Chain Link Clock Drags Time Along

When it comes to building quirky clocks that also double up as beautiful animated sculptures, [Ekaggrat Singh Kalsi] is a master par excellence. His latest offering is the Getula, a time piece inspired by an old, discarded bicycle chain, while the name seems inspired by the chain kingsnake — Lampropeltis getula – due to its snake like movements. Getula shows time by manipulating eight short pieces of chain to show four digits representing hours and minutes. But wrangling a flexible piece of chain to morph in to numerals turned out to be a far more complex endeavour than he bargained for, and he had to settle for a few compromises along the way.

He could not use real bicycle chains because they are too flexible and heavy, which made it impossible for them to hold the shapes he desired. Instead, he designed custom 3D printed chains similar to drag link chains used for cable management. For rigidity, he added O-rings in the chain joints to increase friction. But even this was not sufficient to completely form each digit using a single piece of chain.

The compromise was to use two pieces of chain per digit, which results in a more artistic expression of time keeping. Each piece of chain is pushed or pulled using stepper motors, and bent in to shape using servos. The end result is a mesmerising dance of chain links, steppers and servos every minute, around the clock.

Designing the clock was no trivial exercise, so [Ekaggrat] improved it over a couple of iterations. There are four modular blocks working in synchronism — each consisting of an Arduino Nano, two stepper motor drives with motors and two servos. Each chain has an embedded magnet at its start, which is sensed by a hall sensor to initialise the chain to a known position. A DS1307 RTC module provides timekeeping. The project is still work in progress, and [Ekaggrat] has managed to finish off just one module out of four — giving us a tantalizing glimpse of Getula welcoming 2021.

If you’d prefer something more shiny, check out his Unique Clock that finally unites Hackers and Sequins, while some of his other creations, such as the Edgytokei Clock and the Torlo Clock feature beautiful and intricate 3D printed mechanisms.

Continue reading “Chain Link Clock Drags Time Along”

The Black Magic Of A Disappearing Linear Actuator

Many of the projects we serve up on Hackaday are freshly minted, hot off the press endeavors. But sometimes, just sometimes, we stumble across ideas from the past that are simply too neat to be passed over. This is one of those times — and the contraption in question is the “Kataka”, invented by [Jens Sorensen] and publicised on the cover of the Eureka magazine around 2003.

The device, trademarked as the Kataka but generically referred to as a Segmented Spindle, is a compact form of linear actuator that uses a novel belt arrangement to create a device that can reduce to a very small thickness, while crowing to seemingly impossible dimensions when fully extended. This is the key advantage over conventional actuators, which usually retract into a housing of at least the length of the piston.

It’s somewhat magical to watch the device in action, seeing the piston appear “out of nowhere”. Kataka’s youtube channel is now sadly inactive, but contains many videos of the device used in various scenarios, such as lifting chairs and cupboards. We’re impressed with the amount of load the device can support. When used in scissor lifts, it also offers the unique advantage of a flat force/torque curve.

Most records of the device online are roughly a decade old. Though numerous prototypes were made, and a patent was issued, it seems the mechanism never took off or saw mainstream use. We wonder if, with more recognition and the advent of 3D printing, we might see the design crop up in the odd maker project.

That’s right, 3D printed linear actuators aren’t as bad as you might imagine. They’re easy to make, with numerous designs available, and can carry more load than you might think. That said, if you’re building, say, your own flight simulator, you might have to cook up something more hefty.

Many thanks to [Keith] for the tip, we loved reading about this one!

Continue reading “The Black Magic Of A Disappearing Linear Actuator”

Making Your Own Chain Sprockets, The Tidy Way

Chain sprockets are a key drivetrain component in a lot of builds. Unfortunately they can be difficult to source, particularly for those outside the reach of retailers like McMaster-Carr. In such situations, you might consider making your own.

The toothed profile on a chain sprocket can be produced in a simple manner by drawing a base circle, along with a series of circles spaced appropriately for the chain in question. This involves measuring the pitch and roller diameter of the chain. With these measurements in hand, a template can be created to produce the sprocket.

From there a series of holes are drilled to rough out the basic shape of the teeth, before the sprocket is then cut down to its appropriate outer diameter. The finishing work consists of chamfering the sprocket’s thickness, as well as the filing the sharp edges of the teeth for smooth engagement.

It’s a quick and easy method for producing sprockets with well-defined, accurate profiles. We’ve featured other rough and ready methods before, too. Video after the break.

Continue reading “Making Your Own Chain Sprockets, The Tidy Way”

DIY CNC Router Uses Chains The Right Way

There are a million and one ways to build your own CNC router, depending on your tastes, budget, and application, your design choices will differ accordingly. [Steve Tyng] was well aware of this when undertaking his project, and built the machine that made sense for him.

[Steve’s] build has a strong focus on keeping costs down, and that’s reflected in the hardware used. Wanting a large work area of 30″ x 60″, off-the-shelf linear rails in 6 foot lengths were prohibitively expensive. Instead, 1″ angle iron was sourced from the local garden centre, and used in conjunction with steel v-bearings. It’s a lot cheaper, and good enough for the application at hand, so why not? Other smart choices abound, such as using an IKEA cabinet as the base, and a fanless computer to run the show to avoid death by dust.

When it came time to build the axes, there was plenty of roller chain on hand. Chain is usually passed up for options such as timing belts or ballscrews in the CNC community, as it tends to stretch over time and offers poor accuracy. However, [Steve] took stock of the drawbacks of the method, and made efforts to overcome these weak points in the design. The Y and X axes were specially designed to keep the chain supported along its length. This helped avoid the problem of long drooping chains and poor tension.

While it’s not an industrial-strength build with world-beating accuracy, it’s a solid CNC machine that can carve out large workpieces without issue. Over the years, we’ve seen plenty of DIY CNCs, built with everything from PVC pipe to welded steel. Video after the break.

Continue reading “DIY CNC Router Uses Chains The Right Way”

Old Chainsaw Repurposed For Kitchen Use

There are many ways to keep critical appliances running during a power outage. Maybe a UPS for a computer, a set of solar panels to charge your phone, or even a generator to keep your refrigerator or air conditioning working. This modification to a standard blender will also let you ride through a power outage while still being able to make delicious beverages. It runs on gasoline.

The build uses an old chainsaw to power the blades of the blender. [Bob] was able to design and build an entirely new drivetrain to get this device to work, starting by removing the chainsaw chain and bar and attaching a sprocket to the main shaft of the motor. A chain connects it to a custom-made bracket holding part of an angle grinder, which supports the blender jar. Add in a chain guard for safety and you’ll have a blender with slightly more power than the average kitchen appliance.

The video of the build is worth watching, even if your boring, electric-powered blender suits your needs already. The shop that [Bob] works in has about every tool we could dream of, including welders, 3D printers, band saws, and even a CNC plasma cutter. It reminds us of [This Old Tony]’s shop.

Continue reading “Old Chainsaw Repurposed For Kitchen Use”

Retrotechtacular: Making Chains

We take the everyday materials of engineering for granted, as ubiquitous components rather than as complex items in their own right. Sure, we know that an integrated circuit represents the pinnacle of a hundred years’ development in the field of electronics, but to us it’s simply a black box with some wires. Even with more basic materials it’s easy to forget the work that goes into their manufacture, as for example with the two videos below the break. They both take a look from a very different angle at the creation of the same product: metal chain. However, the approaches couldn’t be more different as the two examples are separated by about a century and with vastly different techniques and material.

The first film follows the manufacture of the chain and anchor that would have been found on a ship around the turn of the twentieth century. One of the text frames mentions Netherton Works, allowing us to identify it as being filmed at N. Hingley & Sons, a specialist anchor and chain manufacturer based in the area to the west of the English city of Birmingham known as the Black Country. It’s a window on a manufacturing world that has entirely disappeared, as large gangs of men do almost every task in the process by hand, with very few automated steps. There is scant regard for health and safety in handling the huge pieces of red-hot metal, and the material in question is not the steel we’d be used to today but wrought iron. The skill required to perform some of the steps such as forge-welding large anchor parts under a steam hammer is very significant, and the film alone can not convey it. More recent videos of similar scenes in Chinese factories do a better job.

The other video is contemporary, a How It’s Made look at chain manufacture. Here the chains involved are much smaller, everything is done by automated machinery, and once we have got over marveling at the intricacy of the process we can see that there is far more emphasis on the metallurgy. The wire is hard drawn before the chain is formed, and then hardened and annealed in a continuous process by a pair of induction heaters and water baths. I’m trying really hard to avoid a minor rant about the propensity of mass-market entertainment such as this for glossing over parts of the process. A keen eye notices that each link has become welded but we are not shown the machine that performs the task.

Most of us will never have the chance of a peek into a chain factory, so the medium of YouTube industrial films and videos is compulsive viewing. These two views of what is essentially the same process could not be more different, however it would be wrong to assume that one has replaced the other. There would have been mechanised production of small chains when the first film was made, and large chains will still be made today with fewer workers and from arc-welded steel rather than wrought iron. Plants like the Hingley one in Netherton may have closed in the 1980s, but there is still a demand for chains and anchors.

Continue reading “Retrotechtacular: Making Chains”

Steampunk-Inspired Art Clock!

Getting paid to do what you enjoy is a special treat. A machinist and fabricator by trade — hobbyist hacker by design — [spdltd] was commissioned to build a mechanical art installation with a steampunk twist. Having complete creative control, he convinced his client to let him make something useful: a giant electro-mechanical clock.

Pieced together from copper, brass, steel, aluminium, and stainless steel, this outlandish design uses an Arduino Yun — a combination Linux and Arduino microcontroller board — to control the stepper motor and query the internet for the local time. Upon boot, the clock auto-calibrates by rotating the clock face until a sensor detects an extra peg and uses that to zero on twelve o’clock; the Yun then grabs the local time over the WiFi and sends the stepper motor a-spinning ’till the correct time is displayed.

At first glance, you may find it hard to get an accurate read of what time it is, but an accent piece’s pegs denote the quarter hour once it lines up with the notch above each hour. At least this one doesn’t require you to match colours or do much math to check the time.

Continue reading “Steampunk-Inspired Art Clock!”