Niklas Roy's Carton Clock keeps time with hot-glued drink cartons, paper straws and a milk carton full of nuts as its weight

Roy calls it “a purist experiment in trash bin horology,” and the purism is the whole joke. His earlier Glashütte Trash Clock admitted a few non-trash shortcuts, like PVC conduit axles and welding rods. This time he set out to cheat less, so the clockwork is cartons, glue, paper straws, skewers and string, with metal nuts as weights. A tripod and 3D-printed tools helped him build it but didn’t go into it.

The reason is a mood. “It feels like we are all experiencing the end of an era – and maybe it was a wasteful one,” Roy writes on the project page. A clock made of packaging is his way of saying that without saying it.

Version 1 was the proof of concept, and it only had a seconds hand. The escape wheel had five teeth, and the gearing used two plastic caps as gears, with 56 and 90 ridges for about 1.6, plus a friction drive into a carton disc, for roughly 6 overall. It ran for 7.5 minutes. “Since the escape wheel advances by half a tooth with every swing, it takes ten seconds for a full rotation,” he explains.

Version 2 is the full thing: hours, minutes and seconds. It has a 15-tooth escape wheel that turns once every 30 seconds, followed by a 2 reduction to the seconds hand. The motion work, the gearing that makes the hour hand crawl, is two stages of 3 and 4, a 12 reduction. Both stages have the same tooth sum of 40, which lets the hour and minute hands share one axis. The center wheel adds two more stages, 6 and 10, for the 60 seconds-to-minute ratio.

The pendulum is a double bob with metal nuts in either carton, and moving the weight shifts the center of mass for fine-tuning. The power comes from a milk carton filled with nuts hanging from a four-pulley block and tackle on up to 10 m of string. Going nuts, in the literal sense, is what keeps it running.

Cartons were a good choice for one reason and a bad one for another. Their laminate has cardboard, an aluminum layer and polyethylene films, and “PE sliding on PE has very low friction,” Roy writes, which is welcome in clockwork. The catch: “Unfortunately, hot glue doesn’t like to stick to PE very much – but using a lot of hot glue helps.” So the build is part gears and part glue gun.

It isn’t a perfect timekeeper. The pendulum never quite reached a one-second period. Adding weight to the lower carton eventually stopped the clock, so Roy increased the drive weight until the carton parts reached their limits. “In the end, I made my peace with the fact that the Carton Clock runs a little fast,” he writes. He also built two browser tools for the job: Cartontick, which designs escapements and glue jigs, and Cartongears, which designs gears, tools and jigs.

The page’s own timeline is the open question. Version 2 ran a little more than an hour, a long way from a clock you’d hang on a wall, and the weight had to be pushed right to the limit of what the cartons could take. Roy says the parts reached their limits, which leaves a build that works at the edge of what its own material allows.

Roy’s tools make the next one easier for anyone else with a recycling bin. The gears, the glue jigs and the escapement design are the hard parts, and he has put them in a browser, which lowers the cost of trying to beat 60 minutes.

Fast, but never late.