Link Trucker Is A Tiny Networking Giant

January 22, 2016 by Elliot Williams 17 Comments

If you’re a networking professional, there are professional tools for verifying that everything’s as it should be on the business end of an Ethernet cable. These professional tools often come along with a professional pricetag. If you’re just trying to wire up a single office, the pro gear can be overkill. Unless you make it yourself on the cheap! And now you can.

[Kristopher Marciniak] designed and built an inexpensive device that verifies the basics:

Is the link up? Is this cable connected?
Can it get a DHCP address?
Can it perform a DNS lookup?
Can it open a webpage?

What’s going on under the hood? A Raspberry Pi, you’d think. A BeagleBoard? Our hearts were warmed to see a throwback to a more civilized age: an ENC28J60 breakout board and an Arduino Uno. That’s right, [Kristopher] replicated a couple-hundred dollar network tester for the price of a few lattes. And by using a pre-made housing, [Kristopher]’s version looks great too. Watch it work in the video just below the break.

Building an embedded network device used to be a lot more work, but it could be done. One of our favorites is still [Ian Lesnet’s] webserver on a business card from way back in 2008 which also used the ENC28J60 Ethernet chip.
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Solderless Breadboard Parasitics

January 19, 2016 by Al Williams 42 Comments

Solderless breadboards are extremely handy. You always hear, of course, that you need to be careful with them at high frequencies and that they can add unwanted capacitance and crosstalk to a circuit. That stands to reason since you have relatively long pieces of metal spaced close together — the very definition of a capacitor.

[Ryan Jensen] did more than just listen to that advice. He built a circuit and used a scope to investigate just how much coupling he could expect with a simple digital circuit. Better still, he also made a video of it (see below). The test setup shows a single gate of a hex Schmitt trigger inverter with a sine wave input. The output transitions ring and also couple back into the input.

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What’s In A Tool? A Case For Made In USA.

January 18, 2016 by Gerrit Coetzee 253 Comments

A lot of people make the argument that you can’t go wrong buying a tool made in USA, Germany, Japan, Switzerland, etc. They swear that any Chinese tool will be garbage and it’s not worth purchasing them. Now, any discerning mind will say, “Wait a minute, why? China has a huge economy, experienced people, and the ability to use all the scary chemicals that make the best steel. Why would their tools be any better or worse than ours?” It’s a very valid argument. There are lots of Chinese tools that are the best in the world. Most of what we see in our stores are not. So what is the difference. Why does a country who can make the best tools not make the best tools? Surely it isn’t purely cost cutting. Is it cultural? The opinion I wish to put forth is that it’s a matter of design intent communication.

I’ve worked as an engineer in industry. The one common thread between a quality product and a bad product has always been this, ”Is the person who designed the product involved in making the product?” If the person or peoples who imbued the design intent into the original product are actively involved in and working towards the execution of that product, that product has a vastly greater chance of being good. Or in other words: outsourcing doesn’t produce a bad product because the new people making the product don’t care. It makes a bad product because the people who understand the intent behind the product are separated from its execution.

As you can see the export made crescent wrench is not made to the same tolerances as the previous wrench.

Let’s take the Crescent wrench as an example. Crescent wrenches used to be made in USA. In the past few years they have begun to make them in China. We can spot many visual differences right away. The new Crescent wrench has a different shape, the logo has changed and the stamping for the logo is dodgy, and worse, the tool just doesn’t operate as well as it used to. The jaws aren’t as hard and they wiggle more. What happened? How could Crescent mess up their flagship so badly. Surely they intended just to cut costs, not to reduce quality. This isn’t shameful in itself

What happened to the Crescent wrench is easily explained by anyone who has seen a product from design to execution before. A factory in the USA set out to make a good adjustable wrench. Hundreds of engineers and employees worked in a building to make a good wrench. When their machines didn’t work, they came up with solutions. When their quality was lacking, they implemented better processes. They had a list of trusted suppliers. They could guarantee that the materials that came in would be imbued with their vision and intent when the product came out. The intent and will of all those people built up in one place over time.

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Recursive Soldering Iron Hacking

January 17, 2016 by Rud Merriam 39 Comments

We’ve all done it. You’re walking out the door or maybe you’ve even gotten on the road when the question hits, “Did I leave the [coffee pot | stove | hair curler | soldering iron ] on?” [Daniel Johnson’s] problem was even worse. He couldn’t tell if his Hakko-936 soldering iron was off because the LED indicator wasn’t always on. Instead it flashed. He fixed that problem and along the way hacked his battery powered soldering iron since he was out of batteries. Now that’s perseverance.

Hacked Soldering Iron to Hack Soldering Iron — Soldering Iron Hack Recursion

The Hakko’s LED turned on whenever the power turned on to heat the tip. That was about every 5 seconds once the tip was hot. But just as a watched pot never boils, a watched LED never seems to flash. After determining the LED was driven by a comparator he decide to unsolder it as part of his hack. He wisely decided using the Hakko on itself was not a good idea so reached for the battery-powered portable iron, which was sadly battery-free. Undaunted, he wired the portable to a power supply and when 4.5 volts didn’t melt the solder cranked it up to 6 volts.

Back to the Hakko, he replaced the red LED with a RBG LED but used only the red and green leads. The green was tied to the 24v power supply through a hefty 47k ohm resistor, and the red was tied to the comparator. A little masking tape to hold things in place and provide insulation finished the job. Now when the Hakko is on the green LED is lit and the red LED shows the heating cycle. Quite clever.

Rehabbing An Historic Tool From Champion Blower And Forge Co.

January 15, 2016 by Mike Szczys 23 Comments

Here’s a tale that warms our hearts. [Gord] is helping out the local living-history museum by rehabbing a historic woodworking tool that they want to add to their live demo woodshop. It’s a hundred-year-old manual drill press that has seen a ton of use.

There are three things that [Gord] has going for him. First off, the Champion Blower and Forge Co. built them to last. Second, he’s not really working on a deadline; the museum doesn’t need it back until May. And third, [Gord] has the tools he needs to do this right.

After cleaning and blasting [Gord] gets down to the really interesting repairs. First off, it wouldn’t be a drill press if someone hadn’t tried to drill through the table at some point. TIG welding filled it up and some milling brought it back. This same method was used again to make a beautiful custom replacement ACME rod. Throwing in a custom bushing replacement, turned wooden handle, and a several other fabricated parts, and [Gord] had the press working again. Check out the mechanism in the video below that shows the crank action turns the bit and a cam advances it through the work piece.

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Desolder DIP Packages Like A Pro

January 12, 2016 by George Graves 55 Comments

Looking for a quick way to desolder those pesky DIP chips? Check out this handy little tip in the video after the break. [Clay Cowgill] shows you the easy way to do it.

Normally, before you desolder a Dual In-line Package (DIP) chip, you have a decision to make: Are you interested in saving the chip or the PCB? The repeated cycles of heating and reheating the PCB while using solder wick, or even a “solder sucker”, can cause a real problem for the PCB. You run the risk of delamination of the PCB traces. Some phenolic based PCBs can barely handle one extra heat cycle, while as a top-quality PCB might be fine with 4 or even 6 rework attempts – but we’ve lifted off tracks with less. And all that thermal stress isn’t exactly the best thing for the chip itself. You risk ending up with a dud.

The other trick commonly used is to cut the pins of the DIP and then you can treat each pin as a single through hole part – and that is generally less aggressive to the PCB, there by saving your board, but destroying the chip.

In the video [Clay Cowgill] is using a Hakko 850 hot air rework station to desolder parts from an Atari 130EX motherboard. He’s able to effortlessly remove the chips, and save the PCB, all without applying and re-applying heat over and over again. That’s something we’ve seen before – the interesting part is where he then uses the air flow to blow the through hole openings clean – making for some of the fastest and cleanest DIP removal we’ve ever seen without using a dedicated desoldering gun.

[Thanks [wblock] via Eevblog]

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Laser Cutting A Bread Knife

January 10, 2016 by James Hobson 19 Comments

What started out as simply a question of whether or not they could… [G2AS] decided to try making a laser cut serrated bread knife — out of plastic.

Now from a distance this may look like they just took their laser cutter and cut out the pattern of a knife, with a jigsaw edge. But no, they actually laser cut a jig which allowed them to cut the serrated edge on an angle, creating an actual sharp edge. It’s quite the setup, but a pretty awesome result. Continue reading “Laser Cutting A Bread Knife” →