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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Eight Motors Can Sure Pump A Lot Of Water

Once upon a time, 3D printing was more of a curiosity than a powerful tool, with many printing trinkets and tchotchkes rather than anything of real use. However, over the years as technology and techniques have progressed, we now see more application-ready builds. This water pump from [Let’s Print] is a great example.

The pump consists of two major pieces – a drive unit, and an impeller. The drive unit consists of a gearbox that combines the power of eight electric motors, driving a single shaft. This is all achieved with striking yellow ABS gears in a black housing. The build video does a great job of explaining how to make the project work with different motors, and how to properly use the bolt adjuster to set the backlash on the gear train. The drive unit is then used to turn a 3D-printed impeller pump which is capable of delivering a great deal of water very quickly.

When fired up, the leaky assembly makes an awful racket and a huge mess, but sure as heck shifts a lot of water while it does so. Watching the water spray off the gears as it leaks through the bearings is a great sight, and it’s clear that the device works well. We’d love to see a cost and performance analysis of this pump versus a commercial offering.

While it’s certainly not the most rugged build, it’s a fun one that nevertheless gets the job done. We’d love to see this running a foam machine or a classic slip and slide. Video after the break.

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Plastic Prosthetics For Rubber Duckies

Will someone please think of the rubber duckies?!

For decades they’ve been reduced to a laughing stock: a caricature of waterfowl. Left without a leg to stand on, their only option is to float around in the tub. And they don’t even do that well, lacking the feet that Mother Nature gave them, they capsize when confronted with the slightest ripple. But no more!

Arise!

Due to the wonders of 3D printing, and painstaking design work by [Jan] from the Rubber Ducky Research Center, now you can print your own rubber ducky feet. We have the technology! Your ducks are no longer constrained to a life in the tub, but can roam free as nature intended. The video (embedded below) will certainly tug at your heartstrings.

OK, it’s a quick print and it made my son laugh.

The base and legs probably don’t fit your duck as-is, but it’s a simple matter to scale them up or down while slicing. (Picture me with calipers on the underside of a rubber ducky.) The legs were a tight press-fit into the body, so you might consider slimming them down a tiny bit when doing the scaling, but this probably depends on your printer tolerances.

It looks snazzy in gold-fleck PETG, and would probably work equally well for some more elaborate rubber duckies as well.

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DIY Baby MIT Cheetah Robot

3D printers have become a staple in most makerspaces these days, enabling hackers to rapidly produce simple mechanical prototypes without the need for a dedicated machine shop. We’ve seen many creative 3D designs here on Hackaday and [jegatheesan.soundarapandian’s] Baby MIT Cheetah Robot is no exception. You’ve undoubtedly seen MIT’s cheetah robot. Well, [jegatheesan’s] hack takes a personal spin on the cheetah robot and his results are pretty cool.

The body of the robot is 3D printed making it easy to customize the design and replace broken parts as you go. The legs are designed in a five-bar linkage with two servo motors controlling each of the four legs. An additional servo motor is used to rotate an HC-SR04, a popular ultrasonic distance sensor, used in the autonomous mode’s obstacle avoidance mechanism. The robot can also be controlled over Bluetooth using an app [jegatheesan] developed in MIT App Inventor.

Overall, the mechanics could use a bit of work — [jegatheesan’s] baby cheetah probably won’t outpace MIT’s robot any time soon — but it’s a cool hack and we’re looking forward to a version 3. Maybe the cheetah would make a cool companion bot?

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IWings For The New Apple Power Adaptor

You might remember the old Apple MagSafe adaptor with the cute little fold out “wings” that served not only as a pragmatic cable management tool, but in our experience also expedited the inevitable and frayed end of your charger. Apple seems to have remedied the latter by opting for removable USB-C cables in latest designs, but the complete omission of a pop-out cable spooling contraption is problematic.

[Eric], an industrial designer, took it upon himself to design a 3D printed add on for the new generation of chargers. His video is certainty one of those satisfying accounts, where the whole process from conceptional sketch to a working Hack is neatly self-contained in a single video.  The design is largely based off the original version, implemented in PLA together with piano wire serving as the hinge pin. We think this is a very good example of how 3D printers can be used to personalise and tweak commercial products to suite particular needs.

If you are looking for a more general 3D printed cable management tool, check out this geared cable winder we featured earlier.

Modular Mouse Packs Features

Not only do console gamers complain about the use of a mouse, but PC users themselves often don’t have kind words to say even about some of the higher-end options. Granted, their gripes aren’t about game experience or balance, they’re usually about comfort, features, or longevity of the mice themselves. So far we haven’t seen many people try to solve these problems, but [benw] recently stepped on the scene with a modular mouse that can fit virtually any need.

Called the RX-Modulus, this mouse has been designed from the ground up to be completely open source from hardware to software. Most of the components can be 3D printed to suit an individual’s particular grip style by making adjustments. The electronics can be custom fitted as well. Users can swap out mouse buttons and wheels in any number of positions, and replace them when they wear out. To that end, one of the goals of this project is also to avoid any planned obsolescence that typically goes along with any current consumer-level product.

While [benw] currently only has a few prototypes under his belt, he’s far enough along with the project that he’s willing to show it off to the community. His hopes are that there are others that see a need for this type of mouse and can contribute to the final design. After all, there are all kinds of other custom mice out there that would have been much easier builds with [benw]’s designs at hand.

Hands-Free Oreo Dispenser, Now With Milk

A while back, [Emiel] aka [The Practical Engineer] created a hands-free Oreo dispenser for his shop. This was a necessary addition to his fleet of handy tools, and allowed him to multitask much more effectively by using a sander, for example, at the same time that he needed to eat a cookie. Of course, this time-saving device was missing one crucial element: milk. [Emiel] is back in this video to show off his milk-dispensing upgrade to his original Oreo dispenser.

A few ideas were considered before [Emiel] decided to build a separate unit for the milk dispenser, so as not to create a gigantic mess any time an Oreo was delivered, and also to maintain some decorum in the shop. He rebuilt the Oreo dispenser with a 3D printer and then also 3D printed the milk dispenser. The chin-activated switch inside the device turns on a small pump which squirts milk into the user’s mouth, presumably after an Oreo has been delivered.

There are a few problems with the build, but most are easily solved by replacing non-food-grade parts with plastic that is more safe for being around consumables. The only other thing we can see here is that it might be a little hard to keep things clean, both inside and out, but most Oreo-related builds like this one have at least some problem with cleanliness that isn’t impossible to keep up with.

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