This Mechanical 7-Segment Clock Tells Time with Servos

When it comes to digital clocks, they typically use segmented or dot-matrix displays in order to tell the time. But one thing most of these displays have in common is that have no moving parts. Not so with this unusual timepiece, which looks like a digital display, but is actually mechanical.

Michael Klements of The DIY Life built this cool clock that uses 28 micro-servo motors to move its segments into place.

The brains of the operation are an Arduino Uno controller and a DS1302 clock module to keep time. As the minutes tick away, the circuit and code instruct the servos to rotate back and forth. In the back position, it hides the segment on its side, while in the forward position, the segment is visible. By 3D printing the segments with a brightly-colored translucent green filament, they look kind of like they’re illuminated. You can see the clock in action in the video below:

If you’d like to build your own mechanical 7-segment clock, you can check out all of the details over on Instructables or on The DIY Life. You’ll need some basic electronics skills, along with access to a 3D printer.

UK “Cops” Use Dalek to Scare People into Isolating

When it comes to scary monsters from science fiction, Doctor Who’s Daleks rank high on the list. These soulless robotic aliens go around the universe, exterminating all those who stand in their way. So what better way to get people to stay inside of their homes during the COVID-19 pandemic, then to bring a Dalek to their doorsteps?

Somewhere in the UK, somebody programmed a Dalek to drive around a neighborhood and proclaim “ALL HUMANS MUST KEEP INDOORS. ALL HUMANS WILL SELF ISOLATE. BY ORDER OF THE DALEKS.” If that doesn’t get you to shelter in place, nothing will. Except maybe some weeping angels hanging outside your front door.

While I was hoping this was done by an actual police department, the stunt actually appeared on the Sandford Police twitter feed. And if you don’t know who the Sandford Police are, you need to stop what you’re doing, and go stream Hot Fuzz right now.

[via Reddit]

Twisting Steel with LEGO Motors

LEGO bricks are some of the most awesome things on earth. They’re incredibly versatile for building all kinds of structures, and you can make some pretty impressive machines with them when you combine them with Technic and Mindstorms parts. I’ve always assumed that LEGO motors and gears aren’t particularly strong, but it turns out with the proper engineering, you can use them to bend and twist steel.

Brick Experiment Channel loves to create LEGO machines that show off their strength. He recently built a rig that uses a pair of LEGO Power Functions XL motors along with a number of gears to reduce their speed and increase their torque output. The result is a machine that that outputs 15 Newton meters (~11 lb-ft.) of torque, and is capable of taking a stainless steel axle and twisting it like a drill bit (or a Twizzler).

The builder’s ultimate goal was to see if he could actually break the steel rod before the LEGO parts would fail. By twisting the metal back and forth numerous times, he was ultimately able to introduce enough metal fatigue to to make the axle crack. It’s pretty amazing that this is possible, and looks like a fun science experiment for LEGO fans to try and replicate at home.

This Machine Will Probably Never Finish a Full Rotation

When it comes to telling time with an analog clock, the idea of gear reduction is a very critical piece of the puzzle. Basically, a set of multiple gears work in concert to gradually rotate at slower speeds. So a single motor can drive the seconds, minutes, and hour hands on a dial.

But rather than just reducing the speed of a gear a couple of times, engineer Daniel de Bruin decided to make what he says is the “biggest reduction gear in the universe.” Well, it may not be the largest in dimension, but it’s definitely the most complicated, with 100 gears, each gradually reducing the speed from the gear before it.

Each successive gear turns at exactly 1/10th of the speed of its predecessor. The result is a setup that would take literally eons before it would rotate its final gear.

According to the guys at Gizmodo, you’d have to turn the first gear

10,000,000,000,000,000,000,000,000,000,000,000,
000,000,000,000,000,000,000,000,000,000,000,000,
000,000,000,000,000,000,000,000,000,000

times to move the last gear to move just one position. Man, that’s a whole lot of zeros, and I definitely can’t count that high.

The machine’s creator explains the rationale behind his build: “Today at 14:52 I will be exactly 1 billion seconds old. To celebrate I build this machine that visualizes the number googol. That’s a 1 with a hundred zeros. A number that’s bigger than the atoms in the known universe. This machine has a gear reduction of 1 to 10 a hundred times. In order to get the last gear to turn once you’ll need to spin the first one a googol amount around. Or better said you’ll need more energy than the entire universe has to do that.”

If you’ve got a full hour to kill you can watch the contraption get through the first few of layers of gears…

[via Gizmodo]

Tumblr’s digital literacy campaign targets fake news and bullying

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Making Music with Microsoft Excel

Microsoft Excel has long been one of the most popular pieces of business software, and is used by pretty much every company on the planet to create spreadsheets, databases, charts, tables, and financial models. It also can be used to play video games. Now, it turns out it can make music as well.

Using custom Visual Basic macros and buttons, musician Dylan Tallchief was able to create a working drum machine sequencer that works right Excel. The trick is that it generates MIDI signals and sends them to either a virtual synthesizer on your computer, or to an external MIDI device. Check it out in action in the video below:

If you’ve got Excel 2019 or Office 365 and want to give this thing a whirl, you can download the Excel Drum Machine spreadsheet on Google Drive, and if you enjoy what you heard, consider supporting Dylan on Patreon.

The Baby Head Theremin Is the Stuff of Nightmares

Are you sleeping too well? Well, let’s change that right now. The only thing creepier than the decapitated bald head of a doll is one with light-up red eyeballs, and that makes all kinds of haunting sounds when you get near it.

What you’re looking at – and about to listen to – is a custom built photo-theremin that emits those weird and wild sci-fi noises when you place your hand above its head.

The Worst Things for Sale points out that you can actually buy one of these things over on Amazon if you really want to. The XLPC Photo Theremin is available with a baby doll head, an alien head, a skull head, or in a slightly less creepy standalone version.

[via Neatorama]