Author: Al Williams

4468 Articles

Bend It Like A Carpenter

January 24, 2023 by 18 Comments

We’ve always known, in theory, there are ways to bend wood, but weren’t really clear on how it worked. Now that we’ve seen [Totally Handy]’s recent video, we’ve learned a number of tricks to pull it off. Could we do any of them? Probably not, any more than watching someone solder under a microscope means you could do it yourself with no practice. But it sure made us want to try!

All of the techniques involve either water or steam, but we were fascinated with the cuts that make the wood almost into a flexible mesh. There are several tricks you can pick up, too, if you watch carefully. In “wordless workshop” form, there’s no real audio or text, just watching this guy make some really interesting wood pieces.

It looks like you could do some of this with pretty ordinary tools, although he does use a table saw, a router, and a few types of sanders. There isn’t anything too exotic, although we weren’t entirely clear on how the steam tube worked. If you have a cheap CNC machine, those usually can do a pretty good job on wood, and we wondered if you couldn’t pull off some of these tricks that way, too.

We love projects made with wood that look like they were impossible to make. Don’t forget wood as a construction material. Combined with 3D printing and other techniques, it can make some impressive things.

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Arduino Is Out To (Rocket) Launch

January 23, 2023 by 8 Comments

It looks like an ordinary toolbox, but when you open up the Arduino Launch Control System, you’ll find a safe method for triggering model rocket launches. The system uses two separate power supplies. Both must be on for a successful launch and one requires a key. To trigger a 10-second countdown, the operator must hold down two buttons. Releasing either button will stop the countdown.

Besides safety, the controller tracks mission elapsed time and can read weather information from a few sensors. A good-looking build and we like the idea of building inside a toolbox for this sort of thing.

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Listening To A Flashlight — Lunar Flashlight

January 23, 2023 by 4 Comments

If you’ve been looking for a practical example of using GNU Radio, you should check out [Daniel Estévez’s] work on decoding telemetry captured from the Lunar Flashlight cubesat. The cubesat is having some trouble, but the data in question was a recording from the day after launch. We aren’t sure what it would take to eavesdrop on it live, but the 3-minute recording is from a 20-meter antenna at 8.4 GHz.

The flowgraph for GNU Radio isn’t as bad as you might think, thanks to some judicious reuse of blocks from other projects to do some of the decoding. The modulation is PCM/PM/bi-phase-L. Nominally, the speed is supposed to be 48,000 baud, but [Daniel] measured 48,077.

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Smiling ad family with 3D printer

Ask Hackaday: Do Kids Need 3D Printers?

January 23, 2023 by 72 Comments

Mattel holds a fond place in most people’s hearts as they made many of the toys we played with as kids. You might remember the Thingmaker, which was essentially an Easy Bake Oven with some goop and molds that let you make rubbery creatures. But back in 2016, Mattel had an aborted attempt to bring 3D printing to kids under the Thingmaker label. You can see a promo video of the device below. You might not have seen one in real life, though. The product was delayed and eventually canceled. Even so, we frequently see press releases for “kids printers” and we’ve been wondering, should this be a thing? Continue reading “Ask Hackaday: Do Kids Need 3D Printers?” →

PCB Pen Holder Is Over The Top

January 22, 2023 by 6 Comments

Like most of us, [Arnov] used a spare coffee mug to hold pens on his desk. But there has to be a better way, right? Surely if you build a better mouse trap… or, in this case, a pen holder. He’d be the first to admit that he might have gotten a little carried away, but the result is an attractive pen holder made from PCB material, one of which is actually an active circuit board.

The pen holder has some power management, as there’s a rechargeable battery that allows it to charge devices such as a smartphone or an embedded board. The power is also available for LEDs in the pen holder. The PCBs are bound together with 3D printed brackets.

The non-functioning PCBs still have patterns etched to make them more interesting looking. This is one of those things that isn’t technically a big deal, but we really liked the look of it, which was quite professional. We’ve seen PCBs used as enclosures before, but making the pattern and improving light transmission by removing the solder mask were nice touches.

If you don’t like the idea of making enclosures from PCB material, don’t forget they can form other components, as well. Clever arrangements can build resistors, capacitors, and inductors not to mention exotic transmission line elements.

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Floppy Photog: Making An IR Filter From A 3.5″ Disk

January 21, 2023 by 15 Comments

Sony used to sell digital cameras that recorded on actual floppy disks. We’ve come a long way, but [Mathieu] put a floppy in a digital camera recently for an entirely different reason. First, though, he had to modify the camera to work on the full spectrum, something he covered in an earlier video. You can see both videos, below.

As you might expect, he didn’t actually put an entire floppy inside the camera. He used the internal disk portion as an infrared filter to obtain some striking photos. In all honestly, the results were not as nice as what you get from a very expensive professional filter. But the pictures looked great and the difference was not as much as you’d expect compared to the cost difference.

The real work, though, is converting the camera to full spectrum as seen in the second video. A normal camera has an IR filter to prevent the sensor from seeing IR light. This prevents the image sensor from capturing things your eyes don’t see. The modification replaces the filter with a clear filter.

We’ve covered this kind of conversion before. You can even do it with a Raspberry Pi, if you like.

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Q Meter Measures… Q, Of Course

January 19, 2023 by 20 Comments

If you’ve ever dealt with RF circuits, you probably have run into Q — a dimensionless number that indicates the ratio of reactance to resistance. If you ever wanted to measure Q, you could do worse than pick up a vintage Boonton 160A Q meter. [Mikrowave1] did just that and shows us how it works in the video below.

Most often, the Q is of interest in an inductor. A perfect inductor would have zero resistance and be all reactance. If you could find one of those, it would have an infinite Q because you divide the reactance by the resistance. Of course, those inductors don’t exist. You can also apply Q to any circuit with reactance and the video talks about how to interpret Q for tuned circuits. You can also think of the Q number as the ratio of frequency to bandwidth or the dampening in an oscillator. A versatile measurement, indeed.

It sounds as though you could just measure the resistance of a coil and use that to compute Q. But you really need to know the total loss, and that’s not all due to resistance. A meter like the 160A uses a signal generator and measures the loss through the circuit.

The best part of the video is the teardown, though. This old tube gear is oddly beautiful in a strange sort of way. A real contrast to the miniaturized circuits of today. The Q meter is one of those nearly forgotten pieces of gear, like a grid dip oscillator. If you need to wind your own coils, by the way, you could do worse than see how [JohnAudioTech] does it.

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