Resurrection — Pressing WW2 Radio Equipment Back Into Service

November 9, 2016 by Gregory L. Charvat 37 Comments

Mass production was key to survival during the Second World War. So much stuff was made that there continues to be volumes of new unpacked stuff left over and tons of used equipment for sale at reasonable prices. Availability of this war surplus provided experimenters in the mid 20th century with access to high performance test equipment, radio equipment, and high quality components for the first time.

Even today this old stuff continues to motivate and inspire the young generations because of its high build quality, unique electro-mechanical approaches, and overall innovative designs which continue to be relevant into the 21st century. In this post we will show you how to get started in the hobby of resurrecting WW2 radio equipment and putting it back on the air.

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Crossing Wheatstone Bridges

November 8, 2016 by Steven Dufresne 18 Comments

The Wheatstone bridge is a way of measuring resistance with great accuracy and despite having been invented over 150 years ago, it still finds plenty of use today. Even searching for it on Hackaday brings up its use in a number of hacks. It’s a fundamental experimental device, and you should know about it.

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Tiny Game Boy (That Plays Witcher 3) And Other Things That Blew My Mind

November 7, 2016 by Mike Szczys 48 Comments

For years Sprite_TM has been my favorite hacker, and yet he continues to have an uncanny ability to blow my mind with the hacks that he pulls off even though I’m ready for it. This weekend at the Hackaday SuperConference he threw down an amazing talk on his tiny, scratch-built, full-operational Game Boy. He stole the badge hacking show with a Rick Roll, disassembled the crypto challenge in one hour by cutting right to the final answer, and managed to be everywhere at once. You’re a wizard ~~Harry~~ Sprite!

Here’s what’s crazy: these are the antics of just one person of hundreds who I found equally amazing at the conference. It feels impossible to convey to you the absolute sincerity I have when I say that SuperCon was far and away the best conference I’ve ever been to or have even heard about. It managed to outpace any hyperbole I constructed leading up to the weekend. This morning felt like I was waking up from a dream and desperately wanted to fall asleep again.

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A Realistic Look At The Death Of A Standard

November 7, 2016 by Gerrit Coetzee 239 Comments

A bit ago I wrote an article called, “Death To The 3.5mm Audio Jack, Long Live Wireless.” A few readers were with me, a few were indifferent, many were vehemently against me, and there was a, not insubstantial, subset in a pure panic about the potential retirement of a beloved connector. Now I used a lot of opinionated language dispersed with subjectively evaluated facts to make a case that the connector is out. Not today maybe, but there is certainly a tomorrow not so far off where there are more wireless headsets at the electronics store than wired ones.

I think I saw a laserdisc player in operation exactly once. — I think I saw a Laserdisc player in operation exactly once.

So what happens when a standard dies? What happens when technology starts to move on? Let’s take a look at the CD-ROM. Continue reading “A Realistic Look At The Death Of A Standard” →

Dtto Explorer Modular Robot Wins 2016 Hackaday Prize

November 5, 2016 by Mike Szczys 29 Comments

Dtto, a modular robot designed with search and rescue in mind, has just been named the winner of the 2016 Hackaday Prize. In addition to the prestige of the award, Dtto will receive the grand prize of $150,000 and a residency at the Supplyframe Design Lab in Pasadena, CA.

This year’s Hackaday Prize saw over 1,000 entires during five challenge rounds which asked people to Build Something that Matters. Let’s take a look at the projects that won the top five prizes. They exemplify the five challenge themes: Assistive Technologies, Automation, Citizen Scientist, Anything Goes, and Design Your Concept.

Dtto — Explorer Modular Robot

Grand Prize Winner ($150,000 and a residency at the Supplyframe Design Lab): Dtto is modular robot built with 3D printed parts, servo motors, magnets, and readily available electronics. Each module consists of two boxes, rounded on one side, connected by a bar. The modules can join with each other in many different orientations using the attraction of the magnets. Sections can separate themselves using servo motors.

Dtto is groundbreaking in its ability to make modular robots experimentation available to roboticists and hobbiests everywhere by sidestepping what has traditionally been a high-cost undertaking. While it’s easy to dismiss this concept, the multitude of different mechanisms built from modules during testing drives home the power of the system.

imaging-dome-400x300

Affordable Reflectance Transformation Imaging Dome

Second Place ($25,000): Reflectance Transformation Imaging is a method of photographing artifacts multiple times with a fixed camera location but changing lighting locations. When these images are combined into an interface after the fact, it allows for different textures, surface features, and material properties to be observed. Currently there are no commercial version of hardware available for this technique.

Laser Cut Optics Bench

Third Place ($10,000): An optics bench is a series of jigs used to hold and precisely align elements for optical experiments. Traditionally this meant highly specialized equipment starting in the tens-of-thousands of dollars. But schools, hackerspaces, and individuals don’t need top-of-the-line equipment to begin learning about optics. The project has designed holders for salvaged optics and the ancillary materials to conduct experiments, and even includes a standardized carrying case design.

A New High Accuracy Tilt Sensor

Fourth Place ($10,000): This is a reimaging of a Linear Variable Differential Transformer (LVDT). Traditionally, tilt sensors based on LVDTs are built like a small tube with an iron core that can slide from one end to the other as the tube is tilted. This new sensor turns the tube into a hollow ring, and replaces the iron core with ferrofluid (a liquid with the properties of metal). What results is a brand new sensor with properties unavailable in previous tilt sensors.

Mechaduino

Fifth Place ($5,000). Stepper motors are known for accurate movement, but they are often used as open loop systems and prone to lose track of position either from missed steps or outside interference. Mechaduino adds a high accuracy magnetic encoder to any of several commonly available stepper motors, closing that loop and adding functionality. This includes positional awareness, but goes for beyond to velocity and torque control, and user interaction.

Having finished the Tools of the Trade series on circuit board assembly, let’s look at some of the common methods for doing enclosures. First, and possibly the most common, is injection molding. This is the process of taking hot plastic, squirting it through a small hole and into a cavity, letting it cool, and then removing the hardened plastic formed in the shape of the cavity.

The machine itself has three major parts; the hopper, the screw, and the mold. The hopper is where the plastic pellets are dumped in. These pellets are tiny flecks of plastic, and if the product is to be colored there will be colorant pellets added at some ratio. The hopper will also usually have a dehumidifier attached to it to remove as much water from the pellets as possible. Water screws up the process because it vaporizes and creates little air bubbles.

Next the plastic flecks go into one end of the screw. The screw’s job is to turn slowly, forcing the plastic into ever smaller channels as it goes through a heating element, mixing the melted plastic with the colorant and getting consistent coloring, temperature, and ever increasing pressure. By the time the plastic is coming out the other end of the screw, and with the assistance of a hydraulic jack, it can be at hundreds of tons of pressure.

Finally, the plastic enters the mold, where it flows through channels into the empty cavity, and allowed to sit briefly to cool. The mold then separates and ejector pins push the part out of the cavity.

Continue reading “Tools Of The Trade — Injection Molding” →