Repairing A 300W CO2 Laser, One Toasted Part At A Time

A couple months back, [macona] got his hands on a 300 watt Rofin CO2 laser in an unknown condition. Unfortunately, its condition became all too known once he took a peek inside the case of the power supply and was confronted with some very toasty components. It was clear that the Magic Smoke had been released with a considerable bit of fury, the trick now was figuring out how to put it back in.

The most obvious casualty was an incinerated output inductor. His theory is that cracks in the ferrite toroid changed its magnetic properties, ultimately causing it to heat up during high frequency switching. With no active cooling, the insulation cooked off the wires and things started to really go south. Maybe. In any event, replacing it was a logical first step.

If you look closely, you may see the failed component.

Unfortunately, Rofin is out of business and replacement parts weren’t available, so [macona] had to wind it himself with a self-sourced ferrite and magnet wire. Luckily, the power supply still had one good inductor that he could compare against. After replacing the coil and a few damaged ancillary wires and connectors, it seemed like the power supply was working again. But with the laser and necessary cooling lines connected, nothing happened.

A close look at the PCB in the laser head revealed that a LM2576HVT switching regulator had exploded rather violently. Replacing it wasn’t a problem, but why did it fail to begin with? A close examination showed the output trace was shorted to ground, and further investigation uncovered a blown SMBJ13A‎ TVS diode. Installing the new components got the startup process to proceed a bit farther, but the laser still refused to fire. Resigned to hunting for bad parts with the aid of a microscope, he was able to determine a LM2574HVN voltage regulator in the RF supply had given up the ghost. [macona] replaced it, only for it to quickly heat up and fail.

This one is slightly less obvious.

Now this was getting ridiculous. He replaced the regulator again, and this time pointed his thermal camera at the board to try and see what else was getting hot. The culprit ended up being an obsolete DS8922AM dual differential line transceiver that he had to source from an overseas seller on eBay.

After the replacement IC arrived from the other side of the planet, [macona] installed it and was finally able to punch some flaming holes with his monster laser. Surely the only thing more satisfying than burning something with a laser is burning something with a laser you spent months laboriously repairing.

We love repairs at Hackaday, and judging by the analytics, so do you. One of this month’s most viewed posts is about a homeowner repairing their nearly new Husqvarna riding mower instead of sending it into get serviced under the warranty. Clearly there’s something about experiencing the troubleshooting and repair process vicariously, with our one’s own hardware safely tucked away at home, that resonates with the technical crowd.

Sunlight-Based Life Clock Predicts Your Darkest Hour

The past year has been quite a ride for everyone on Earth. But you never know which day is going to be your last, so you might as well live a little, eh? This clock doesn’t actually know when you’ll kick off, either. But just for fun, it predicts the number of years remaining until you go to that hackerspace in the sky by hazarding a guess that’s based on your current age and the latest life expectancy tables. Don’t like the outcome? It’s completely randomized, so just push the button and get a set of numbers: the age you might die, and the percentage of life elapsed and remaining.

We love the design of this calculated doom clock, and it’s quite simple inside — an Arduino Pro Mini outputs the graph on an 2.9″ e-paper display, and both are powered with a 5.5 V solar panel. Just suction cup that puppy to the window and you’ll get automatic updates about your impending demise on sunny days, and none on cloudy days.

Want a more realistic picture of your mortality? Here’s a clock that counts down to your 80th birthday.

The Other First Computer: Konrad Zuse And The Z3

Bavarian Alps, Dec. 1945:

Since 1935, Berlin engineer Konrad Zuse has spent his entire career developing a series of automatic calculators, the first of their kind in the world: the Z1, Z2, Z3, S1, S2, and Z4. He accomplished this with a motley group of engineers, technicians, and mathematicians who were operating against all odds. With all the hardships and shortages of war and the indifference of their peers, the fact that they succeeded at all is a testament to their dedication and resourcefulness. And with the end of the war, more hardships have been piling on.

Two years ago, during the Battle of Berlin, bombers completely destroyed the Zuse family home and adjacent workshops on the Methfesselstraße, where they performed research and fabrication. All of the calculators, engineering drawings, and notes were lost in the rubble, save for the new Z4 nearing completion across the canal in another workshop on Oranienstraße. In the midst of all this, Zuse married in January of this year, but was immediately plunged into another crisis when the largest Allied air raid of the war destroyed the Oranienstraße workshop in February. They managed to rescue the Z4 from the basement, and miraculously arranged for it to be shipped out of the Berlin. Zuse, his family, and colleagues followed soon thereafter. Here and there along the escape route, they managed to complete the final assembly and testing of the Z4 — even giving a demonstration to the Aerodynamics Research Institute in Göttingen.

On arrival here in the Bavarian Alps, Zuse found a ragtag collection of refugees, including Dr Werner Von Braun and a team of 100 rocket scientists from Peenemünde. While everyone here is struggling just to stay alive and find food and shelter, Zuse is further worried with keeping his invention safe from prying eyes. Tensions have risen further upon circulation of a rumor that an SS leader, after three bottles of Cognac, let slip that his troops aren’t here to protect the scientists but to kill them all if the Americans or French approach.

In the midst of all this madness, Zuse and his wife Gisela welcomed a baby boy, and have taken up residence in a Hinterstein farmhouse. Zuse spends his time working on something called a Plankalkül, explaining that it is a mathematical language to allow people to communicate with these new machines. His other hobby is making woodblocks of the local scenery, and he plans to start a company to sell his devices once the economy recovers. There is no doubt that Konrad Zuse will soon be famous and known around the world as the father of automatic computers. Continue reading “The Other First Computer: Konrad Zuse And The Z3”

Printable Hot-Swap Sockets Make Keyboard Building Even Cooler

Okay, so you want to build a keyboard — something crazy-curvy like the dactyl or dactyl manuform. The kind of keyboard that has to be hand-wired, because key wells and rigid PCBs do not play well together. You want to build this keyboard, but all that hand-wiring would mean that you can’t easily swap switches later. And it will means hours and hours of fiddly soldering. What do you do? You could buy or design your own switch PCBs, but again, those are rigid and space is limited inside of most of these designs.

If you’re [stingray127], you trade those hours of soldering for a week of designing and printing some sweet little hot-swap sockets with wire guides. This is version four, which is easier to print than earlier versions. They are designed to use through-hole diodes and 24 AWG solid-core wire and give a tight fit. Can’t figure out how to use them? [stingray127] has a wiring guide with plenty of pictures.

We really like this idea, and it makes the end result feel more like a totally hand-wired keyboard than individual switch PCBs would As you can see, it involves little solder. The only downside is that you can only swap a few switches at a time, otherwise the matrix might fall apart. But that’s hardly even a downside.

Just want to make a macropad? You can easily print your way out of using a PCB for those, too.

Via KBD and r/mk

Review: Battery Spot Welders, Why You Should Buy A Proper Spot Welder

Making battery packs is a common pursuit in our community, involving spot-welding nickel strips to the terminals on individual cells. Many a pack has been made in this way, using reclaimed 18650 cells taken from discarded laptops. Commercial battery spot welders do a good job but have a huge inrush current and aren’t cheap, so it’s not uncommon to see improvised solutions such as rewound transformers taken out of microwave ovens. There’s another possibility though, in the form of cheap modules that promise the same results using a battery pack as a power supply.

With a love of putting the cheaper end of the global electronic marketplace through its paces for the entertainment of Hackaday readers I couldn’t resist, so I parted with £15 (about $20), for a “Mini Spot Welder”, and sat down to wait for the mailman to bring me the usual anonymous grey package.

Continue reading “Review: Battery Spot Welders, Why You Should Buy A Proper Spot Welder”

Modular Box Design Eases Silicone Mold-Making

Resin casting is a fantastic way to produce highly detailed parts in a wide variety of colors and properties, and while the process isn’t complicated, it does require a certain amount of care and setup. Most molds are made by putting a part into a custom-made disposable box and pouring silicone over it, but [Foaly] was finding the process of making and re-making those boxes a bit less optimized than it could be. That led to this design for a re-usable, modular, adjustable mold box that makes the workflow for small parts considerably more efficient.

The walls of the adjustable box are four identical 3D-printed parts with captive magnets, and the base of the box is a piece of laser-cut steel sheet upon which the magnetic walls attach. The positioning and polarity of the magnets are such that the box can be assembled in a variety of sizes, and multiple walls can be stacked to make a taller mold. To aid cleanup and help prevent contamination that might interfere with curing, the inner surfaces of each piece are coated in Kapton tape.

The result is a modular box that can be used and re-used, and doesn’t slow down the process of creating and iterating on mold designs. The system as designed is intended for small parts, but [Foaly] feels there is (probably) no reason it can’t be scaled up to some degree. Interested? The design files are available from the project’s GitHub repository, and if you need to brush up a bit on how resin casting works, you can read all about it here.

An Automatic Shop Vac Dust Extractor

Finding cheap or even free tools in the second-hand adverts is probably a common pursuit among Hackaday readers. Thus many of you will like [DuctTape Mechanic], have a row of old woodworking bench tools. The experience we share with him is a lack of dust extraction, which makes his adaption of a second-hand shop vac as an automatic dust extractor for his chop saw worth a watch. Take a look, we’ve put the video below the break!

The system hooks up a relay coil to the saw’s on/off switch, which controls the vacuum’s power. It’s thus not the most novel of hacks, but there are a few things to be aware of along the way and who among us doesn’t like watching a bit of gentle progress on a workshop project? The 120V current taken by both vacuum and saw sound excessive to those of us used to countries with 230V electricity, but the relay is chosen to easily serve that load. What’s nice about the automatic system is that being at the bench is not accompanied by the constant deafening noise of the shop vac, and save for when the saw is in use the bench is both dust-free and mercifully quiet.

If you happen to have a solid state relay in your parts bin, here’s another way to achieve a similar result.

Continue reading “An Automatic Shop Vac Dust Extractor”