A vintage film camera with a bright light emitting diode shining through it, next to electronic equipment to measure the shutter speed

Clock Your Camera With This Shutter Speed Tester

February 7, 2023 by 25 Comments

Camera shutter speed is an essential adjustment in photography – along with the aperture, the shutter moderates the amount of light entering the camera. Older cameras (and some newer ones) use mechanical shutters that creep out-of-spec over the years, so [Dean Segovis] built a handy shutter speed tester.

With just a handful of basic components, this project is a great one for beginners to sink their teeth into. The tester is based around a photoresistor that measures light from another source (a flashlight) that travels through the camera body. When the shutter on the camera is released, the shutter speed can be measured and displayed on the OLED screen. An Arduino naturally handles all the computational duties. The whole thing can be easily assembled on a breadboard in just a couple of minutes.

The original project by [hiroshootsfilm] is over on Project Hub, however [Dean] takes a deeper dive with some code troubleshooting, as well as trying out a variety of old film cameras with the breadboard tester. His testing revealed that the photoresistor was better able to detect shutter speed when the camera lens was removed, which is a hot tip for anyone else that wants to try this.

While it’s not surprising that these older cameras are having trouble with their mechanical shutters, this little tester would be an invaluable tool when it comes time to start tweaking shutter mechanisms. If this project has brought out the shutterbug in you, make sure to check out this brain transplant for a Polaroid 100-series Packfilm camera that we covered way back in 2011.

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Ikea Clock Gets Wanderlust

February 6, 2023 by 29 Comments

We always enjoy unique clocks, and a recent 3D print from [David Kingsman] caught our eye. It converts an Ikea clock into a very unusual-looking “wandering hour” clock that uses a Geneva drive to show a very dynamic view of the current time. The concept is based on an earlier wandering clock, but [David] utilized a different mechanism.

To read the clock, you note which hour numeral is in range of the “minute arc” and read the time directly. So if the 12 hour is over the 20-minute mark, the time is 12:20. Besides the clock, you need a fair number of printed parts, although they all look like relatively simple prints. You’ll also need 13 bearings and some metric hardware. A piece of cardboard used for the face rounds out the build.

Modifying the clock is more than just taking it apart. There is a template file to print, and you’ll need to align it and drill holes as indicated.

If you haven’t seen a Geneva drive before, it translates a continuous rotation into intermittent rotation. This isn’t the first clock we’ve seen use this kind of drive, although the last one we saw represented time differently. If you want something even more mechanical, try a chain-driven clock.

An Atomic Pendulum Clock Accurate Enough For CERN

January 28, 2023 by 31 Comments

That big grandfather clock in the library might be an impressive piece of mechanical ingenuity, and an even better example of fine cabinetry, but we’d expect that the accuracy of a pendulum timepiece would be limited to a sizable fraction of a minute per day. Unless, of course, you work at CERN and built  “the most accurate pendulum clock on the planet.”

While we’re in no position to judge [Daniel Valuch]’s claim, we’re certainly inclined to believe him, mainly because the 1950s-era Czechoslovakian pendulum clock his project was based on, the Elektročas HH3, was built specifically as a master clock for labs, power plants, and broadcast use. The pendulum of this mid-century beauty is made of the alloy invar, selected for its exceptionally low coefficient of thermal expansion. This ensures the pendulum doesn’t change length with temperature, but it still only brings the clock into the 0.1 second/day range.

Clearly that’s not good enough for a clock at CERN, the European Laboratory for Nuclear Research, where [Daniel] works as an RF engineer. With access to a 10-MHz timebase from a cesium fountain atomic clock — no less a clock than the one that’s used to define the SI second, by the way — [Daniel] looked for ways to sync the clock up to it. Now, we know what you’re thinking — he must have used some kind of PLL to give an electromagnetic “kick” to the bob to trim the pendulum’s period. Good guess on the PLL, but the trimming method is a little cruder — [Daniel] uses a stepper motor attached to the clock’s frame to pay out or retract a length of fine chain into a cardboard dish attached to the pendulum’s rod. The change in mass changes the pendulum’s center of gravity, which changes its effective length, and allows the clock to be tuned a couple of seconds per day.

It seems like [Daniel] is claiming that his chain-corrected clock won’t drift more than a second from the cesium clock for 158 million years. Again, we’ll take his word for it, but it’s a wonderfully ad hoc approach to tuning the clock, and we appreciate its simplicity.

Something’s Rotating In The State Of Denmark: A Clock

January 4, 2023 by 15 Comments

If you visit the Copenhagen City Hall, you’ll see an ornate mechanical clock. By itself, this is unremarkable, of course. There are plenty of ornate clocks in city halls around the world, but this one has a fascinating backstory that starts with a locksmith named Jan Jens Olsen. Unfortunately, Jens didn’t actually complete the clock before his death. It would take 12 years to put together the 15,448 individual parts. However, he did manage to see most of the clock that he had been designing for 50 years put together.

Jens was 60 when he started constructing the clock, but the story starts when he was only 25. In Strasbourg, the young locksmith saw an astronomical clock with a perpetual calendar in a cathedral. He was fascinated and returned several times to study the mechanism. Around the age of 30, Jens had moved to watchmaking and had a keen interest in astronomy — he was a founding member of the Danish Astronomical Society. Perhaps it was the combination of these two interests that made it inevitable that he would want to build a precise astronomically-correct clock.

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A wall clock made from wires and electronic components

Form Follows Function In This Circuit Sculpture Clock

December 29, 2022 by 5 Comments

Electronic components are strictly functional objects: their appearance is determined by the function they’re meant to fulfil. But that doesn’t mean there’s no beauty in them. In fact, a whole discipline called circuit sculpture exists that aims to make beautiful shapes out of nothing more than electronic components and wires. Today we can show you [Maarten Tromp]’s latest work in this field: a wall-mounted clock that he’s christened the Clock Sculpture.

The clock’s main structure consists of two concentric rings made from galvanized steel wire, held together by twelve spokes. All components are soldered directly onto those two rings, with no additional mechanical support. Steel isn’t the greatest material for soldering to, but [Maarten] managed to make it work with a high-wattage soldering iron and a bit of plumbers’ flux.

The overall design is simple but clever: the outer ring holds 60 LEDs to indicate the minutes, with every fifth LED always illuminated dimly in order to provide a background reference in dark conditions. There are 24 LEDs on the inner ring to indicate the twelve hours as well as the “half-hours” in between. Without these, the dial would look a bit odd at 30 minutes past the hour.

Detail of a circuit sculpture clockA mains transformer, plus a single diode, a buffer capacitor and a 7805 regulator form a simple DC power supply, with its negative terminal connected to the steel frame. Time is kept by an ATtiny13A that counts mains frequency pulses. There’s no way to adjust the time: you’ll have to plug in the clock exactly at noon or midnight in order to synchronize it with the outside world. A crude method perhaps, but one that fits well with the clock’s bare-bones aesthetic.

The individual LEDs are driven by a set of twelve 74HC595 shift registers, all mounted dead-bug style between the two rings. Signals and power are carried between the chips by inconspicuous grey wires taken from old IDE cables; this gives the clock a clean, uncluttered appearance. [Maarten] has had the sculpture clock in his office for several months and while it apparently took some time to get used to, he claims it’s easy to read in bright and dark conditions.

Circuit sculpture has formed the basis for several stunning clock projects: this Tie Fighter-shaped clock for instance, or this insanely complex LED clock. Our 2020 Circuit Sculpture contest yielded many breathtaking designs, too.

A clock based on magnetic viewing film

Magnet Clock Makes Field Lines Visible

December 14, 2022 by 1 Comment

The traditional method for visualizing magnetic fields, which your science teacher probably demonstrated at some point, is to sprinkle some iron filings onto a piece of paper and hold it over a magnet. It’s a bit of a messy process though, and nowadays there’s a more modern method available in the form of magnetic viewing films. These work thanks to tiny nickel particles suspended in an oily medium, and come in very handy if you want to examine, say, the magnetic field pattern of a DC electric motor. [Moritz v. Sivers] had another idea for this magic material however, and used it to make a Magnet Viewing Clock.

A DIY clock, opened upThe clock’s front panel looks very similar to a large monochrome LCD, but is actually a big slab of magnetic viewing film. Four disks are mounted behind it, each carrying number-shaped magnetic stickers that are cleverly hidden from view. An Arduino Uno keeps track of time through a real-time clock and operates four stepper motors that rotate the number wheels. When they move into position, their magnetic stickers become visible through the film and you can read the time.

The clock’s mechanical parts are 3D printed, while the digits were cut from a sheet of sticky magnetic foil using a vinyl cutter. If you’d like to try making something similar you’re in luck: [Moritz] made the design files and the Arduino sketch available on his GitHub page. Magnetic viewing films are pretty neat things to play with anyway, and can even be used to read hidden messages.

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Quirky Complicated Clock Piques Constructor’s Curiosity

July 19, 2022 by 2 Comments
The Clock that served as inspiration for the garberPark Clock

Have you ever observed the project of another hacker and thought to yourself “I have got to have one of those!”? If so, you’re in good company with hacker [garberPark], the maker of the unusual chain clock seen in the video below the break.

While on a stroll past the Chicago Avenue Fire Arts Center in Minneapolis, MN, [garberPark] was transfixed by the clock seen to the right here. In the clock, two motors each drive a chain that has numbers attached to it, and the number at the top displays the current time. It wasn’t long before [garberPark] observed his own lack of such a clock. So they did what any hacker will do: they made their own version!

Using an ESP8266, and Arduino, and some other basic electronics, they put together a horizontal interpretation of the clock they saw. Rather than being continuous rotation, limit switches keep things in line while the ESP8266’s NTP keep things in time. Salvaged scanner stepper motors provide locomotion, and what appear to be bicycle cranks and chains work in harmony with cutoff license plates to display the current time- but only if there’s somebody around to observe it; A very nice touch and great attention to detail!

If you enjoyed this, you’ll love the Sprocket and Chain clock we featured a few months back.

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