Pocket TV Now Shows The Inspection Channel 24/7

August 31, 2020 by Kristina Panos 9 Comments

Those little pocket TVs were quite the cool gadget back in the ’80s and ’90s, but today they’re pretty much useless at least for their intended purpose of watching analog television. (If someone is out there making tiny digital-to-analog converter boxes for these things, please let us know.)

Now that analog pocket TVs are obsolete, they’re finally affordable enough for hacking into a useful tool like an inspection camera. [technichenews] found a nice Casio TV and a suitable analog pinhole camera that also does IR. Since the camera has RCA plugs and the TV’s video input is some long-gone proprietary 3.5mm cable, [technichenews] made a new video-only cable by soldering the yellow RCA wires up to the cable from an old pair of headphones. Power for the camera comes from a universal wall wart set to 12V.

Our favorite part of this project is the way that [technichenews] leveraged what is arguably the most useless part of the TV — the antenna — into the star. Their plan is to use the camera to peer into small engines, so by mounting it on the end of the antenna, it will become a telescoping, ball-jointed, all-seeing eye. You can inspect the build video after the break.

Need a faster, easier way to take a closer look without breaking the bank? We hear those slim earwax-inspection cameras are pretty good.

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RC HalfTrack Is Lasercut Masterpiece

August 29, 2020 by Lewin Day 11 Comments

The half-track is a vehicle design that has gradually fallen out of favour in the decades since World War II. Combining the benefits of easy driving and handling of wheeled vehicles with the strong mud and snow performance of a tracked vehicle, they served a niche before largely being phased out with the rise of the armoured personnel carrier. [JackCarter] wished to build his own, so whipped up a lasercut RC version of the SdKfz 251 22.

The work is impressive, with [JackCarter] creating the design in Solidworks from photos and illustrations of the vehicle. The moving parts are lasercut, including the tracks themselves, assembled from many tiny lasercut MDF parts. The benefit of using lasercutting to make the model is that it was easy for [Jack Carter] to create simple jigs to ease the process of putting the tracks together. A NodeMCU with a motor shield controls the gear motors used to drive the tracks, and drives a servo for steering. Control is via a smartphone, thanks to the Blynk framework which makes building apps for custom projects easy.

The finished product really shows off [JackCarter]’s 3D design skills, and looks like great fun to build and drive. We’d love to see it with a lick of paint and some period decals to really complete the look. Hackers love a good tracked vehicle, and we’ve seen some impressive builds before. Video after the break.

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A Tiny Jacob’s Ladder You Can Build At Home

August 29, 2020 by Lewin Day 13 Comments

Big fizzing electrical arcs are fun, and handled properly, not too dangerous either. The Jacob’s Ladder is one such piece of arc-generating equipment, one that featured heavily in vintage sci-fi films. It remains a charming demonstration of high-voltage electrical principles, and you can easily build your own mini version at home.

The build starts with a basic high-voltage step-up kit that turns 4V DC into 15 kV at the output. At this voltage level, it’s possible to generate an arc in air. To create the Jacob’s ladder, the kit is wired up to a pair of closely-spaced electrodes that slowly get farther apart as they go up vertically. When an arc jumps from one electrode to the other, it ionises the air, and the voltage sags due to the current flow. The flowing current heats up the air, which begins to rise, taking the current path with it, causing the familiar climbing arc we all know and love. As the distance between the electrodes increases towards the top, the arc can eventually no longer be sustained. With no current flowing, the voltage rises again, and a new arc forms at the bottom of the device, repeating the process.

It’s a fun build that would make an excellent desk toy, albeit best shown under glass to avoid accidental electric shocks. You can even build a larger one out of microwave parts if you’re so inclined. Video after the break.

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This Geiger Counter Has Few Parts

August 26, 2020 by Al Williams 12 Comments

With all the focus on biological problems, we might forget that sometimes it’s handy to know about radiation hazards, too. [Ryan Harrington] shows us how to make a Geiger counter with very few parts, and you can see the results in the video below.

The glut of surplus Russian tubes has made this a common project, but we were amused to see the main part of the high-voltage supply was gutted from a cheap electronic flyswatter sourced from Harbor Freight. Even without a coupon, it only costs about $4.

There’s also a stack of zener diodes, a transistor, and some resistors. A battery, a piezo speaker, and a switch round out the bill of materials. Even then, the switch was upcycled from the flyswatter, so there’s not much to buy.

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E-Paper Display Shows Movies Very, Very Slowly

August 23, 2020 by Dan Maloney 12 Comments

How much would you enjoy a movie that took months to finish? We suppose it would very much depend on the film; the current batch of films from the Star Wars franchise are quite long enough as they are, thanks very much. But a film like Casablanca or 2001: A Space Odyssey might be a very different experience when played on this ultra-slow-motion e-paper movie player.

The idea of displaying a single frame of a movie up for hours rather than milliseconds has captivated [Tom Whitwell] since he saw [Bryan Boyer]’s take on the concept. The hardware [Tom] used is similar: a Raspberry Pi, an SD card hat with a 64 GB card for the movies, and a Waveshare e-paper display, all of which fits nicely in an IKEA picture frame.

[Tom]’s software is a bit different, though; a Python program uses FFmpeg to fetch and dither frames from a movie at a configurable rate, to customize the viewing experience a little more than the original. Showing one frame every two minutes and then skipping four frames, it has taken him more than two months to watch Psycho. He reports that the shower scene was over in a day and a half — almost as much time as it took to film — while the scene showing [Marion Crane] driving through the desert took weeks to finish. We always wondered why [Hitch] spent so much time on that scene.

With the proper films loaded, we can see this being an interesting way to really study the structure and flow of a good film. It’s also a good way to cut your teeth on e-paper displays, which we’ve seen pop up in everything from weather stations to Linux terminals.

Graphene Prints More Smoothly Under The Influence Of Alcohol

August 22, 2020 by Kristina Panos 10 Comments

If you’ve ever sloshed coffee out of your mug and watched the tiny particles scurry to the edges of the puddle, then you’ve witnessed a genuine mystery of fluid mechanics called the coffee ring effect. The same phenomenon happens with spilled wine, and with functional inks like graphene.

Graphene and other 2D crystals print much better under the influence of alcohol.

The coffee ring effect makes it difficult to print graphene and similar materials onto silicon wafers, plastics, and other hard surfaces because of this drying problem. There are already a few commercial options that can be used to combat the coffee ring effect, but they’re all polymers and surfactants that negatively affect the electronic properties of graphene.

Recently, a group of researchers discovered that alcohol is the ideal solution. In the case of spilled graphene, the particles fleeing for the edges are naturally spherical. By adding a mixture of isopropyl and 2-butanol alcohol, they get flattened into a pancake shape, resulting in smoother deformation during the drying process and an easier printing process with better results.

Graphene is quite interesting by nature, and has many uses. It can shift from an insulator to a superconductor with the right temperature changes, and it can desalinate sea water for drinking.

Print Your Way To Keyboard Stability

August 20, 2020 by Kristina Panos 2 Comments

Keyboard key stabilizers, or stabs as they’re known in enthusiast circles, do exactly what you’d expect — they stabilize longer keys like the Shifts and the space bar so that they don’t have to be struck dead-center to actuate evenly. Stabs work by flanking the key switch with two non-functional switch actuators linked with a thick wire bar. Some people love stabs and insist on stabilizing every key that’s bigger than 1u, while other people think stabs are more trouble than they’re worth for various reasons, like rattling.

[Riskable 3D Printing] has been working on a parametric, printable stabilizer system for Cherry MX caps that uses small disk magnets to keep the wire in place. As you can see in the video (embedded after the break), the result is a crisp clacker that doesn’t rattle. The magnets stabilize the wire, so it snaps back quite nicely.

Although the print is an easy one, [Riskable] says the design process wasn’t as cut and dried as it seems. The center points of the stabilizer stems aren’t supposed to be in the center of cutouts, even though it looks that way to the naked eye. After that, the pain point has shifted to the wire, and getting it as straight as possible before making the necessary bends. [Riskable] is going to make a straightener to help out, and we suggest something like this one.

Clacker hacking is quite the rabbit hole, especially when combined with 3D printing. We recently saw a completely 3D-printed macro pad, springs and all.

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