An electromechanical clock based on sliding frames

Watch Time Slide By With This Electromechanical Clock

February 27, 2023 by Robin Kearey 13 Comments

Back in the 18th century, clockmakers were held in high esteem, as turning pieces of metal and wire into working timepieces must have seemed like magic at the time. The advent of mass production made their profession largely obsolete, but today there are several hardware hackers whom you could consider modern heirs of the craft. [Hans Andersson] is one of them, and has made a name for himself with an impressive portfolio of electromechanical clocks. His latest work, called the Time Slider, is every bit as captivating as his previous work.

The mechanical display is almost entirely made of 3D printed components. Four flat pieces of red PLA form a basic 88:88 indicator, onto which the correct time is displayed by sliding frames that black out certain pixels. Those frames are moved up and down by a rack-and-pinion system driven by stepper motors. Evertyhing is controlled by an Arduino Mega, acoompanied by a DS3231 RTC and eight ULN2003-based stepper motor drivers.

[Hans] wrote a detailed assembly guide to go along with the STL files and Arduino code, so it should be easy make your own Time Slider if you have a decent supply of PLA filament. The display takes about ten seconds to update, but the process has certain hypnotic quality to it, helped by the mechanical whirring of the stepper motors in the background. Especially the hourly change of three or four digits at once is mesmerizing, as you can see in the video embedded below.

Time Slider is the latest in [Hans]’s long line of mechanical clocks, which includes the Time Twister series that evolved from a clever Lego-based design to a neat 3D-printed model. The rack-and-pinion system can also be used to make a compact linear clock.

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Can You Read Me The Time?

September 21, 2019 by Sharon Lin 11 Comments

If you’re like the average clock user, you’ve probably gotten annoyed at reading analog clocks before. Typically, the solution is just to use a digital timepiece, but [sjm4306] has opted to make a small word clock that you can carry with you wherever you go to remind you of the time in the English language.

Unlike a similar project made by [Gordan Williams], which uses an 8 x 8 LED matrix with an inkjet printed overlay, this small word clock uses a 3D-printed light box to achieve its letter matrix. In fact, they were inspired by all of the existing DIY word clock designs using anything from off-the-shelf LED arrays, transparency masks and WS2812s.

The design uses a home-brewed PCB design that runs off 5 V via USB. The design places the letters on the top stop and restricts layers to keep the solder mask and copper from obstructing the light. The bottom side uses the same design principle with a square shape that overlaps the letter. In order to block light between adjacent letters, the 3D-printed light box comes into play.

One design challenge for the letter matrix was fitting all possible minutes into the array. Rather than making a larger array of letters, [sjm4306] had the clock describe the time down to five-minute intervals then add asterisks for the full time. It’s a pretty understandable solution for keeping the design simple, and the letters all fit onto the design so well!

Using a pin map assigned to the I/O for the rows and columns of the array, the software toggles the states of the pins as a switch statement. For scanning the matrix, the software uses an interrupt that draws the current column of LEDs and updates the display image before incrementing to the next column. By skipping or not skipping cycles, this allows the display to look brighter or dimmer.

The time tracking is fairly simple, using a DS1302 serial real time clock chip – it even charges a super capacitor to keep time after power is removed!

To tackle the light scattered internally in the PCB’s FR4 material, a separator is used to contain the light. As a low-cost solution, while there is still some amount of light diffused, it’s definitely better than without the separator.

Almost all of the files used for building the small word clock are available on [sjm4306]’s project page, including the software and design files. It hopefully won’t be too long before we start seeing more of these low-cost word clock designs!

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Odd Clock Moves Minute Hand To Hour Hand

May 26, 2015 by Rich Bremer 31 Comments

We see a lot of clocks here on Hackaday. Some make it easy to tell the time, others are more cryptic. [dragonator] has done something that is so simple, we are surprised it isn’t more common. In a typical mechanical hand clock the minute and hour hands rotate around the same axis. [dragonator] decided to take the minute hand and move it out to the tip of the hour hand.

It works because of a gear system hidden behind the thick hour hand. As the hour hand turns, the gear system rotates, the last gear of which is connected to the minute hand. Since the minute hand rotates 12 times for every one revolution of the hour hand, the gear ratio can easily be calculated.

The 3D printed parts were designed by [dragonator] himself. All of the design files are available here for anyone who wants to build one of these neat clocks.

The clock uses a Trinket microcontroller board to keep track of the time and to send step signals to a StepStick that drives a NEMA 17 stepper motor. There is no on-board battery power for this clock, 9-12vdc comes in via a wall wart and is stepped down to 5v by the micro controller’s regulator. Even still, this is a great project that makes it fun to watch time pass, check the video out after the break.

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MRRF: (not Quite) Chocolate Clock

March 21, 2015 by Kristina Panos 25 Comments

[Jason] is a woodworker. At least, he was until he saw his first 3D printer. While he may still work in wood, he particularly likes adapting scroll saw patterns for 3D printing. His clock started as a woodworking pattern for use on a scroll saw. To adapt it for 3D printing, [Jason] scanned the plotter-sized pattern pieces into Inkscape, where he was able to do things like add bevels before sending the pieces to OpenSCAD.

As you might imagine, a great deal of work went into this build, beginning with the scanning. [Jason] starting scanning last October and finished in January. Printing started January 9th, and he told me the final pieces were printed early this morning. We know you want all the details, so here goes: this build took just over six rolls of PLA at 20% infill. It’s 48″ tall and about 24″ wide. It was printed on what [Jason] referred to as his “very modified” Replicator 2. He glued the pieces together with Testor’s, and that took about 30 hours. All through the project, he kept meticulous notes in a spreadsheet of print times and filament used.

We were honored to be among the first to see [Jason]’s incredible clock build at this year’s Midwest RepRap Festival. He would like to take it on tour this year to the nearby Maker Faires. If he can figure out how transport it safely, he’d like to show it at World Maker Faire in NYC.

Mechanical Clock Designed For A CNC Router Gets New Life Using A 3D Printer

June 10, 2014 by James Hobson 4 Comments

[Madis Kaasik] designed a clock a while back using Solid Edge (3D CAD) — but never got a chance to build it — until he became an exchange student at a university in Norway with access to a big industrial 3D printer!

He had originally intended for it to be cut out using a CNC router or with a laser cutter, but when discovered he could use the university’s 3D printer he decided to give it a shot — it’s actually the very first thing he’s ever printed! The designs had to be modified a little bit for 3D printing, but now that it’s done he’s also uploaded them to Thingiverse for anyone to use.

It took quite a bit of fine tuning with the pendulum, weights, and gears to get it ticking properly, but what [Madis] enjoyed most about this project was the realization of just how vast the possibilities of 3D printing are — he’s excited to begin his next big 3D printing endeavor!

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The Hour Of The 3D Printed Clock Draws Nigh

May 24, 2014 by Adam Fabio 15 Comments

Many have tried, but [Christoph Laimer] has succeeded in designing a working, (relatively) accurate clock nearly completely from 3D printed parts. Every gear, pulley, wheel and hand of [Christoph’s] clock is printed. Only a few screws, axles, a weight, and a string are non-printed. Even the crank to wind the clock is a 3D printed part.

[Christoph] designed his clock in Blender. It took quite a bit of design work to create parts that would work and be printable. Even more work was involved in printing over 100 failed prototype parts.

One might think that [Christoph] is using the latest printers from the likes of Makerbot or Utimaker to achieve this feat. It turns out he’s using a discontinued Rapman 3.2 printer. Further proof that even “older” printers are capable of great things! [Christoph] does run his printer rather slowly. Printing a single gear with 0.125 mm layers and a 0.4 mm nozzle takes him 2 or 3 hours.

Mechanically, the clock is gravity powered with an anchor escapement. Rather than a pendulum, [Christoph] chose to use a balance wheel and hairspring assembly to govern the escapement. Even the spring is printed from standard PLA. The weight is suspended from a pulley block. The clock isn’t particularly efficient. 70cm of height will run the clock for only 2 hours.

[Christoph’s] clock has proven to be accurate to within 1/4 second per hour. He hasn’t provided temperature stability data – but being PLA, we’d suggest not getting it too hot!

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