Friction Differential Drive Is A Laser-Cut Triumph

October 2, 2017 by 6 Comments

Here on Hackaday, too often do we turn our heads and gaze at the novelty of 3D printing functional devices. It’s easy to forget that other techniques for assembling functional prototypes exist. Here, [Reuben] nails the aspect of functional prototyping with the laser cutter with a real-world application: a roll-pitch friction differential drive built from just off-the shelf and laser-cut parts!

The centerpiece is held together with friction, where both the order of assembly and the slight wedged edge made from the laser cutter kerf keeps the components from falling apart. Pulleys transfer motion from the would-be motor mounts, where the belts are actually tensioned with a roller bearing mechanism that’s pushed into position. Finally, the friction drive itself is made from roller-blade wheels, where the torque transferred to the plate is driven by just how tightly the top screw is tightened onto the wheels. We’d say that [Reuben] is pushing boundaries with this build–but that’s not true. Rather, he’s using a series of repeatable motifs together to assemble a both beautiful and complex working mechanism.

This design is an old-school wonder from 2012 uncovered from a former Stanford course. The legendary CS235 aimed to teach “unmechanically-minded” roboticists how to build a host of mechanisms in the same spirit as MIT’s How-to-make-almost-Anything class. While CS235 doesn’t exist anymore, don’t fret. [Reuben] kindly posted his best lectures online for the world to enjoy.

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A Bit Of Mainstream Coverage For The Right To Repair

October 2, 2017 by 80 Comments

Here at Hackaday, we write for a community of readers who are inquisitive about the technology surrounding them. You wouldn’t be here if you had never taken a screwdriver to a piece of equipment to see what makes it work. We know that as well as delving inside and modifying devices being core to the hardware hacker mindset, so is repairing. If something we own breaks, we try to work out why it broke, and what we can do to fix it.

Unfortunately, we live in an age in which fixing the things we own is becoming ever harder. Manufacturers either want to sell us now hardware rather than see us repair what breaks, or wish to exercise total control over the maintenance of their products. They make them physically impossible to repair, for example by gluing together a cellphone, or they lock down easy-to-repair items with restrictive software, for example tractors upon which every replacement part must be logged on a central computer.

This has been a huge issue in our community for a long time now, but to the Man In The Street it barely matters. To the people who matter, those who could change or influence the situation, it’s not even on the radar. Which makes a piece in the British high-end weekly newspaper The Economist particularly interesting. Entitled “A ‘right to repair’ movement tools up“, it lays out the issues and introduces the Repair Association, a political lobby group that campaigns for “Right to repair” laws in the individual states of the USA.

You might now be asking why this is important, why are we telling you something you already know? The answer lies in the publication in which it appears. The Economist is aimed at politicians and influencers worldwide. In other words, when we here at Hackaday talk about the right to repair, we’re preaching to the choir. When they do it at the Economist, they’re preaching to the crowd who can make a difference. And that’s important.

You may recognise the tractors mentioned earlier as the iconic green-and-yellow John Deere. We’ve written about their DRM before.

Neon sign, All Electronics Service, Portland, Visitor7 [CC BY-SA 3.0].

Hackaday Prize Entry: Dynamometer For Post Stroke Rehabilitation

October 2, 2017 by 4 Comments

For those who have suffered a stroke, recovery is a long and slow process that requires rehabilitation to start as early as possible. Quite often, secondary stroke attacks complicate matters. Spasticity — muscle contraction and paresis — muscular weakness, are two of the many common after-effects of stroke. Recovery involves doing repeated exercises to strengthen the muscles and bring back muscle memory. Benchmarking progress becomes difficult when caregivers are only able to use qualitative means such as squeezing tennis balls to monitor improvement. To help provide quantitative measurements in such cases, [Sergei V. Bogdanov] is building a Dynamometer for Post-Stroke Rehabilitation. It is an Open Source, 4-channel differential force gauge for measuring and logging the progress of the patient. The device measures, graphs, and logs the force exerted by the four fingers when they push down on the four force gauges.

The device consists of four strain gauges obtained from cheap kitchen scales. The analog outputs from these are fed to HX-711 24-bit ADC boards. An Arduino Nano processes the data and displays it on two banks of eight-digit LED modules. [Sergei] also experimented with a 20×4 character LCD in place of the LED display. In the standalone mode, the device can only indicate the measured forces on the LED (or LCD) display which is calibrated to display either numerical values or a logarithmic scale. When connected to a serial port and using the (Windows only) program, it is possible to not only view the same information but also save it at regular, set intervals. The data can also be viewed in graphical form.

The project page provides links to their Arduino code, Windows monitor program as well as build instructions. Check out the related assistive technology project that [Sergei] is working on — A Post Stroke Spasticity Rehab Helper.

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Books You Should Read: Feynman’s Appendix To The Challenger Disaster Report

October 2, 2017 by 84 Comments

It isn’t really a book, but Richard Feynman’s Appendix to the Challenger Disaster Report is still definitely something you should read. It’s not particularly long, but it’s educational and relevant not just as an example of critical thinking in action, but as a reminder not to fool oneself; neither individually, nor on an organizational level. Sadly, while much was learned from the events leading to and surrounding the Challenger disaster, over thirty years later many of us can still find a lot of the same things to relate to in our own professional lives. There isn’t a single magic solution, because these problems are subtle and often masquerade as normal.

Feynman and the Challenger Disaster

Richard Feynman (1918-1988) was a Nobel Prize winning physicist and one of the best-known scientists of his time. In 1986 he somewhat reluctantly agreed to join the Rogers Commission, whose task was to investigate the Challenger disaster. The space shuttle Challenger had exploded a little more than a minute after launch, killing everyone on board. The commission’s job was to find out what had gone wrong and how it had happened, and figure out how to keep it from happening again.

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NIST Uses Optical Resonance To Probe Atoms

October 2, 2017 by 6 Comments

Have you ever stood under a dome and whispered, only to hear the echo of your voice come back much louder? Researchers at NIST used a similar principle to improve the atomic force microscope (AFM), allowing them to measure rapid changes in microscopic material more accurately than ever before.

An AFM works by using a minuscule sharp probe. The instrument detects deflections in the probe, often using a piezoelectric transducer or a laser sensor. By moving the probe against a surface and measuring the transducer’s output, the microscope can form a profile of the surface. The NIST team used a laser traveling through a circular waveguide tuned to a specific frequency. The waveguide is extremely close (150 nm) to a very tiny probe weighing about a trillionth of a gram. When the probe moves a very little bit, it causes the waveguide’s characteristics to change to a much larger degree and a photodetector monitoring the laser light passing through the resonator can pick this up.

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Get Hands-On At Supercon: Workshop Tickets Now Available

October 2, 2017 by 13 Comments

Build something cool and pick up new skills from the workshops at the Hackaday Superconference. Last week we announced all of the talks you’ll find at Supercon, and starting today you can reserve your spot at one of the workshops.

You must have a Superconference ticket in order to purchase a workshop ticket; buy one right now if you haven’t already. You can get mechanical with Haptics and Animatronics, take your product design from schematic to PCB and enclosure, brush up your embedded development on several choices of platform, make cell towers do your bidding, or dump way too many volts into a block of wood.

Space in these workshops is limited so make sure to sign up before all the seats are taken. The base price for workshops is $10 (basically a “skin in the game” price to encourage those who register to show up). Any tickets priced above that base is meant to cover the material expense of the workshop. Here’s what we have planned:

Embedded Programming with Black Magic and the Lights On

Piotr Esden-Tempski

Sunday Afternoon

Embedded systems programming has earned a bad reputation of being difficult to master. Especially in the open-source world, most people associate it with cut and pasted code that is difficult to debug. The usual tools we have to debug embedded systems are a blinking LED and, if we are lucky, printf statements through a serial port. In this self guided workshop we will show you how easy it can be to have full insight into your microcontroller using fully open source tools that are on par with expensive proprietary closed-source solutions.

Fun with High Voltage

Will Caruana

Sunday Morning

This workshop is about making Lichtenberg figures. A Lichtenberg figure is a piece of art though the multiplication of a few thousands of volts to burn wood. We will cover the science behind this art form as well as the safety and lastly we will be getting hands on experience in being able to using high voltage transformers to make these burnings into wood and make coasters you can take home.

Designing Electronic Textures

Noah Feehan

Sunday Afternoon

Participants will learn the physics behind electrovibration, and then get to play/design for it using a new open-source board called WEFT. After the workshop, you’ll know how to deploy electrovibration in your projects, and understand the feeling of different waveforms.

End to End Product Design with Eagle and Fusion 360

Matt Berggren

Saturday Morning

In this session, we’ll take you end to end, from building a new schematic, simulating a circuit using EAGLE’s built-in SPICE simulator, laying out a PCB, generating mfg files and include some tips & tricks for milling boards and making stencils. We’ll also take you thru the link between electronics and mechanics using Fusion360. Alongside EAGLE we’ll build an enclosure and generate the mfg outputs for your mechanical design (CAM, 3D prints, etc). We’ll look at library management across electronics and mechanics and bidirectional synchronization between both of these domains. This is more than an intro, as Matt’s always good for some essential, oft-missed background and tips with EAGLE you might never have known otherwise.

AVR® MCU Effortless Design Workshop: Prototyping with Sensors and BLE

Bob Martin, Senior Staff Engineer

Sunday Morning

This hands-on training session will walk you through how to develop an embedded sensor node prototype with Bluetooth® Low Energy (BLE) connectivity. You will speed through configuration of the AVR microcontroller, sensor interface and communications interface setup by using Atmel Start, a graphical programming interface. This tool will generate libraries with simple APIs so you can spend time working on your solution instead of messing with registers or communication protocols.

Rapid Prototyping and Linux Kernel Development with the PocketBeagle® Platform

Robert Nelson

Saturday Afternoon

The newly introduced PocketBeagle® is an ultra-tiny-yet-complete Linux-enabled, community-supported, open-source USB-key-fob computer. By leveraging the Octavo SIP, the PocketBeagle offers complete BeagleBoard functionality and includes 512MB DDR3 RAM, 1-GHz ARM Cortex-A8 CPU, 2x 200-MHz PRUs, ARM Cortex-M3, 3D accelerator, power/battery management and EEPROM. The board offers lots of GPIOs, on board peripherals and various expansion capabilities via multiple headers and the Mikroelektronika click board interface. During this course you will learn about pin configuration, how to create a Linux distribution, reconfiguring io on the fly and how to leverage expansion modules. Attendees will leave with their very own PocketBeagle and a couple other surprises as well.

Cellular Connectivity for Your Next Hardware Project

Ben Strahan and Chris Gammell

Saturday Afternoon

Your project shouldn’t be constrained by the range of a WiFi signal. This workshop will show you how to connect to cellular towers via a serial link, get connected into the cloud and reliably start transmitting data. This workshop is suitable for people just getting started in the firmware ecosystem up through advanced firmware engineers. Advanced members of the workshop will have the opportunity to hack their conference badge to connect to cell towers. Sign up for this workshop to add another connection method to your hardware development toolbox.

An Introduction to Animatronics with Laser Cut Tentacle Mechanisms

Joshua Vasquez

Saturday Morning

Animatronics are way cool, but the hacker community rarely ventures farther than a few hobby servos and “dem-blinkin’ LEDs.” In this workshop, I’ll get you cozy with tentacle mechanisms that you can build with just a laser cutter and a few hand tools. There are three big takeaways from this workshop. We’ll build up a two-stage controller reusable in other projects, muscle up our vocabulary of off-the-shelf parts for cable mechanisms, and discover a few laser-cut design techniques.

Superconference workshops tend to sell out extremely quickly. Don’t wait to get your ticket.

Manufacturing Your Own Single-Origin Tea

October 2, 2017 by 33 Comments

It’s nice to take a break from hacking together the newest bleeding-edge technology, relax, and enjoy a beverage. It’s no surprise that hacks devoted to beer and coffee roasting are popular. We’ve also seen a few projects helping brew the perfect cup of tea, but none involving the actual production of tea. Today we’re going to take a short recess from modernity and explore this ancient tradition.

Consumption of tea is about equal to all other manufactured beverages, such as coffee and alcohol, combined. It is hands-down the most popular manufactured beverage in the world, and we thought it would be interesting to make some ourselves. Also the local tea is so bitter that it’s used to clean things, and it works alarmingly well. To each their own!

I started by driving into Vietnam’s Central Highlands, down what Google simply refers to as ‘unnamed road’, to about 11°52’59.3″N 108°33’49.5″E. I asked around until I found a street vendor that knew a farmer at the nearby tea plantation, and would sell us five kilograms of fresh tea. I carried it 330 kilometers back to the city, because I’m a sane person that does normal things.

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