Solar Panel Keeps Cheap Digital Calipers Powered Up

April 20, 2024 by Dan Maloney 40 Comments

There’s no doubt that cheap digital calipers are useful, especially when designing 3D-printed parts. Unfortunately, cheap digital calipers are also cheap, and tend to burn through batteries quickly. Sure, you can remove the battery when you’re done using them, but that’s for suckers — winners turn to solar power to keep their calipers always at the ready.

[Johan]’s solar upgrade begins with, unsurprisingly, a solar cell, one that just fits on the back of his digital calipers. Like most of these cheap calipers, this one is powered by a single 1.5 V LR44 button cell, while the polycrystalline solar cell is rated for 5 V, so [Johan] used a red LED as a crude voltage regulator. He also added a stack of fourteen 100 μF SMD capacitors soldered together in parallel. The 1206 devices form a 1,400 μF block that’s smaller than the original button cell so that everything fits in the vacated battery compartment. It’s pretty slick.

Given their agreeable price point, digital calipers are a tempting target for hacking. We’ve seen a ton of them, from accessibility add-ons to WiFi connectivity and even repurposing them for use as DROs. Ever wonder how these things work? We’ve looked at that, too.

Hacked Oscilloscope Plays Breakout, Hints At More

April 18, 2024 by Dan Maloney 8 Comments

You know things are getting real when the Dremel is one of the first tools you turn to after unboxing your new oscilloscope. But when your goal is to hack the scope to play Breakout, sometimes plastic needs to be sacrificed.

Granted, the scope in question, a Fnirsi DSO152, only cost [David Given] from Poking Technology a couple of bucks. And while the little instrument really isn’t that bad inside, it’s limited to a single channel and 200 kHz of bandwidth, so it’s not exactly lab quality. The big attractions for [David] were the CH32F103 microcontroller and the prominent debug port inside, not to mention the large color LCD panel.

[David]’s attack began with the debug port and case mods to allow access, but quickly ground to a halt when he accidentally erased the original firmware. But no matter — tracing out the pins is always an option. [David] made that easier by overlaying large photos of both sides of the board, which let him figure out which buttons went to which pins, and mapping for the display’s parallel interface. He didn’t mess with any of the analog stuff except to create a quick “Hello, oscilloscope!” program to output a square wave to the calibration pin. He did, however, create a display driver and port a game of breakout to the scope — video after the hop.

We’ve been seeing a lot of buzz around the CH32xx MCUs lately; seeing it start to show up in retail products is perhaps a leading indicator of where the cheap RISC chips are headed. We’ve seen a few interesting hacks with them, but we’ve also heard tell they can be hard to come by. Maybe getting one of these scopes to tear apart can fix that, though.

Continue reading “Hacked Oscilloscope Plays Breakout, Hints At More” →

More Microwave Metal Casting

April 16, 2024 by Dan Maloney 10 Comments

If you think you can’t do investment casting because you don’t have a safe place to melt metal, think again. Metal casting in the kitchen is possible, as demonstrated by this over-the-top bathroom hook repair using a microwave forge.

Now, just because it’s possible doesn’t mean it’s advisable. There are a lot better ways to fix something as mundane as a broken bathroom hook, as [Denny] readily admits in the video below. But he’s been at the whole kitchen forging thing since building his microwave oven forge, which uses a special but easily constructed ceramic heat chamber to hold a silicon carbide crucible. So casting a replacement hook from brass seemed like a nice exercise.

The casting process starts with a 3D-printed model of the missing peg, which gets accessories such as a pouring sprue and a thread-forming screw attached to it with cheese wax. This goes into a 3D-printed mold which is filled with a refractory investment mix of plaster and sand. The green mold is put in an air fryer to dry, then wrapped in aluminum foil to protect it while the PLA is baked out in the microwave. Scrap brass gets its turn in the microwave before being poured into the mold, which is sitting in [Denny]’s vacuum casting rig.

The whole thing is over in seconds, and the results are pretty impressive. The vacuum rig ensures metal fills the mold evenly without voids or gaps. The brass even fills in around the screw, leaving a perfect internal thread. A little polishing and the peg is ready for bathroom duty. Overly complicated? Perhaps, but [Denny] clearly benefits from the practice jobs like this offer, and the look is pretty cool too. Still, we’d probably want to do this in the garage rather than the kitchen.
Continue reading “More Microwave Metal Casting” →

Retrotechtacular: The Other Kind Of Fallout Show

April 16, 2024 by Dan Maloney 29 Comments

Thanks to the newly released Amazon Prime series, not to mention nearly 30 years as a wildly successful gaming franchise, Fallout is very much in the zeitgeist these days. But before all that, small-F fallout was on the minds of people living in countries on both sides of the Iron Curtain who would have to deal with the aftermath of a nuclear exchange.

“Uwaga! Pył promieniotwórczy“ (“Beware! Radioactive Dust”) is a 1965 Polish civil defense film from film studio Wytwórnia Filmów Oświatowych. While the Cold War turning hot was not likely to leave any corner of the planet unscathed, Poland was certainly destined to bear the early brunt of a nuclear exchange between the superpowers, and it was clear that the powers that be wanted to equip any surviving Polish people with the tools needed to deal with their sudden change in circumstances.

The film, narrated in Polish but with subtitles in English, seems mainly aimed at rural populations and is mercifully free of the details of both fallout formation and the potential effects of contact with radioactive dust, save for a couple of shots of what looks like a pretty mild case of cutaneous radiation syndrome.

Defense against fallout seems focused on not inhaling radioactive dust with either respirators or expedient facemasks, and keeping particles outside the house by wearing raincoats and boots, which can be easily cleaned with water. The fact that nowhere in the film is it mentioned that getting fallout on your clothes or in your lungs could be largely avoided by not going outside is telling; farmers really can’t keep things running from the basement.

A lot of time in this brief film is dedicated to preventing food and water from becoming contaminated, and cleaning it off if it does happen to get exposed. We thought the little tin enclosures over the wells were quite clever, as were the ways to transfer water from the well to the house without picking up any contamination. The pros and cons of different foods are covered too — basically, canned foods dobry, boxed foods zły. So, thumbs up for Cram, but you might want to skip the YumYum deviled eggs.

Dealing with the potential for a nuclear apocalypse is necessarily an unpleasant subject, and it’s easy to dismiss the advice of the filmmakers as quaint and outdated, or just an attempt to give the Polish people a sense of false hope. And that may well be, but then again, giving people solid, practical steps they can take will at least give them some agency, and that’s rarely a bad thing.

Continue reading “Retrotechtacular: The Other Kind Of Fallout Show” →

Hackaday Links: April 14, 2024

April 14, 2024 by Dan Maloney 10 Comments

The Great American Eclipse v2.0 has come and gone, sadly without our traveling to the path of totality as planned; family stuff. We did get a report from friends in Texas that it was just as spectacular there as expected, with the bonus of seeing a solar flare off the southwest limb of the disk at totality. Many people reported seeing the same thing, which makes us a bit jealous — OK, a lot jealous. Of course, this presented an opportunity to the “Well, ackchyually” crowd to point out that there were no solar flares or coronal mass ejections at the time, so what people saw wasn’t an exquisitely timed and well-positioned solar flare but rather a well-timed and exquisitely positioned solar prominence. Glad we cleared that up. Either way, people in the path of totality saw the Sun belching out gigatons of plasma while we had to settle for 27% totality.

Continue reading “Hackaday Links: April 14, 2024” →

Vintage Particle Counter Is A Treasure Trove Of Classic Parts

April 13, 2024 by Dan Maloney 1 Comment

If you need a demonstration of just how far technology has come in the last 40 years, just take a look at this teardown of a 1987 laser particle counter.

Granted, the laser-powered instrument that [Les Wright] scored off of eBay wasn’t exactly aimed at consumers. Rather, this was more likely an instrument installed in cleanrooms to make sure the particulate counts didn’t come out of range. As such, it was built like a battleship in a huge case stuffed with card after card of electronics, along with the attendant pumps and filters needed to draw in samples. But still, the fact that we can put essentially the same functionality into a device that easily fits in the palm of your hand is pretty striking.

[Les] clearly bought this instrument to harvest parts from it, and there’s a ton of other goodness inside, including multiple copies of pretty much every chip from the Z80 family. The analog section has some beautiful Teledyne TP1321 op-amps in TO-99 cans. Everything is in immaculate condition, and obsolete or not, this is an enviable haul of vintage parts, especially the helium-neon laser at its heart, which still works. [Les] promises an in-depth look at that in a follow-up video, but for now, he treats us to a little tour of the optics used to measure particulates by the amount of laser light that’s scattered.

All things considered, [Les] really made out well on this find — much better than his last purchase.

Continue reading “Vintage Particle Counter Is A Treasure Trove Of Classic Parts” →

Electromagnets Make Vertical CNC Cutter A Little Stickier

April 12, 2024 by Dan Maloney 12 Comments

Workholding is generally not a problem on a big CNC plasma cutter.; gravity does a pretty good job of keeping heavy sheet steel in place on the bed. But what if your CNC table isn’t a table? The answer: magnets — lots of magnets.

The backstory on this is a bit involved, but the condensed version is that [Lucas] needed a CNC plasma cutter big enough to cut full-sized sheets of steel, but lacked the floor space in his shop for such a beast. His solution was to build a custom CNC machine that stands more or less vertically, allowing him to cut full sheets in a mere fraction of the floor space. It’s a fantastic idea, one that he put a lot of effort into, but it’s not without its problems. Chief among them is the tendency for the sheet metal to buckle and bulge during cutting since gravity isn’t working for him, along with the pesky problem of offcuts slipping away.

To help hold things in place, [Lucas] decided to magnetize the bed of his cutter. That required winding a bunch of magnets, which is covered in the video below. Mass production of magnets turns out not to be as easy as you’d think. Also unexpected was the need to turn off magnets when the cutting torch is nearby, lest the magnetic field bork the cutting plasma. [Lucas] grabbed some code from the LinuxCNC forum that streams the gantry coordinates over serial and used an Arduino to parse those messages. When the torch is getting close to one of the magnets, a relay board cuts power to just that magnet. You can see it in action in the video below; at around the 18:15 mark, you can see the sheet bulging up a bit when the torch comes by, and sucking back down when it moves on.

The amount of work [Lucas] put into this project is impressive, and the results are fantastic. This isn’t the first time he’s relied on the power of magnets to deal with sheet steel, and it probably won’t be the last.

Continue reading “Electromagnets Make Vertical CNC Cutter A Little Stickier” →