Japanese_Water_Fountain-opener

For more on microcontrollers and wearables, check out Make: Volume 43. Don't have this issue? Get it in the Maker Shed.
For more on microcontrollers and wearables, check out Make: Volume 43.
Don’t have this issue? Get it in the Maker Shed.

In Japanese, shishi-odoshi means “deer scarer.” This type of fountain slowly fills a hollow bamboo branch with water, and then suddenly tips — making a gentle knocking sound that will chase away any critters eating your garden. Many Zen gardens also use these rocking fountains as a meditation aid.

I built a small fountain to fit in a planter just 8″ across (see my original project here). Marty Marfin in the Make: Labs built one 3′ tall (shown above) that makes a beautiful focal point for an outdoor garden.

Here’s how to build your own, for about $50–$150 depending on the size you choose.

Project Steps

Select your bamboo

Each node is a barrier inside the bamboo. You’ll want one upright piece to have few or no nodes, as you’ll need to run tubing through it. For the rocking piece, you want a node in the middle, which will form the bottom of the scoop that fills with water.

NOTE: Working with bamboo is not like working with dimensional lumber. Bamboo surfaces are irregular, and size and shape change along the length. Be prepared to adjust instructions accordingly.

Determine dimensions

I built a small fountain to fit in a planter just 8″ across, and used 6 or 8 linear feet of bamboo. Marty Marfin in the Make: Labs built one 3′ tall (second photo) and used about 20′ total.

Whatever size you design, youʼll need a large-diameter piece for the top beam, 2 upright pieces that’ll fit into this beam, and a smaller-diameter piece for the spout, which also fits into the beam.

Choose another fairly large-diameter piece for the water scoop.

Cut and drill bamboo

Cut your beam and uprights to length. Measure the tops of the uprights carefully and drill holes in the beam to accept them.

Drill a third hole centered in the front of the beam, sized to accept the spout. But leave the spout piece extra long, as you’ll figure out the final length after some testing.

Test-fit the uprights, then drill a ¾” hole near the bottom of one of them, for routing the ½” tubing. I used Forstner bits; they leave beautifully clean holes.

Cut the water scoop piece so it’s got about the same length on either side of a node.

Cut steel rods

Use a hacksaw to cut a length of 3⁄16″ rod to span your uprights, plus a few inches on either side. This will be the axis of the water scoop.

Cut a shorter rod to fit between your uprights without touching; you’ll use this to test the pouring action.

Make the water scoop

Drill a 7/32″ hole just behind the central node and straight through the center of the bamboo.

Insert the shorter, test axis through the hole, and clamp it in a bench vise so the axis is straight up. Now trim one end of the bamboo at a shallow angle of about 30°, keeping the saw perpendicular to the ground. Just cut off a little; you may have to trim more later.

Thread the tubing

Feed the ½” tubing up through the upright you drilled, into the top beam, and out the spout. You can use a piece of rod or another tool to help guide the tubing.

TIP: Drill with an extra-long bit — or just hammer a piece of rebar — to punch through any nodes blocking your path.

Test the pouring action

Determining exactly where to mount the water scoop on the uprights is key. Dry-fit the bamboo frame together and use a temporary crosspiece of wood or bamboo to help support it.

Trim the tubing if needed, and connect it to the pump. My pump came with a valve that can partially restrict the water flow. You want it to pump as slowly as possible.

Run the pump and adjust the height of the water scoop between the 2 uprights to see how it works. You may need to adjust the length of the spout and/or the scoop so that water can pour from one to the other.

CAUTION: I recommend testing the pump outside — it’ll get splashy.

Mark and drill uprights

Once you’ve found the right placement for your water scoop, mark the uprights where the test axis is aligned.

Disassemble the frame and tubing, and drill 3⁄16″ holes at your marks. Reassemble.

Install the water scoop

Push the axis rod through the first upright, tapping gently with a hammer if needed. Cut 2 short pieces of small-diameter bamboo. You’ll use them as spacers to keep the scoop from moving too far from side to side. Place one spacer on the rod, then the scoop, then the second spacer.

Place one spacer on the rod, then the scoop, then the second spacer. Now push the rod all the way through the far side of the second upright.

If you wish, cover the exposed ends of the rod with 2 more short pieces of bamboo to match the spacers.

Make the knocker

In some traditional fountains, the water scoop tips down and strikes a rock or a basin to create the deer-scaring noise.

This one uses a lower crosspiece lashed to the frame to provide the desired knocking sound when the scoop tips back up. Test for desired location, then use thin rope to lash it on.

Troubleshoot and adjust

Check the flow of water and the rocking action. Adjust the spout angle if needed. I found I needed to straighten the vinyl tubing inside the spout by inserting a short collar of ½” PVC pipe to better direct the flow. Your mileage may vary.

If the water scoop doesn’t tip and dump after it fills, the back of the scoop weighs too much. You may have to saw some off to adjust the balance.

If it spills but then doesn’t flop back into position, the front end is too heavy. Trim the front or add some weight inside the back end.

Now put your rocking fountain in your garden to make a space that’s peaceful for you — and for your plants.

Thanks to Bamboo Sourcery (bamboosourcery.com) in Sebastopol, California, for the bamboo and photo location.