Niklas Roy - Glashütte Trash Clock

Mechanical Clockwork Glashütte, 2026 “Glashütte Trash Clock” is a fully functioning clockwork made from trash and other stuff that I found in Glashütte, Saxony. Since the mechanism just runs for about half an hour, it only displays seconds and minutes, striking a gong whenever the minute hand reaches the 12 o’clock position. As a little extra, the clock also triggers an external randomizer just before it runs out of energy. While working on this clock, I also invented a new time scale: GTC. It blends the concepts of GMT and UTC, and the Glashütte Trash Clock serves as its global reference clock. GTC reference clock Background Both my great-great-grandfather Henri Roy (1833–1910) and his son, my great-grandfather Eduard Roy (1860–1942), were Swiss watchmakers. They lived in La Chaux-de-Fonds, which is well known for its watchmaking tradition. Later in life, they emigrated to Herrnhut, a little town in Saxony, Germany, where they continued making clocks and watches. A pocket watch made by my great-great-grandfather Henri RoyPhotos: Martin Roy Glashütte, another small town in Saxony, is also famous among watch aficionados around the world. Some of the highest-quality mechanical timepieces are manufactured there. There is even a law protecting the designation of origin: only clocks and watches actually made there are allowed to bear the name “Glashütte/SA” on their dial. Close-up of my clock’s dial In 2026 I received a surprise email: NOMOS, a manufacturer of mechanical wristwatches, invited me to an artist residency in Glashütte. This seemed to be the perfect opportunity to follow in the footsteps of my ancestors and to try making a clock by myself. So I packed my suitcase and went to Glashütte. With me I brought some cutters, a compass, pliers, rulers, cutting mats, a few kilos of hot glue, a handful of zip ties, a bunch of different adhesive tapes and some books about horology. Packing my suitcase GDR textbook about mechanical clocks and watches Pendulum Among those books was “Mechanische Uhren” by Zdeněk Martínek and Jaroslav Řehoř, a vintage textbook for watchmakers. There I read how a pendulum can be used to measure time. I found it quite interesting to learn that the frequency at which a pendulum oscillates is only determined by its length (and the strength of gravity), while the weight at the end of the pendulum’s rod (which clockmakers call a bob) doesn’t really matter. A pendulum with a length of roughly one meter is called a seconds pendulum, because it takes one second to swing to one side and another second to swing back. Experimenting with a simple pendulum Therefore, my first practical experiment was to build a pendulum. In my extraordinary workspace, an old church, I found a step ladder to hang it from and a plastic water bottle to use as a bob. A wooden folding ruler made a perfect rod, as its length could be adjusted. My workspace: an old little church Dutch astronomer Christiaan Huygens (1629–1695) was the first one to describe the behavior of pendulums mathematically. He also constructed a working pendulum clock in 1656 and published this formula in his book “Horologium Oscillatorium”: T = 2 π · l g T is the time for one full back-and-forth swing — the period. l is the length of the pendulum, and g is the gravitational acceleration. As you can see, the strength of gravity plays a role in this equation, which means a pendulum clock made for Earth won’t work well on another planet with a different gravitational acceleration. I should also mention that Huygens’ formula describes the behavior of an ideal pendulum. The higher the pendulum swings, the less accurate the formula becomes. In fact, if you want to be really pedantic, a pendulum stops being ideal the moment it starts oscillating. So this formula is only exact for a pendulum that doesn't swing. But well, good luck building a pendulum clock with a non-swinging pendulum ;) Escapement In the next step, I had to keep the pendulum swinging for a long time, and the mechanism also had to count how often it swings. Thankfully, I didn’t have to invent anything, as all the parts needed are well described in the literature. I only had to figure out how to build them with the materials at hand. What I needed was an escapement, which consists of an escapement wheel and an anchor. Graham escapement with the pallets marked in redSource: “Mechanische Uhren” An escapement is quite clever because it does two things at the same time: connected to the anchor are two pallets, which block the escapement wheel alternately, letting it advance only half a tooth per swing of the pendulum — and with every release, the wheel also gives the pendulum a small push. Without that push, the pendulum would slow down and stop within minutes. When using a seconds pendulum, it makes sense to use an escapement wheel with 30 teeth: with one swing per second and half a tooth per swing, the wheel makes exactly one full rotation per minute. An indicator on this axle can then be used right away as a clock hand, showing the seconds. Building a paperclip escapement wheel Trying to build a reliable escapement out of trash was quite a challenge, as the parts had to be fairly precise and also strong. For the anchor, I used a carefully bent metal rod, and it turned out that paperclips make quite sturdy gear teeth for the escapement wheel. Art critics might suggest that the prominent use of paperclips in the mechanism could be read as a clear reference to Nick Bostrom’s paperclip maximizer, but this is no AI doomsday clock, and their extensive use in this project was for purely practical reasons. The paperclip escapement in motion. External force on the escapement wheel keeps the pendulum swinging. Energy Until then, the mechanism only worked when I pushed the pendulum or the escapement wheel by hand. To keep the wheel spinning on its own, I needed a way to store energy. Pendulum clocks usually rely on a weight suspended from a cord spooled around a barrel. In my design, this barrel drives the movement through the escapement axle. Barrel with spooled-up string on the back of the escapement axle. Some guides lead the string around the ladder. Building the barrel was simple, using some leftover cardboard packaging. For the weight, I filled an empty paint can with scrap metal I found at the NOMOS manufacturing facilities. I also salvaged an old toy construction kit from the roadside that happened to contain some pulleys — perfect for building a block and tackle, which halved the weight’s travel, so the clock could run twice as long before the weight hit the floor. This old construction kit I found on the streets in Glashütte contained some useful parts for building a block and a tackle. Two weights in a timelapse: the paint can powers the clock for about half an hour and the rubber boot runs the gong mechanism Reduction Drive The next step was building a reduction drive to display the minutes. The reduction is easy to calculate: 60 rotations of the seconds hand (the escapement axle) should cause the minute hand to spin once. It makes sense to do this in two stages, with an intermediate wheel, as every stage reverses the direction of rotation and it is desirable to have the minute hand spinning clockwise, too. Anything else would be awkward. After I cut some cardboard gears with questionable precision, I thought, why not just use simple friction wheels instead? Round discs could be cut much more easily than gears! The clock wouldn’t be precise anyway, so a little bit of slip between the wheels wouldn’t really matter. Making a friction wheel For each axle I used a simple hole as a bearing on one side and a fork on the other. The wheels were basically just lying on top of each other. To set the minute hand, I could simply lift the axle a bit, which disengaged its connection with the intermediate stage and let the minute hand spin freely. Setting the minute hand by lifting the axle Sound So far the clock worked well, but for my taste it lacked some joyful extras. Inspired by cuckoo clocks, I thought a little squeeze horn would be nice, but that turned out to be too hard to push, so I went for a glass bottle gong instead. It strikes whenever the minute hand reaches the 12 o’clock position. Apart from being triggered by the clock, the gong mechanism is completely independent, with its own energy source: another weight, this time a rubber boot, hanging from a string. Attempting to make a cuckoo clock with a squeeze horn Here’s how it works: the rubber boot’s string is spooled around a barrel (1). Mounted on the same axle are a drum (2) with two notches and a little lever that moves the gong hammer (3). There’s also a trigger lever (4) with two pins on its opposite side, which drop into the drum's notches and block its rotation. At the back of the axle sits a large fly (5), which slows down the rotation through air resistance. Its yellow flags are cut from a supermarket plastic bag. 1: Barrel   2: Drum   3: Hammer   4: Lever 5: Fly A cam plate on the minute wheel slowly lifts the trigger lever. This disengages the first pin and the drum spins a bit, until it is stopped right away by the second pin, which drops into the other notch. Clockmakers call this movement, which happens before the sound is triggered, the warning. During this phase, the hammer is pulled away from the glass bottle. Close-up of the cam plate lifting and dropping the lever. About two minutes later, the trigger lever drops off the cam back to its original position, pulling the second pin out of its notch. The first pin has already returned into the first notch — but that notch lets the drum spin on until it reaches its starting position again. The little hammer is released and strikes the bottle. This two-step design has a reason. Lifting the lever happens slowly, along the rising edge of the cam, so there is no clearly defined moment when the warning occurs. The drop, on the other hand, happens at a sharp