Hackaday Prize Entry: A Cheaper Soldering Solution

May 7, 2016 by Brian Benchoff 32 Comments

Everyone goes through a few phases during their exploration of electrons, and nowhere is this more apparent than the choice of soldering iron. The My First Soldering Iron™ is an iron that plugs directly into the wall, and doesn’t have temperature control. They’re cheap, and electronics isn’t for everyone, giving the quitters the opportunity to take up woodburning as a hobby. The next step up is a temperature controlled iron, probably an Aoyue or Hakko. The best soldering iron? You’re looking at a Metcal or Weller, and your wallet will become a few hundred dollars lighter.

Your My First Soldering Iron™ need not be terrible, though. For his project for The Hackaday Prize, [HP] is working on a soldering iron that is cheap, accurate, and uses the very nice Weller RT tips. No, it’s not as good as a Metcal or proper Weller, but it’s good enough for some fine soldering work and will give the Aoyues and Hakkos a run for their money.

If price is a reasonable measure of the quality of a soldering iron, the irons that use these Weller RT tips are the best irons around. The tips, though, are pretty cheap: about $30, which gets you a heater and thermistor and not much else. There have been numerous reverse engineering efforts for this iron ([1] and [2]), and even a few Arduino-based circuits that replicate the functionality of the Weller base unit.

[HP] is going in a different direction to heat these iron tips. Instead of building a big box to hold the electronics, he’s building everything into the handle of the soldering iron. With brains donated from an ATMega168, a few op-amps, MOSFETS, and a single power jack, [HP] can heat up this soldering iron tip in a compact, hand-held unit.

For his Hackaday Prize entry, [HP] did a rundown of soldering pen in a video. You can check that out below.

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Designing Flat Flexible PCBs

May 5, 2016 by Brian Benchoff 19 Comments

You can find flex PCBs in just about every single piece of consumer electronics. These traces of copper laminated in sheets of Kapton are everywhere, and designing these cables, let alone manufacturing them, is a dark art for the garage electronics wizard. Having these flat flex cables and PCBs manufactured still requires some Google-fu or a contact at a fab house, but at least now designing these cables is a solved problem.

[Oli] needed a way to connect two PCBs together over a moving part. Usually this means some sort of connector or cable, but he’s developed an even better solution – flexible PCB connections. To generate these copper traces sandwiched between a few layers of Kapton, [Oli] wrote a Python script to take a set of parameters, and produces an design for Eagle that includes all the relevant bits.

Of course, with a flexible PCB layout, the question of how to get these manufactured comes up. we’ve seen a few creative people make flexible PCBs with a 3D printer and there’s been more than one Hackaday Prize project using these flex PCBs. [Oli] says any manufacturer of flexible circuits should be able to reproduce everything generated from his script without much thinking at all. All we need now is for OSH Park to invent purple Kapton.

You can grab [Oli]’s script on his GitHub.

Engineering Meets Craftsmanship In This Guitar Fretting Jig

April 27, 2016 by Dan Maloney 6 Comments

Cutting the slots in a guitar’s neck for the frets requires special tooling, and [Gord]’s contribution to his friend’s recent dive into lutherie was this lovingly engineered and crafted fret mitering jig. We’d love to have a friend like [Gord].

We’ve covered a number of [Gord]’s builds before, and craftsmanship is the first thing that comes to mind whether the project is a man-cave clock or artisanal soaps. For this build, he stepped up the quality a notch – after all, if you’re going to build something you could buy for less than $200, you might as well make it a thing to behold.

There’s plenty to feast the eyes on here – an oak bed with custom logo, the aluminum jig body with brass accents, and the precision bearings that guide the pricey backsaw. Functionality abounds too – everything is adjustable, from the depth of cut to the width of the saw blade. There’s even a place to store the adjustment tool.

The result? Well, let’s just say that [Gord] and his friend [Fabrizio] are kindred spirits in the craftsmanship department. And [Fab]’s not a bad axeman either, as the video below shows.

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DIY Vacuum Chamber Proves Thermodynamics Professor Isn’t Making It All Up

April 26, 2016 by Gerrit Coetzee 34 Comments

[Mr_GreenCoat] is studying engineering. His thermodynamics teacher agreed with the stance that engineering is best learned through experimentation, and tasked [Mr_GreenCoat]’s group with the construction of a vacuum chamber to prove that the boiling point of a liquid goes down with the pressure it is exposed to.

His group used black PVC pipe to construct their chamber. They used an air compressor to generate the vacuum. The lid is a sheet of lexan with a silicone disk. We’ve covered these sorts of designs before. Since a vacuum chamber is at max going to suffer 14.9 ish psi distributed load on the outside there’s no real worry of their design going too horribly wrong.

The interesting part of the build is the hardware and software built to boil the water and log the temperatures and pressures. Science isn’t done until something is written down after all. They have a power resistor and a temperature probe inside of the chamber. The temperature over time is logged using an Arduino and a bit of processing code.

In the end their experiment matched what they had been learning in class. The current laws of thermodynamics are still in effect — all is right in the universe — and these poor students can probably save some money and get along with an old edition of the textbook. Video after the break.

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USB Soldering Iron Is Surprisingly Capable

April 25, 2016 by Dan Maloney 49 Comments

We know what you’re thinking. There’s no way an 8 watt USB-powered soldering iron could be worth the $5 it commands on eBay. That’s what [BigClive] thought too, so he bought one, put the iron through a test and teardown, and changed his mind. Can he convince you too?

Right up front, [BigClive] finds that the iron is probably not suitable for some jobs. Aside its obvious unsuitability for connections that take a lot of heat, there’s the problem of leakage current when used with a wall-wart USB power supply. The business end of the iron ends up getting enough AC leak through the capacitors of the power supply to potentially damage MOSFETs and the like. Then again, if you’re handy to an AC outlet, wouldn’t you just use a Hakko? Seems like the iron is best powered by a USB battery pack, and [BigClive] was able to solder some surprisingly beefy connections that way. The teardown and analysis reveal a circuit that looks like it came right out of a [Forrest M. Mims III] book. We won’t spoil the surprise for you – just watch the video below.

While not truly cordless like this USB-rechargeable iron, we’d say that for the price, this is a pretty capable iron for certain use cases. Has anyone else tried one of these? Chime in on the comments and let us know what you think.

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DIY Spot Welder Doesn’t Look Like It Will Immediately Kill You

April 24, 2016 by Gerrit Coetzee 30 Comments

We love hacks that involve mains voltage, but most of the time, for safety’s sake, we secretly hope for that one macabre commenter that details every imaginable way the questionable design choices will result in death. This spot welder may still be dangerous, but it looks like they took some precautions to make it non-lethal, and that counts for a lot.

After their extremely questionable high speed belt sander, this one is, refreshingly, extremely well done. It starts of as a dead standard microwave spot welder build: take apart microwave, try not to die from large capacitor, remove coil, modify coil, and hook up.

After that, it gets to some nice heavy metal music fabrication. Aside from a slightly shocking number of fresh OSHA reportable hand injuries (wear gloves!) the build goes together well. A lot of planning obviously went into it, from the actively cooled transformer to what appears to be a resettable timer circuit for the weld duration, not to mention the way that it just fit together so well at the end. There were some neat ideas as far as home mechanics go that we’ll be using in some of our projects.

In the end, the proof is in the spot-weld. The timer is set, pedal gets pressed down, and when tested, the sheet metal breaks instead of the weld. Video after the break.

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Magical Blinky Capacitive Sensing Tweezers

April 23, 2016 by Brian Benchoff 10 Comments

Electronic tweezers – the kind that can test the voltage between two contacts, the resistance of an SMD resistor, or the capacitance of a circuit – are very cool and very useful if somewhat expensive. We’ve seen commercial versions of these smart tweezers, hacks to make them more useful, and homebrew versions that still work very well. All of these versions are pretty large, as far as tweezers go. [kodera2t]’s version of electronic tweezers submitted for this year’s Hackaday Prize goes in the other direction: it’s the smallest set of electronic tweezers that’s still useful.

[kodera]’s electronic sensing tweezers only measure capacitors, and for good reason: chip caps usually don’t have values printed on them. These tweezers don’t print out the value of a cap on a display, either. Instead, these tweezers just flash an LED if the value of the cap is above 0.1uF. It’s simple, but surprisingly useful for most soldering jobs.

The circuit for this pair of magical tweezers is about as simple as if can get, with all the smarts contained in a very small ATtiny10. The PCB [kodera] designed is smaller than the coin cell battery, and with the help of some copper tape and possibly an insulator, this device can be mounted to any pair of tweezers. It’s a simple tool, yes, but that’s the beauty of it, and makes for a great entry into the Hackaday Prize

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