3D Printed Zipper Saves the Day!

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[Amr] recently built a 3D printer and came across his first practical application for it — his jacket’s zipper broke!

What we like about this project is [Amr] goes through the entire design process to finished product in his video. He starts by showing us the failed zipper, explaining where and why it failed, and then identifies the design features he needs to keep in order to make a functional replacement. To help accomplish this he checks out the Wikipedia article on zippers which shows an excellent animation of what happens inside of the zipper.

Now confident in his knowledge of all things zipper, he begins to model his replacement using SolidWorks, which is an industry standard among 3D CAD packages — for more information on how to use SolidWorks, we’ve been covering it in our 3D Printering articles! Continue reading “3D Printed Zipper Saves the Day!”

Hacking Dell Laptop Charger Identification

If you’ve ever had a laptop charger die, you know that they can be expensive to replace. Many laptops require you to use a ‘genuine’ charger, and refuse to boot when a knock off model is used. Genuine chargers communicate with the laptop and give information such as the power, current, and voltage ratings of the device. While this is a good safety measure, ensuring that a compatible charger is used, it also allows the manufacturers to increase the price of their chargers.

[Xuan] built a device that spoofs this identification information for Dell chargers. In the four-part series (1, 2, 3, 4), the details of reverse engineering the communications and building the spoofer are covered.

Dell uses the 1-Wire protocol to communicate with the charger, and [Xuan] sniffed the communication using a MSP430. After reading the data and verifying the CRC, it could be examined to find the fields that specify power, voltage, and current.

Next, a custom PCB was made with two Dell DC jacks and an MSP430. This passes power through the board, but uses the MSP430 to send fake data to the computer. The demo shows off a 90 W adapter pretending to run at 65 W. With this working, you could power the laptop from any supply that can meet the requirements for current and voltage.

Replacing a Tire Valve Stem Without Special Tools!

Your car’s tire is losing air from the valve stem — what do you do? Well you could take it to the mechanic and pay upwards of $30 to replace it… or you could try this MacGyver style approach!

Not wanting to take his car to the shop, [David] tried several ways of knocking the tire off its bead. Hitting it with a sledge hammer… Jumping on it… throwing it against the ground… In the end, he realized leverage would be his friend! He’s constructed a tool out of a few pieces of wood — simply place it on the tire near the valve stem, and then drive up the wood with your car. The weight of the car easily compresses the tire leaving you just enough room to pull the tire valve stem out, and put a new one in.

It’s pretty much the same method shops use, they just have a machine to do it for them — because of this, so we don’t think this would hurt your tire. As always though, we’d love to hear what you guys think in the comments! Stick around for the video to see [David’s] process.

Continue reading “Replacing a Tire Valve Stem Without Special Tools!”

Troubleshooting a Broken Power Supply

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How many power bricks have died on you? Have you ever tried to fix them? Sometimes it’s easier to grab another one (they grow on trees right?), but wouldn’t it be nice to save the broken ones from filling up landfills? Depending on the cause of death, it could be a super simple fix!

[Chaim-Leib] recently purchased a powered USB hub that came with a beefy 5v, 4A power supply — it worked great — until 6 months later, when it didn’t. The company sent him a new one, and let him keep the faulty one. Looking for a challenge, [Chaim-Leib] decided to crack it open and see if he could fix it himself.

No burnt caps, no fried diodes, no burn marks anywhere in fact! Luckily he spotted the culprit: One lonely resistor had lifted up from its pad. Having never jostled or dropped the power brick, this failure likely came from some kind of stress formed during original assembly — throw in a bunch of hot and cold thermal changes, and pop goes the solder pad!

It was a simple fix with some solder, and he emailed the company photos of his operation — they’ve promised to send them on to the engineering team to further evaluate the problem.

That was easy.

Oscilloscope Repair Projects Still Probing For Success

lecroy-9450-oscilloscope-repair[Luke] isn’t able to declare total victory yet. His LeCroy 9450 oscilloscope repair project has seen some success, though. The glitchy screen seen above is just one of the problems it had, but has now been fixed. When [Luke] got his hands on it, this was one of three screen states: the other two being normal operation or completely dead. Replacing the screen connector was all it took, so he moved on to the second part.

This one is much less trivial. Only one of the two channels works—which might be the point at which many would abandon the repair—but it’s still a fine single-channel scope. [Luke] continued to trouble-shoot by disassembling the bottom of the case and breaking out the device’s schematics. He traced the circuit and found one module that is suspect (and is looking for help finding a replacement). Unfortunately, the problems don’t end there. Another unknown problem is causing erroneous signals on the displayed waveforms. It’s an odd issue but it really feels like he’s close to solving this one!

The Pioneering Lifestyle in Low Earth Orbit

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Configuration of the International Space Station in May 2011, taken by Space Shuttle Endeavour at the end of the STS-134 mission.

The first element of the International Space Station (ISS) launched over fifteen years ago, on November 20, 1998. For more than thirteen years at least two human beings have been continually living off the surface of our planet. Assembly of the Space Station is now complete. It is being utilized by its crews and scientists from around the world to execute its primary mission – scientific investigations that can only be accomplished in the microgravity environment of Low Earth Orbit (LEO). As with any structure, items age, wear out, or break and need to be repaired. What could be rather “simple” repairs on Earth can become much more complex in zero gravity. In some cases, “necessity becomes the mother of invention.”

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Scooby-Doo Alarm Clock Repair

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This is more of a hack than a repair which is a good reason for me to feature my Scooby-Doo alarm clock repair. I started out trying to simply fix some broken hardware mounts that hold the display and button mechanism within the alarm clock that looks like the Scooby-Doo Mystery Van. During testing I noticed the display was very dim suggesting an unusual current load or other malfunction, plus the alarm was not functional.

One of the coolest features of the alarm was that it made a car honking noise when the alarm was activated. Unfortunately, it turned out that the chip-onboard which produced the honking sound was shorted internally causing some transistor overheating and the dim display. It was impossible to restore functionality of the custom chip-onboard, but lucky for me the data sheets for the LM8560 clock chip revealed that it could directly output a standard alarm beeping sound to a speaker. This required the PCB and some circuitry be configured differently.

In the end the clock’s current load came down to normal parameters, the display was once again bright and the alarm functioned using the standard beeping alarm sound that comes from the LM8560 clock chip. It is sad that the coolness factor of the alarm clock cannot be restored with the honking car sound alarm but my son is quite happy to have his favorite Scooby-Doo alarm clock functioning once again.

The circuit modifications may not have been the cleverest or the best solution, so if you have other suggestions please leave them in the comments below. You can watch the video of the circuit evaluation and repair modifications after the break.

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