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.

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Tiny Chain-Link Fence Made With Hand-Cranked Brilliance

Chain link fences are woven with a mechanism that is almost hypnotic to watch, so [Levsha] decided to build his own tiny hand-crank tabletop version to make tiny copper wire fences.

Chain link consist of a series of wires bent and woven in a zigzag pattern. The zigzag bends are made by winding the wire around a rotating flat plate inside a stationary tube with a spiral slot in the side to keep the spacing of the bends consistent. [Levsha]’s version is roughly 1/10 scale of the real thing, and only does the bending and winding parts. Linking the bent wire together is up to the operator. All the components were machined on a lathe and CNC router, and beautifully finished and assembled on a wood base. The hardest part was the tube with the spiral slot, which took a few attempts to get right. [Levsha] initially tried to use steel wire, but it was too stiff and caused the winding mechanism to lock up. 0.4 mm copper wire turned out to be the best choice.

Although there is no practical use for this device that we can see, the craftsmanship is excellent, and it is one of those videos that reminds us how badly we want some machine tools.

Fine attention to detail is really what makes videos like this enjoyable to watch. Wee seen a few other such project, like a beautiful scratch-built lathe, or a pneumatic powered drone that can’t fly.

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