The Fascinating World Of Solder Alloys And Metallurgy

May 30, 2019 by Maya Posch 57 Comments

Solder is the conductive metal glue that one uses to stick components together. If you get the component and the PCB hot enough, and melt a little solder in the joint, it will stay put and conduct reliably. But it’s far from simple.

There are many different solder alloys, and even the tip of the soldering iron itself is a multi-material masterpiece. In this article, we’ll take a look at the metallurgy behind soldering, and you’ll see why soldering tip maintenance, and regular replacement, is a good idea. Naturally, we’ll also touch upon the role that lead plays in solder alloys, and what the effect is of replacing it with other metals when going lead-free. What are you soldering with? Continue reading “The Fascinating World Of Solder Alloys And Metallurgy” →

Atomic Power Gets Small

May 29, 2019 by Al Williams 175 Comments

There was a time when nuclear power plants were going to save the world. Barring accidents, the plants are clean and generate a lot of power. However, a few high-profile accidents and increased public awareness of some key issues have made nuclear power a hard sell, at least in the United States. The fastest growing nuclear power-related business in the US — according to sources — is companies decommissioning nuclear power plants. However, there’s a move afoot to make nuclear power a viable solution again. The company behind it says their plants will be cheaper to build, cheaper to operate, and are much safer than conventional plants. Are those claims reasonable?

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Loads Of Testing Yields New, Reliable, And Cheap Leather Hardening Technique

May 26, 2019 by Donald Papp 36 Comments

Leather hardening has been around for such a long time that one might think that there was little left to discover, but [Jason F. Timmermans] certainly showed that is not the case. Right around the end of 2018 he set up experiments to compare different techniques for hardening leather, and empirically determine the best options. After considerable effort, he crafted a new method with outstanding results. It’s part of his exhaustive testing of different techniques for hardening leather, including some novel ones. It was a considerable amount of work but [Jason] says that he gathered plenty of really useful information, which we’re delighted that he took the time to share it.

According to [Jason], the various methods of hardening can be separated into four groups:

Thermal: heat-treating at 180 ºF or higher, usually via some kind of boiling or baking process.
Chemical: soaking in a substance that causes changes in the leather. Some examples include ammonia, vinegar, acetone, brine, and alcohol.
Mechanical: hammering the leather.
“Stabilizing” methods: saturating the leather with a substance to add rigidity and strength without otherwise denaturing the leather itself. Examples include beeswax, pine pitch, stearic acid, and epoxy.

We recommend making the time to follow the link in the first paragraph and read the full results, but to summarize: heat-treating generally yields a strong but brittle product, and testing revealed stearic acid — which resembles a kind of hard, dense wax at room temperature — was an early standout for overall great results. Stearic acid has many modern uses and while it was unclear from [Jason]’s reasearch exactly when in history it became commonplace, at least one source mentioned it as a candidate for hardening leather.

But the story doesn’t stop there. Unsatisfied with simply comparing existing methods, [Jason] put a lot of work into seeing if he could improve things. One idea he had was to combine thermal treatment with a stabilizer, and it had outstanding results. The winning combination (named X1 in his writeup) was to preheat the leather then immerse it in melted stearic acid, followed by bringing the temperature of the combination to 200 ºF for about a minute to heat treat the leather at the same time. [Jason]’s observation was that this method “[B]lew the rest out of the water. Cutting the sample to view the cross section was like carving wood. The leather is very rigid and strong.”

The world may not revolve around leather the way it used to, but there’s still stuff to learn and new things to discover. For example, modern tools can allow for novel takes on old techniques, like using 3D printing to create custom leather embossing jigs.

Piezoelectric Crystals Explained

May 24, 2019 by Al Williams 25 Comments

Summer in the Northern hemisphere means outdoor cooking. Matches are old school, and you are more likely to use a piezoelectric lighter to start your grill. [Steve Mould] has one, but he didn’t understand the physics behind why it works, so he decided to do the research and share it in a video.

The first two minutes is a recap of things you already know. But after that [Steve] gets into the crystal lattice structure of quartz. Using some computer animations and some peanut butter lids he shows you exactly why compressing the crystal generates electricity.

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Easy DIY Gecko Tape

May 23, 2019 by Zoe Skyforest 7 Comments

Geckos are amazing creatures, with the ability to walk on and stick to all manner of surfaces. If you’ve ever woken up to see lizards on your ceiling, you’re already familiar with their capabilities. The mechanisms behind this have been an area of much research in recent times, and [The Thought Emporium] decided to try and recreate the effect himself (Youtube video, embedded below).

The way geckos stick to surfaces is through the use of nano-scale hairs on their feet. These hairs dramatically increase the surface area of contact between the gecko and the surface in question. This allows the usually-small intermolecular forces to stack up and keep the gecko adhered.

Several teams have managed to create synthetic substances that recreate this ability; indeed we’ve featured some here before. In this case, experimentation started with an attempt to generate the requisite nanostructures by casting RTV silicone on a microporous filter. This was unsuccessful, with the hairs on the surface of the material created being too sparse and at random angles. The next stage involved attempting to use a tattoo gun, needles, and finally sharpened tungsten wires to pattern wax, which could then have silicone cast onto it to pick up the geometry. This too was unsuccessful, as it wasn’t possible to generate tiny enough features to generate the effect.

The final experiment involved casting silicone upon a 1000 line per millimeter diffraction grating. This generated tiny ridges on the surface of the silicone, and greatly improved its sticking ability. While the ridges generated aren’t as capable as gecko feet or professionally-produced films, they do have an impressive weight holding ability. A small section of the silicone was able to hold over 20 pounds for an extended period in testing.

It’s a great example of how to do seemingly complicated science with materials that can be easily acquired for the home workshop. We’d love to see just how strong a gecko tape could be produced with more work done on this method. Video after the break.

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By The Numbers: Which Rapper’s Rhymes Are The Freshest?

May 21, 2019 by Drew Littrell 18 Comments

Beats and rhymes are life in the world of hip-hop. A rapper’s ability to seamlessly merge the two is the mark of a master wordsmith. Ranking a rapper’s contributions to hip-hop will forever remain subjective, however [Matt] sought to apply a more quantitative approach to the matter. He created an interactive data set containing all the lyrics from over 150 rappers in order to determine which rapper’s vocabulary was the largest. Now everyone can know definitively which rapper’s rhymes truly are “the freshest”.

The study encompasses hip-hop artists from the last thirty years, pitting recent hit-makers like Lil Uzi Vert against veteran artists like KRS-One. To ensure everything is on even playing field [Matt] limited the study to the first 35,000 lyrics of each artist including any material on a mixtape, EP, or full album release. Rappers’ vocabulary was then plotted according to the total number of unique words found in their lyrics (i.e.: “shorty” and the alternative spelling “shawty” were each considered to be unique words). Oddly enough, there were some notable exclusions from the list as artists like Chance the Rapper, Queen Latifah, and The Notorious B.I.G’s discography did not exceed the 35,000 lyrics mark.

When digging into the data, there was a downward trend in the vocabulary used amongst popular artists of the last decade. [Matt] attributed this trend to the fact that many of these artists have modeled their music to reflect the pop/rock music structure that makes use of simple, repetitive choruses. While others may attribute this downward trend to a general lack of talent when it comes to lyricism, however, it should be noted that the economics of music streaming platforms have had an effect on the average song length. Though whatever era of hip-hop you subscribe to, it is always interesting to see where your favorite emcees rank.

Transparent And Flexible Circuits

May 17, 2019 by Al Williams 4 Comments

German researchers have a line on 3D printed circuitry, but with a twist. Using silver nanowires and a polymer, they’ve created flexible and transparent circuits. Nanowires in this context are only 20 nanometers long and only a few nanometers thick. The research hopes to print things like LEDs and solar cells.

Of course, nothing is perfect. The material has a sheet resistance as low as 13Ω/sq and the optical transmission was as high as 90%. That sounds good until you remember the sheet resistance of copper foil on a PCB is about 0.0005Ω.

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