core of the project is a 242-bit linear-feedback shift register (LFSR) constructed from (31) 74LS164’s. An XOR gate and inverter computes the next bit of the sequence by XNOR’ing two feedback bits taken from taps on the register, and this bit is then fed into bit zero. Depending on which feedback taps are chosen, the output sequence will repeat after some number of clock cycles, with special sets of feedback taps giving maximal lengths of 2^N – 1, where N is the register length. We’ll just note here that 2²⁴² is a BIG number.

The output of the LFSR is displayed on a 22×11 array of LEDs, with the resulting patterns reminiscent of retro supercomputers both real and fictional, such as the WOPR from the movie “War Games,” or the CM2 from Thinking Machines.

The clock for this massive shift register comes from – wait for it – a 555 timer. A potentiometer allows adjustment of the clock frequency from 0.5 to 20 Hz, and some extra gates from the XOR and inverter ICs serve as clock distribution buffers.

We especially love the construction on this one. Each connection is meticulously wire-wrapped point-to-point on the back of the board, a relic originally intended for an Intel SBC 80/10 system. This type of board comes with integrated DIP sockets on the front and wire-wrap pins on the back, making connections very convenient. That’s right, not a drop of solder was used on the board.

You can see 11 seconds of the pattern in the video after the break. We’re glad [Quinn] didn’t film the entire sequence, which would have taken some 22,410,541,156,499,040,202,730,815,585,272,939,064,275,544, 100,401,052,233,911,798,596 years (assuming a 5 Hz clock and using taps on bits 241 and 171 ).

Continue reading “You’ll Never See The End Of This Project” →