Day: November 12, 2020

Domino Clock Tells The Time In Style

November 12, 2020 by 11 Comments

It seems there are as many ways to display the time as there are ways to measure it in the first place. [Kothe] saw a fancy designer domino clock, and wanted a piece of the action without the high price tag. Thus, the natural solution was to go the DIY route.

An Arduino Nano is the heart of the build, paired with a DS1307 RTC for accurate timekeeping. The case of the clock consists of a 3D printed housing, fitted with layers of lasercut acrylic. Behind this, a smattering of WS2812B addressable LEDs are fitted, which shine through the translucent grey plastic of the front panel. This enables each LED to light up a dot of the domino, while remaining hidden when switched off. Reading the time is as simple as counting the dots on the dominoes. The first domino represents hours, from 1 to 12, while the second and third dominoes represent the minutes.

As a timepiece, the domino clock serves well as a stylish decor piece, and could also be a fun way to teach kids about electronics and telling the time. Makers do love a good timepiece, and our clock tag is always overflowing with fresh hacks on a regular basis. If you’ve got your own fancy build coming together at home, you know who to call!

Rotating Magnetic Fields, Explained

November 12, 2020 by 11 Comments

If you made a motor out of a magnet, a wire coil, and some needles, you probably remember that motors and generators depend on a rotating magnetic field. Once you know how it works, the concept is pretty simple, but did you ever wonder who worked it all out to start with? Tesla figures into it, unsurprisingly. But what about Michael Dobrowolsky or Walter Bailey? Not common names to most people. [Learn Engineering] has a slick video covering the history and theory of rotating magnetic field machines, and you can watch it below.

Motors operated on direct current were not very practical at the time and caused a jerky motion. However, Tesla and another inventor named Ferraris realized that AC current could cause a rotating magnetic field without a moving commutator.

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Bringing An IBM Model F Into 2020

November 12, 2020 by 41 Comments

We know that the Hackaday family includes many enthusiasts for quality keyboards, and thus mention of the fabled ‘boards of yore such as the IBM Model F is sure to set a few pulses racing. Few of us are as lucky as [Brennon], who received the familial IBM PC-XT complete with its sought-after keyboard.

This Model F has a manufacture date in March 1983, and as a testament to its sturdy design was still in one piece with working electronics. It was however in an extremely grimy condition that necessitated a teardown and deep clean. Thus we are lucky enough to get a peek inside, and see just how much heavy engineering went into the construction of an IBM keyboard before the days of the feather-light membrane devices that so many of us use today. There follows a tale of deep cleaning, with a Dremel and brush, and then a liberal application of Goo Gone. The keycaps had a long bath in soapy water to remove the grime, and we’re advised to more thoroughly dry them should we ever try this as some remaining water deep inside them caused corrosion on some of the springs.

The PC-XT interface is now so ancient as to have very little readily available in the way of adapters, so at first a PS/2 adapter was used along with a USB to PS/2 converter. Finally though a dedicated PC-XT to USB converter was procured, allowing easy typing on a modern computer.

This isn’t our first look at the Model F, but if you can’t afford a mechanical keyboard don’t worry. Simply download a piece of software that emulates the sound of one.

Highly Sensitive Camera Makes A Great Night Vision Scope

November 12, 2020 by 18 Comments

Traditional military-grade nightvision gear has a history stretching back to the Second World War, relying on photomultiplier tubes to help soldiers see in the dark. Such devices have trickled down to the civilian market in intervening years, however other simpler techniques can work too. [Happy_Mad_Scientist] whipped up a simple nightvision monocular using a very sensitive camera instead.

Due to the high noise, still photos don’t do it justice. The video quality is highly impressive for a system running with no IR illumination.

The camera in question is the Runcam Night Eagle 2, prized for its 0.00001 lux sensitivity. Black and white only, its capable of providing vision in moonlight and starlight conditions without external illumination. In this project, it’s hooked up to a monocle display designed for use with drone FPV setups. With lithium batteries and a charge circuit hooked up, and everything stuffed inside a compact 3D printed case, the final result is a portable, pocket sized night vision device for under $200 USD.

[Happy_Mad_Scientist] notes that in starlight conditions, it provides an advantage over other nighttime Airsoft players relying on IR illumination to see in the dark. We can imagine it would perform well in concert with a bright IR headlamp for those times when there’s simply no ambient light available – particularly indoors.

If your tastes are more military-spec, consider this teardown of a high-end Norweigan device. Video after the break.

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Three-Wheeled Turret Car Looks Like It Should Be Orbiting Thunderdome

November 12, 2020 by 31 Comments

In a post-apocalyptic world, this is the hacker you want rebuilding society. He’s showing off a three-wheeled go-kart that pivots the cockpit as it steers. A hand crank mounted at the center of the vehicle pivots each of the three wheels in place, but keeps the driver facing forwards with a matching rotation. Hit up the video after the break to see it for yourself.

The real question here is, how did he pull this off? The watermark on the video shows that this was published by [wo583582429], a user on Douyin (the platform known as TikTok in the US). We plied our internet-fu but were unable to track down the user for more of the juicy details we crave. If you have a lead on more info, leave it in the comments below. For now, please join us in speculating on this build.

This is a pretty good closeup of one of the wheel assemblies. First question is how does the turning mechanism work? Since all three wheels and hub are smoothly coordinated it’s likely this is a planetary gearing setup where the inner ring has teeth that turn the rings around the tires themselves. However, we can see a spring suspension system which makes us doubt the lower ring surrounding the tire would stay engaged with a planetary gear. What do you think?

Trying to figure out how control and locomotion happens is even more of a head-scratcher. First guess is that it’s electric from the mere simplicity of the setup and this closeup shows what looks like a circuit breaker and wires connecting to batteries on either side of the suspension system. But where is the electric motor?

It’s a horrible image, but this is the best we can do for a view of the other side of the wheel assembly. There is a box that appears to be made from aluminum mounted to the wheel frame. After a few hundred times through the demo video we don’t think there’s a chain drive going down to the axle. It doesn’t look like there is a hub motor at play here either. We wondered if there was a second smaller wheel under the top of the frame to drive the main tire, but again, the suspension system would make this unfeasible and at points in the video there is clear daylight. Spend some time reviewing the Zapruder demo film below and when you figure all of this out, clue the rest of us in please!

It’s awesome seeing bootstrapped vehicles come to life. One of our favorites remains this all-terrain motorcycle that has no problem taking on stairs.

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Tech Hidden In Plain Sight: Gas Pumps

November 12, 2020 by 67 Comments

Ask someone who isn’t technically inclined how a TV signal works or how a cell phone works, or even how a two-way switch in a hall light works and you are likely to get either a blank stare or a wildly improbable explanation. But there are some things so commonplace that even the most tech-savvy of us don’t bother thinking about. One of these things is the lowly gas pump.

Gas pumps are everywhere and it’s a safe bet to assume everyone reading this has used one at some point, most of use on a regular basis. But what’s really going on there?

Most of it is pretty easy to figure out. As the name implies, there must be a pump. There’s some way to tell how much is pumping and how much it costs and, today, some way to take the payment. But what about the automatic shut off? It isn’t done with some fancy electronics, that mechanism dates back decades. Plus, we’re talking about highly combustible materials, there has to be more to it then just a big tank of gas and a pump. Safety is paramount and, experientially, we don’t hear about gas stations blowing up two or three times a day, so there must be some pretty stout safety features. Let’s pay homage to those silent safety features and explore the tricks of the gasoline trade.

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Meticulous Bionic Hand

November 12, 2020 by 12 Comments

[Will Cogley] is slowly but surely crafting a beautiful bionic hand. (Video, embedded below.) The sheer amount of engineering and thought that went into the design is incredible. Those who take their hands for granted often don’t consider the different ways that their digits can move. There is lateral movement, rotation, flexion, and extension. Generally, [Will] tries to design mechanisms with parts that can be 3D printed or sourced easily. This constrains the hand to things like servos, cable actuation, or direct drive.

However, the thumb has a particularly tricky range of motion. So for the thumb [Will] designed to use a worm geared approach to produce the flexing and extension motion of the thumb. These gears need to be machined in order to stand up to the load. A small side 3d printed gear that connects to the main worm gear is connected to a potentiometer to form the feedback loop. Since it isn’t bearing any load, it can be 3d printed. While there are hundreds of little tiny problems still left to fix, the big problems left are wire management, finalizing the IP (Interphalangeal) joints, and attaching the whole assembly to the forearm.

All the step files, significants amounts of research, and definitions are all on [Will’s] GitHub. If you’re looking into creating any sort of hand prosthetic, the research and attention [Will] has put into this is work incorporating into your project. We’ve seen bionic hands before as well as aluminum finger replacements, but this is a whole hand with fantastic range and fidelity.

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