Ask Hackaday: How Hard Is It To Make A Bad Solder Joint?

July 8, 2016 by Jenny List 70 Comments

When you learn to solder, you are warned about the pitfalls of creating a solder joint. Too much solder, too little solder, cold joints, dry joints, failing to “wet” the joint properly, a plethora of terms are explained if you read one of the many online guides to soldering.

Unsurprisingly it can all seem rather daunting to a novice, especially if they are not used to the dexterity required to manipulate a tool on a very small-scale at a distance. And since the soldering iron likely to be in the hands of a beginner will not be one of the more accomplished models with fine temperature control and a good tip, it’s likely that they will experience most of those pitfalls early on in their soldering career.

As your soldering skills increase, you get the knack of making a good joint. Applying just the right amount of heat and supplying just enough solder becomes second nature, and though you still mess up from time to time you learn to spot your errors and how to rework and fix them. Your progression through the art becomes a series of plateaux, as you achieve each new task whose tiny size or complexity you previously thought rendered it impossible. Did you too recoil in horror before your first 0.1″ DIP IC, only to find it had been surprisingly easy once you’d completed it?

A few weeks ago we posted a Hackaday Fail of the Week, revolving around a soldering iron failure and confirmation bias leading to a lengthy reworking session when the real culprit was a missing set of jumpers. Mildly embarrassing and something over which a veil is best drawn, but its comments raised some interesting questions about bad solder joints. In the FoTW case I was worried I’d overheated the joints causing them to go bad, evaporating the flux and oxidising the solder. This was disputed by some commenters, but left me with some curiosity over bad solder joints. We all know roughly how solder joints go wrong, but how much of what we know is heresay? Perhaps it is time for a thorough investigation of what makes a good solder joint, and the best way to understand that would surely be to look at what makes a bad one.

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Tearing Into Delta Sigma ADC’s

July 7, 2016 by Bil Herd 33 Comments

It’s not surprising that Analog to Digital Converters (ADC’s) now employ several techniques to accomplish higher speeds and resolutions than their simpler counterparts. Enter the Delta-Sigma (Δ∑) ADC which combines a couple of techniques including oversampling, noise shaping and digital filtering. That’s not to say that you need several chips to accomplish this, these days single chip Delta-Sigma ADCs and very small and available for a few dollars. Sometimes they are called Sigma-Delta (∑Δ) just to confuse things, a measure I applaud as there aren’t enough sources of confusion in the engineering world already.

I’m making this a two-parter. I will be talking about some theory and show the builds that demonstrate Delta-Sigma properties and when you might want to use them.

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Build A 3D Printer Workhorse, Not An Amazing Disappointment Machine

July 6, 2016 by Moritz Walter 68 Comments

3D printers have become incredibly cheap, you can get a fully workable unit for $200 – even without throwing your money down a crowdfunded abyss. Looking at the folks who still buy kits or even build their own 3D printer from scratch, investing far more than those $200 and so many hours of work into a machine you can buy for cheap, the question “Why the heck would you do that?” may justifiably arise.

The answer is simple: DIY 3D printers done right are rugged workhorses. They work every single time, they never break, and even if: they are an inexhaustible source of spare parts for themselves. They have exactly the quality and functionality you build them to have. No clutter and nothing’s missing. However, the term DIY 3D printer, in its current commonly accepted use, actually means: the first and the last 3D printer someone ever built, which often ends in the amazing disappointment machine.

This post is dedicated to unlocking the full potential in all of these builds, and to turning almost any combination of threaded rods and plywood into a workshop-grade piece of equipment.

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The Future Of Eagle CAD

July 5, 2016 by Brian Benchoff 113 Comments

Last week, Autodesk announced their purchase of CadSoft Eagle, one of the most popular software packages for electronic design automation and PCB layout.

Eagle has been around for nearly thirty years, and has evolved to become the standard PCB design package for electronic hobbyists, students, and engineering firms lead by someone who learned PCB design with Eagle. The reason for this is simple: it’s good enough for most simple designs, and there is a free version of Eagle. The only comparable Open Source alternative is KiCad, which doesn’t have nearly as many dedicated followers as Eagle. Eagle, for better or worse, is a standard, and Open Source companies from Sparkfun to Adafruit use it religiously and have created high-quality libraries of parts and multiple tutorials

I had the chance to talk with [Matt Berggren], former Hackaday overlord who is currently serving as the Director of Autodesk Circuits. He is the person ultimately responsible for all of Autodesk’s electronic design products, from Tinkercad, 123D, Ecad.io, and project Wire, the engine behind Voxel8, Autodesk’s 3D printer that also prints electronics. [Matt] is now the master of Eagle, and ultimately will decide what will change, what stays the same, and the development path for Eagle.

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Retrotechtacular: How Solidarity Hacked Polish TV

July 5, 2016 by Jenny List 52 Comments

In the 1980s, Poland was under the grip of martial law as the Communist government of General Wojciech Jaruzelski attempted to repress the independent Solidarity trade union. In Western Europe our TV screens featured as much coverage of the events as could be gleaned through the Iron Curtain, but Polish state TV remained oblivious and restricted itself to wholesome Communist fare.

In September 1985, TV viewers in the city of Toruń sat down to watch an action adventure film and were treated to an unexpected bonus: the screen had a brief overlay with the messages “Solidarity Toruń: Boycotting the election is our duty,” and “Solidarity Toruń: Enough price hikes, lies, repression”. Sadly for the perpetrators, they were caught by the authorities after their second transmission a few days later when they repeated the performance over the evening news bulletin, and they were jailed for four months.

The transmission had been made by a group of dissident radio astronomers and scientists who had successfully developed a video transmitter that could synchronise itself with the official broadcast to produce an overlay that would be visible on every set within its limited transmission radius. This was a significant achievement using 1980s technology in a state in which electronic components were hard to come by. Our description comes via [Maciej Cegłowski], who was able to track down one of the people involved in building the transmitter and received an in-depth description of it.

Transmission equipment seized by the Polish police.

The synchronisation came courtesy of the international effort at the time on Very Long Baseline Interferometry, in which multiple radio telescopes across the world are combined to achieve the effect of a single much larger instrument. Before GPS made available a constant timing signal the different groups participating in the experiment had used the sync pulses of TV transmitters to stay in time, establishing a network that spanned the political divide of the Iron Curtain. This expertise allowed them to create their transmitter capable of overlaying the official broadcasts. The police file on the event shows some of their equipment, including a Sinclair ZX Spectrum home computer from the West that was presumably used to generate the graphics.

There is no surviving recording of the overlay transmission, however a reconstruction has been put on YouTube that you can see below the break, complete with very period Communist TV footage.

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Retrotechtacular: DC To DC Conversion By Vibrator

July 4, 2016 by Al Williams 42 Comments

Electricity comes in two basic forms: Alternating Current (AC) and Direct Current (DC). DC is handy to use and is easy to analyze. However, AC has some useful properties too. In particular, AC current can operate a transformer which can step it up or down easily. Power is conserved, of course (well, actually, you get less power because of losses in the transformer).

You can’t do that trick with pure DC. You can reduce a voltage, although that typically wastes power in heat (for example, a voltage divider or linear regulator). You can’t readily increase a DC voltage unless you convert it into some sort of AC first.

This was a particularly bad problem in the era of tubes–especially tubes in car radios. The car’s voltage was probably 12V but the tube’s plates might take hundreds of volts. What do you do? Some old car radios used what is called a dynamotor. This is just a motor and a generator in one box. You could spin the motor with 12V and have the generator produce a different voltage (even a DC voltage).

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Hackaday Links: July 3, 2016

July 3, 2016 by Brian Benchoff 10 Comments

This week, Popular Mechanics published cutaway diagrams of ships that will be seen in Star Trek: Beyond, released later this month. This is your cue for spoilers for the remainder of this paragraph. The USS Franklin looks suspiciously like – and was likely built after – the NX-01, the titular ship of Star Trek: Enterprise. The Abrams-verse Franklin was the first Warp 4 ship, yet the prime universe NX-01 was the first Warp 5 ship, with previous ships having trouble reaching Warp 2. We must now consider the Abrams-verse Trek is not a parallel universe to prime-universe Trek and should therefore be considered a completely separate canon (yes, even the destruction of Vulcan. If you see the new Star Trek movie, the NX-01 launched in 2151, and your suggested viewing beforehand is ST:ENT, S02E24, First Flight.

The Mechaduino is a Hackaday Prize entry that turns steppers into closed-loop servos. It’s a phenomenal idea, and now it’s a Kickstarter.

Walk into a dollar store, and you’ll find stupid solar powered electronic flower pots. They’re bits of plastic that shake a plastic flower back and forth when placed in the sun. They’re selling millions, and I have no idea why. [Scott] put a jolly wrencher on one of these flower pots. Really, this is just an exercise in 3D printing, but [Scott] printed the jolly wrencher. We don’t see a lot of that, due to how difficult it is to render the wrencher in OpenSCAD.

In just a few hours, Juno will perform an insertion burn around Jupiter. Does this mean pretty pictures? Not quite yet. This is the closest a spacecraft has ever gotten to Jupiter, and over thirty or forty orbits, Juno will fly between Jupiter’s massive radiation belts. Here’s the NASA trailer.

This video recently caught the Internet’s attention. It’s squares and circles that when put next to a mirror look like circles and squares. Yes, it’s weird. People have 3D printers, so of course these ambiguous objects were quickly reverse engineered and printed. Here’s how they work

It looks like Brexit has caught up to Mouser. Here’s their country select dialog for eu.mouser.com. Thanks [Tom] for the screencap.