The Hoarder’s Dilemma Hack Chat

December 4, 2023 by Dan Maloney 31 Comments

Join us on Wednesday, December 6 at noon Pacific for the The Hoarder’s Dilemma Hack Chat with Gabe Emerson!

There’s a lot to be said for the power of a well-stocked junk bin. It’s almost a magical thing, being able to dive into a random box and retrieve just the right part to perform a needful repair or to complete a project without the need to hit the web or hop in the car for a trip to the hardware store. For those who pride themselves on their resourcefulness, it can be a heady experience indeed.

But as with everything, such feats of fix-it come at a price. That little squirt of dopamine that comes from having just the right thing can make your monkey brain fixate on a simple equation: “More stuff is better stuff.” The higher and deeper your stash, the better your chances of having what you need, assuming you can find it, of course. This way lies madness, and perhaps an appearance on a reality TV show.

Is there a better way? It’s hard to say, but we figured it would be a good idea to loop in someone with a lot of experience collecting junk that somehow finds its way into some pretty cool projects. Gabe Emerson runs the popular and aptly named “saveitforparts” channel over on YouTube, and fancies himself an accomplished hoarder. We’d have to agree, given his recent 1,000-mile drive to pick up a used geodesic dome, or his ever-increasing collection of RV satellite dishes, which he somehow puts to good use. His junk collection is pretty epic; he even has a whole piece of property devoted to the larger pieces of his collection, like an entire monorail train. He seems uniquely qualified to discuss the “Hoarder’s Dilemma” and the painful process of deciding what stays and what goes.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, December 6 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

This Laser-Cut One-Piece Wedge Tenon Locks Wood Joints Tight

December 4, 2023 by Dan Maloney 24 Comments

Woodworkers have always been very clever about making strong and attractive joints — think of the strength of a mortise and tenon, or the artistry of a well-made dovetail. These joints have been around for ages and can be executed with nothing more than chisels and a hand saw, plus a lot of practice, of course. But new tools bring new challenges and new opportunities in joinery, like this interesting “hammer joint” that can be made with a laser cutter.

This interesting joint comes to us from [Jiskar Schmitz], who designed it for quick, solid, joints without the need for glue or fasteners. It’s a variation on a wedged mortise and tenon joint, which strengthens the standard version of the joint by using a wedge to expand the tenon outward to make firm contact with the walls of the tenon.

The hammer joint takes advantage of the thin kerf of a laser cutter and its ability to make blind cuts to produce a tenon with a built-in wedge. The wedge is attached to a slot in the tenon by a couple of thin connectors and stands proud of the top of the tenon. The tenon is inserted into a through-hole mortise, and a firm hammer blow on the wedge breaks it free and drives it into the slot. This expands the tenon and locks it tightly into the mortise, creating a fairly bulletproof joint. The video below tells the tale.

While the hammer joint seems mainly aimed at birch plywood, [Jiskar] mentions testing it in other materials, such as bamboo, MDF, and even acrylic, although wood seems to be the best application. [Jiskar] also mentions a potential improvement: the addition of a ratchet and pawl shape between the wedge and the slot in the tenon, which might serve to lock the wedge down and prevent it from backing out.

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Hackaday Links: December 3, 2023

December 3, 2023 by Dan Maloney 28 Comments

Sure, it does less than originally promised, but hey — at least it’s more expensive. That about sums up Tesla fans’ feelings after the long-awaited Cybertruck reveal at the Texas Gigafactory on Thursday, where Elon Musk himself handed over the keys — or their Cyber equivalent — to a few new owners. These are expensive machines — $61,000 for the two-motor model, and just shy of $100,000 for the three-motor all-wheel-drive model with all the bells and whistles. That’s considerably more than they were expected to cost back in 2019, a fact which may be at least partially behind the drop in Tesla shares after the launch.

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Tiny POV Turns Right Round For Volumetric Fun

December 3, 2023 by Dan Maloney 13 Comments

Just when you think the POV thing has run out of gas, along comes [mitxela] to liven things up. In this, he’s taken the whole persistence of vision display concept and literally spun up something very cool: a tiny volumetric “electric candle” display.

As he relates the story, the idea came upon him on a night out at the pub, which somehow led to the idea of an electric candle. Something on the scale of a tea light would fit [mitxela]’s fascination with very small and very interesting circuits, so it was off to the races. Everything needed — motor, LIR2450 coin cell, RP2040, and the vertical matrix of LEDs — fits into the footprint of the motor, which was salvaged from a CD drive. To avoid the necessity of finding or building a tiny slip-ring, he instead fixed everything to the back of the motor and attached its shaft to a Delrin baseplate.

The 8×10 array of surface-mount LEDs stands atop the RP2040 with the help of some enameled magnet wire, itself a minor bit of circuit sculpture. There’s also a 3D-printed holder for a phototransistor and IR LED, which form a sensor to trigger the display; you can see [mitxela] using a finger to turn the display off and move it back and forth. It goes without saying that these things always look better in person than they do in stills or even on video, but we still think it looks fantastic. There’s also a deep dive into generating volumetric data in the write-up, as well as an unexpected foray into the fluid dynamics calculations needed to create a realistic flame effect for the candle.

All in all, this is a fantastic if somewhat fragile project. We love the idea of putting this in a glass enclosure to make it look a little like a Nixie tube, too.

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Simple Chemistry To Metallize And Etch Silicon Chips

December 3, 2023 by Dan Maloney 5 Comments

We’ve been eagerly following [ProjectsInFlight]’s stepwise journey toward DIY semiconductors, including all the ups and downs, false leads, and tedious optimizations needed to make it possible for the average hacker to make chips with readily available tools and materials.

Next up is metallization, and spoiler alert: it wasn’t easy. In a real fab, metal layers are added to chips using some form of deposition or sputtering method, each of which needs some expensive vacuum equipment. [ProjectsInFlight] wanted a more approachable way to lay down thin films of metal, so he turned to an old friend: the silver mirror reaction. You may have seen this demonstrated in high school chemistry; a preparation of Tollen’s reagent, a mix of sodium hydroxide, ammonia, and silver nitrate, is mixed with glucose in a glass vessel. The glucose reduces the reagent, leaving the metallic silver to precipitate on the inside of the glass, which creates a beautiful silvered effect.

Despite some issues, the silvering method worked well enough on chips to proceed on, albeit carefully, since the layer is easily scratched off. [ProjectsInFlight]’s next step was to find an etchant for silver, a tall order for a noble metal. He explored piranha solutions, which are acids spiked with peroxide, and eventually settled on plain old white vinegar with a dash of 12% peroxide. Despite that success, the silver layer was having trouble sticking to the chip, much preferring to stay with the photoresist when the protective film was removed.

The solution was to replace the photoresist’s protective film with Teflon thread-sealing tape. That allowed the whole process from plating to etching to work, resulting in conductive traces with pretty fine resolution. Sure they’re a bit delicate, but that’s something to address another day. He’s come a long way from his DIY tube furnace used to put down oxide layers, and suffering through the search for oxide etchants and exploring photolithography methods. It’s been a fun ride so far, and we’re eager to see what’s next.

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Hackaday Podcast Episode 246: Bypassing Fingerprint Readers Is Easy, Killing Memory Chips Is Hard, Cell Phones Vs Sperm

December 1, 2023 by Dan Maloney No comments

It’s the week after Thanksgiving (for some of us) and if you’re sick of leftovers, you’re in luck as Elliot and Dan get together to discuss the freshest and best inter-holiday hacks. We’ll cue up the “Mission: Impossible” theme for a self-destructing flash drive with a surprising sense of self-preservation, listen in on ET only to find out it’s just a meteor, and look for interesting things to do with an old 3D printer. We’ll do a poking around a little in the basement at Tektronix, see how easy it is to spoof biometric security, and get into a love-hate relationship with both binary G-code and bowling balls with strings attached. What do you do with a box full of 18650s? Easy — make a huge PCB to balance them the slow way. Is your cell phone causing a population crisis? Is art real or AI? And what the heck is a cannibal CME? Tune in as we dive into all this and more.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Grab a copy for yourself if you want to listen offline.

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Retrotechtacular: Studio Camera Operation, The BBC Way

November 26, 2023 by Dan Maloney 11 Comments

If you ever thought that being a television camera operator was a simple job, this BBC training film on studio camera operations will quickly disabuse you of that notion.

The first thing that strikes you upon watching this 1982 gem is just how physical a job it is to stand behind a studio camera. Part of the physicality came from the sheer size of the gear being used. Not only were cameras of that vintage still largely tube-based and therefore huge — the EMI-2001 shown has four plumbicon image tubes along with tube amplifiers and weighed in at over 100 kg — but the pedestal upon which it sat was a beast as well. All told, a camera rig like that could come in at over 300 kg, and dragging something like that around a studio floor all day under hot lights had to be hard. It was a full-body workout, too; one needed a lot of upper-body strength to move the camera up and down against the hydropneumatic pedestal cylinder, and every day was leg day when you had to overcome all that inertia and get the camera moving to your next mark.

Operating a beast like this was not just about the bull work, though. There was a lot of fine motor control needed too, especially with focus pulling. The video goes into a lot of detail on maintaining a smooth focus while zooming or dollying, and shows just how bad it can look when the operator is inexperienced or not paying attention. Luckily, our hero Allan is killing it, and the results will look familiar to anyone who’s ever seen any BBC from the era, from Dr. Who to I, Claudius. Shows like these all had a distinctive “Beeb-ish” look to them, due in large part to the training their camera operators received with productions like this.

There’s a lot on offer here aside from the mechanical skills of camera operation, of course. Framing and composing shots are emphasized, as are the tricks to making it all look smooth and professional. There are a lot of technical details buried in the video too, particularly about the pedestal and how it works. There are also two follow-up training videos, one that focuses on the camera skills needed to shoot an interview program, and one that adds in the complications that arise when the on-air talent is actually moving. Watch all three and you’ll be well on your way to running a camera for the BBC — at least in 1982.

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