Pendulum clocks aren’t used quite as often these days as their cumbersome mechanics and timekeeping abilities have long been outshone by electronic alternatives. However, they’re still fun and they do work, so [PuzzLEGO] set about building a working example with Lego.
The rear view reveals the escapement built from Lego Technic parts.
The core of the clock is the escapement, a linkage which the pendulum can only turn in one direction. As the pendulum swings once per second, it lets the escapement gear turn one notch forward at a time, turning the gears of the clock which drive the hands. It’s powered with a falling weight in the form of a drink bottle full of water, which turns the gears of the clock via a chain.
The clock can only run for approximately an hour, so it’s set up with a second and minute hand instead of the more usual minute and hour hand. However, with the pendulum tuned to the appropriate length and the weight fitted, it pleasantly ticks and tocks the seconds away.
When it comes to mechanical timepieces, we’re used to seeing mechanisms stuffed with tiny gears and wheel, often of marvelous complexity and precision. What we’re perhaps less used to seeing is a clock that uses chains and sprockets, and that looks more like what you’d find on a bicycle on your typical bicycle.
We can’t recall seeing anything quite like [SPE]’s “Time Machine” before. It’s one of those builds that explains itself by watching it work, so check out the video below and you’ll see where this one is going. The clock has three loops of roller link chain, each of which has a series of numbers welded to the links. The loops of chain are advanced around sprockets by a trio of geared-down motors, with the numbers standing up straight at the top of each loop. A microcontroller keeps track of the time and starts the clock advancing every minute, but a series of microswitches that are activated by the passing chain do all the rest of the control — sounds like a perfect time to say, “Could have used a 555,” but we still think it’s great the way it is.
Surprisingly, [SPE]’s clock seems like it wouldn’t be that hard to live with. Many unique electromechanical clocks that we feature, like a clock that’s nothing but hands or The Time Twister, are a little on the noisy side. While “Time Machine” isn’t exactly silent, its whirring isn’t terrible, and even though its clicks are a little loud, they’ve got a satisfying mechanical sound to them.
Back in the old days, we didn’t have fancy digital clocks. No, we had good analog clocks with a big hand and a little hand, and if you wanted to know the time you had to look at the clock and figure out which number each hand was pointing at, or kind of pointing at. It wasn’t easy, and we liked it that way.
So now, along comes an analog clock that’s nothing but the hands — no dial, no numbers, just hands. How is such a thing possible? The clue is in the clock’s name: AKUROBATTO, and in the video below, which shows the acrobatic movements of the clock’s hands as it does its thing. Serial improbable-clock maker [ekaggrat singh kalsi] clearly put a lot of thought into this mechanism, which consists of the hands and a separate base. The hands are joined together at one end and powered by small stepper motors. The base has two docking areas, where servo-driven claws can grasp the hand assembly, either at the center pivot or at the tip of either hand. With a little bit of shuffling around at transition points, the hands sweep out the hours and minutes in a surprisingly readable way.
For as cool as the design of AKUROBATTO is, the internals are really something else. There are custom-built slip rings to send power to the motors and the Arduinos controlling them, sensors to determine the position of each hand, and custom gearboxes for the steppers. And the locking mechanisms on the base are worth studying too — getting that right couldn’t have been easy.
On [Jan Derogee]’s desk is something that wouldn’t look out of place for many of us, a pile of computer magazines with a case of 3.5″ floppy disks on top of it. The causal observer would see nothing more than the detritus of a retrocomputer enthusiast’s existence, but stick around. In fact it’s a clock, and one of the most unusual ones we’ve seen in a long time.
How can a box of floppies tell us the time? Selected disks have custom labels that look as though they might be authentic game collections, but in reality are fakes that carry numbers alongside the game art. An ingenious system of cams hidden in the hollowed out pile of magazines raises the correct floppies to tell the time, hours on the left row and minutes to the closest five minutes on the right. The floppies are modified by the removal of some plastic and the disk itself, because early versions had a habit of shredding disks. A final touch comes in the form of a Nokia phone on the desk next to the clock which plays a tune in lieu of chimes on the hour. You can see the clock in action in the video below the break.
We’ve all been online from home a bit more than usual lately, in ways that often stretch the limits of what our ISP can muster. You know the signs — audio that drops out, video sessions that make you look like [Max Headroom], and during the off-hours, getting owned in CS:GO by pretty much everyone. All the bandwidth in the world won’t make up for high latency, and knowing where you stand on that score is the point of this ping-tracking clock.
This eye-catching lag-o-meter is courtesy of [Charl], who started the build with a clock from IKEA. Stripped of pretty much everything but the bezel, he added a coaxial clock motor and a driver board, along with a custom-printed faceplate with logarithmic scale. The motors are driven by an ESP32, which uses internet control message protocol (ICMP) to ping a trusted server via WiFi, calculates the proper angles for the hands, and drives the motors to show you the bad news. There’s also an e-paper display in the face, showing current server and WiFi settings.
We really like how this clock looks, and if it wasn’t for the fact that the numbers it displays would often be too depressing to bear, we’d build one in a snap. If facing the painful truth isn’t your style, there are other neat ICMP tricks that you can try instead.
[Willem Koopman aka Secretbatcave] was looking at a master clock he has in his collection which was quite a noisy device, but wanted to use the matching solenoid slave clock mechanism he had to hand. Willem is a fan of old-school ‘sector’ clocks, so proceeded to build his ideal time piece — Vibrmatic — exactly the way he wanted. Now, since most time keeping devices utilise a crystal oscillator — which is little more than a lump of vibrating quartz — why not scale it up a bit and use the same principle, except with a metal tuning fork? (some profanity, just to warn you!)
Shock-mounted tuning force oscillator
A crystal oscillator operates in a simple manner; you put some electrical energy in, it resonates at its natural frequency, you sense that resonance, and feed it back into it to keep it sustaining. With a tuning fork oscillator, the vibration forcing and the feedback are both done via induction, coils act as the bridge between the electronic and mechanical worlds.
By mounting the tuning fork onto a shock mounting, the 257 Hz drone was kept from leaking out into the case and disturbing the household. This fork was specified to be 256 Hz, but [Willem] reckons the drag of the electromagnets pushed it off frequency a bit. Which make sense, since its a mechanical system, that has extra forces acting upon it.
The sector face was CNC cut from aluminium, the graphics engraved, then polished up a bit. Finally after a spot of paint, it looks pretty smart. Some nice chunks of upcycled wood taken from some building work spoils formed the exposed enclosure. On the electronics side, after totally ignoring the frequency error, and then tripping over a bunch of problems such as harmonics in the oscillation, and an incorrectly set-up divider, a solution which seemed to work was found, but like always, there are quite a few more details to the story to be found in the build log.
Cheap GPS units are readily available nowadays, which is great if you have something that needs to be very precisely located. Finding the position of things is one of many uses for GPS, though. There are plenty of ways to take advantage of some of the ancillary tools that the GPS uses to determine location. In this case it’s using the precise timekeeping abilities of the satellites to build a microsecond-accurate network time protocol (NTP) server.
GPS works by triangulating position between a receiver and a number of satellites, but since the satellites are constantly moving an incredibly precise timing signal is needed in order to accurately determine location from all of these variables. This build simply teases out that time information from the satellite network and ignores the location data. There are only two parts to this build, a cheap GPS receiver and a Raspberry Pi, but [Austin] goes into great detail about how to set up the software side as well including installing PPS, GPSd, and then setting up the actual NTP server on the Pi.
While this is an excellent way to self-host your own NTP server if you don’t have Internet access (or just want to do it yourself), [Austin] does note that this is probably overkill on timekeeping as far as accuracy goes. On the other hand, the Raspberry Pi has no built-in real time clock of its own, so this might actually be a cost-competitive way of timekeeping even when compared to something more traditional like a DS3231 RTC module.
