Laminar Flow Water Fountain

By Larry Cotton
Category: Fun & Games, Gardening, Home
Time Required: A weekend
Difficulty: Moderate

By Larry Cotton and Phil Bowie

Laminar-flow water charms and fascinates. It behaves quite differently from ordinary turbulent water, such as the flow from a faucet or garden hose. A laminar stream is so perfect it could pass for a glass rod. It doesn’t splash upon hitting a surface, it will conduct light like a fiber-optic cable, and it’s so cohesive, it will enwrap and levitate a smooth sphere, even at a surprising angle to the vertical.

In 2011, we drove 600 miles from our North Carolina homes to Disney’s Epcot theme park to study the “Leap Frog” fountain, which chops a laminar stream into arcs, creating impish, cavorting water creatures. We’ve been obsessed with laminar flow phenomena ever since, joining an online cult of experimenters.

We have achieved laminar flow simply and inexpensively by making a nozzle from a big plastic peanut butter jar, scrub pads, drinking straws, and standard PVC pipe and hose fittings. A fine way to show off its elegant stream is to build a fountain using this nozzle as its heart. It’s easy to make, and can produce captivating shapes or even levitate lightweight spheres.

Steps

Step #1: Build the nozzle.

For more details on the different fountain pieces, download the templates and assembly diagrams.
Drill a 1" hole in the center of the bottom of an empty 40oz plastic peanut butter jar.
Cut the 4" pipe to make 2 spacers as shown, using a band saw or jigsaw. Bend the tabs inward with needlenose pliers, then press them down with the pliers tips to about 90°.
Use scissors to cut the drinking straws into approximately 200 segments about 1 3⁄4" long. Cut the scrub pads into 5 disks 3 3⁄4" in diameter and 3 disks 1" in diameter. Use shears or tinsnips to cut 2 disks from the aluminum screen, also 3 3⁄4" in diameter.
NOTE: Keep the ends of the straws even. Insert spacers by compressing them until the ends overlap, then pushing them through the jar opening.
Attach the 3⁄4" plumbing fittings to the jar bottom as shown, taking note that the outside fitting has 2 different threads.
Fill the jar as shown with the scrub pad disks, screen disks, drinking straw segments, and the 2 spacers you made.

Conclusion

This nozzle, pump, and filter combination will produce a beautiful, large, clear dome. Position your fountain in a sheltered area away from wind, because domes can assume uncontainable (though interesting) shapes.

Adjust the faucet to control the size of the dome so the water is collected in the basin.

You may want to play with different deflectors, or try levitating different spheres. Add LEDs or other lights for night- time viewing. Cruise a few of the websites devoted to laminar-flow water features for endless ideas. A particularly good one is http://laminar.forumotion.com.

And prepare to become addicted.

This project first appeared in MAKE Volume 32, page 124.