water

152 Articles

3D-Printing A Full-Sized Kayak In Under A Day

August 12, 2025 by 22 Comments

If you want to get active out on the water, you could buy a new kayak, or hunt one down on Craigslist, Or, you could follow [Ivan Miranda]’s example, and print one out instead.

[Ivan] is uniquely well positioned to pursue a build like this. That’s because he has a massive 3D printer which uses a treadmill as a bed. It’s perfect for building long, thin things, and a kayak fits the bill perfectly. [Ivan] has actually printed a kayak before, but it took an excruciating 7 days to finish. This time, he wanted to go faster. He made some extruder tweaks that would allow his treadmill printer to go much faster, and improved the design to use as much of the belt width as possible. With the new setup capable of extruding over 800 grams of plastic per hour, [Ivan] then found a whole bunch of new issues thanks to the amount of heat involved. He steps through the issues one at a time until he has a setup capable of extruding an entire kayak in less than 24 hours.

This isn’t just a dive into 3D printer tech, though. It’s also about watercraft! [Ivan] finishes the print with a sander and a 3D pen to clean up some imperfections. The body is also filled with foam in key areas, and coated with epoxy to make it watertight. It’s not the easiest craft to handle, and probably isn’t what you’d choose for ocean use. It’s too narrow, and wounds [Ivan] when he tries to get in. It might be a floating and functional kayak, just barely, for a smaller individual, but [Ivan] suggests he’ll need to make changes if he were to actually use this thing properly.

Overall, it’s a project that shows you can 3D print big things quite quickly with the right printer, and that maritime engineering principles are key for producing viable watercraft. Video after the break.

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2025 One Hertz Challenge: Drop The Beat (But Only At 60 BPM)

July 28, 2025 by 1 Comment

Mankind has been using water to mark the passage of time for thousands of years. From dripping stone pots in Ancient Egypt to the more mechanically-complicated Greco-Roman Clepsydrae, the history of timekeeping is a wet one — and it makes sense. As an incompressible fluid, water flows in very predictable patterns. If you fill a leaky pot with water and it takes an hour to drain, it will also take an hour the next time you try. One Hertz Challenge entrant [johnowhitaker] took this idea in a different direction, however, with an electromechanical clock that uses dripping water as an indicator.

This clock uses a solenoid to briefly pop the plunger out of a water-filled syringe. This allows a drop to fall from the tip, into a waiting beaker. In addition to the satisfying audio indication this produces, [johnowhitaker] added a bit of food coloring to the dripping water for visual flair. The entire thing is controlled by a Raspberry Pi Pico and a motor driver board, so if you’ve got some spare parts lying about and would like to build your own be sure to head over to the project page and grab the source code.

While this clock isn’t exactly here for a long time (either the syringe will eventually empty or the beaker will overflow), it’s certainly here for a good time. [John] and commenters on his project even have ideas for the next steps: a 1/60 Hz beaker changer, and a 1/600 Hz spill cleaner. Even so, the first couple of drops hitting the beaker produce a lovely lava lamp-esque cloud that is a joy to watch and has us thinking about other microfluidics projects we’ve seen.

And remember — it’s not too late to enter the 2025 One Hertz Challenge!

Big Chemistry: Seawater Desalination

June 16, 2025 by 40 Comments

For a world covered in oceans, getting a drink of water on Planet Earth can be surprisingly tricky. Fresh water is hard to come by even on our water world, so much so that most sources are better measured in parts per million than percentages; add together every freshwater lake, river, and stream in the world, and you’d be looking at a mere 0.0066% of all the water on Earth.

Of course, what that really says is that our endowment of saltwater is truly staggering. We have over 1.3 billion cubic kilometers of the stuff, most of it easily accessible to the billion or so people who live within 10 kilometers of a coastline. Untreated, though, saltwater isn’t of much direct use to humans, since we, our domestic animals, and pretty much all our crops thirst only for water a hundred times less saline than seawater.

While nature solved the problem of desalination a long time ago, the natural water cycle turns seawater into freshwater at too slow a pace or in the wrong locations for our needs. While there are simple methods for getting the salt out of seawater, such as distillation, processing seawater on a scale that can provide even a medium-sized city with a steady source of potable water is definitely a job for Big Chemistry.

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3D Filament lizards show decomposable joints

Sustainable 3D Prints With Decomposable Filaments

May 30, 2025 by 24 Comments

What if you could design your 3D print to fall apart on purpose? That’s the curious promise of a new paper from CHI 2025, which brings a serious hacker vibe to the sustainability problem of multi-material 3D printing. Titled Enabling Recycling of Multi-Material 3D Printed Objects through Computational Design and Disassembly by Dissolution, it proposes a technique that lets complex prints disassemble themselves via water-soluble seams. Just a bit of H2O is needed, no drills or pliers.

At its core, this method builds dissolvable interfaces between materials like PLA and TPU using water-soluble PVA. Their algorithm auto-generates jointed seams (think shrink-wrap meets mushroom pegs) that don’t interfere with the part’s function. Once printed, the object behaves like any ordinary 3D creation. But at end-of-life, a water bath breaks it down into clean, separable materials, ready for recycling. That gives 90% material recovery, and over 50% reduction in carbon emissions.

This is the research – call it a very, very well documented hack – we need more of. It’s climate-conscious and machine-savvy. If you’re into computational fabrication or environmental tinkering, it’s worth your time. Hats off to [Wen, Bae, and Rivera] for turning what might otherwise be considered a failure into a feature.

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Ultra-Low Power Soil Moisture Sensor

March 18, 2025 by 13 Comments

Electricity can be a pretty handy tool when it stays within the bounds of its wiring. It’s largely responsible for our modern world and its applications are endless. When it’s not running in wires or electronics though, things can get much more complicated even for things that seem simple on the surface. For example, measuring moisture in soil seems straightforward, but corrosion presents immediate problems. To combat the problems with measuring things in the natural world with electricity, [David] built this capacitive soil moisture sensor which also has the benefit of using an extremely small amount of energy to operate.

The sensor is based on an STM32 microcontroller, in this case one specifically optimized for low-power applications. The other low-power key to this build is the small seven-segment e-ink display. The segments are oriented as horizontal lines, making this a great indicator for measuring a varying gradient of any type. The microcontroller only wakes up every 15 minutes, takes a measurement, and then updates the display before going back to sleep.

To solve the problem resistive moisture sensors have where they’re directly in contact with damp conditions and rapidly corrode, [David] is using a capacitive sensor instead which measures a changing capacitance as moisture changes. This allows the contacts to be much more isolated from the environment. The sensor has been up and running for a few months now with the coin cell driving the system still going strong and the house plants still alive and properly watered. Of course if you’re looking to take your houseplant game to the next level you could always build a hydroponics system which automates not only the watering of plants but everything else as well.

Learning About The Flume Water Monitor

December 18, 2024 by 10 Comments

The itch to investigate lurks within all us hackers. Sometimes, you just have to pull something apart to learn how it works. [Stephen Crosby] found himself doing just that when he got his hands on a Flume water monitor.

[Stephen] came by the monitor thanks to a city rebate, which lowered the cost of the Flume device. It consists of two main components: a sensor which is strapped to the water meter, and a separate “bridge” device that receives information from the sensor and delivers it to Flume servers via WiFi. There’s a useful API for customers, and it’s even able to integrate with a Home Assistant plugin. [Stephen] hoped to learn more about the device so he could scrape raw data himself, without having to rely on Flume’s servers.

Through his reverse engineering efforts, [Stephen] was able to glean how the system worked. He guides us through the basic components of the battery-powered magnetometer sensor, which senses the motion of metering components in the water meter. He also explains how it communicates with a packet radio module to the main “bridge” device, and elucidates how he came to decompile the bridge’s software.

When he sent this one in, [Stephen] mentioned the considerable effort that went into reverse engineering the system was “a very poor use” of his time — but we’d beg to differ. In our book, taking on a new project is always worthwhile if you learned something along the way. Meanwhile, if you’ve been pulling apart some weird esoteric commercial device, don’t hesitate to let us know what you found!

3D-Printed Boat Feeds The Fishes

December 16, 2024 by No comments

In most natural environments, fish are able to feed themselves. However, if you wanted to help them out with some extra food, you could always build a 3D-printed boat to do the job for you, as [gokux] did.

The concept is simple enough—it’s a small radio-controlled boat that gets around the water with the aid of two paddle wheels. Driven together, the paddle wheels provide thrust, and driven in opposite directions, they provide steering. A SeeedStudio XIAO ESP32 is the brains of the operation. It listens into commands from the controller and runs the paddle drive motors with the aid of a DRV8833 motor driver module. The custom radio controller is it itself running on another ESP32, and [gokux] built it with a nice industrial style joystick which looks very satisfying to use. The two ESP32s use their onboard wireless hardware to communicate, which keeps things nicely integrated. The boat is able to putter around on the water’s surface, while using a servo-driven to deliver small doses of food when desired.

It’s a neat build, and shows just what you can whip up when you put your 3D printer to good use. If you’d like to build a bigger plastic watercraft, though, you can do that too. Video after the break.

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