I've always wanted a sprinkler I could take out for a spin.
The giant sprinkler is an amazing shin-wetting device using a wee bit of inertia and centripetal force. It works great in shallow pools, lakes, tubs, and densely packed crowds! Make one and see the truly amazing paths of water as they climb up and out of tubes and spray all over.
- What: Giant Sprinkler
- Why: the concrete isn't going to water itself
- Concepts: forces, inertia, pumps, hydrology
- Time: ~ 20 minutes to make, forever to play
- Cost: ~$5
- Wide wood dowel (I used 4' of 1 1/4")
- Thinner wood dowel (I used 12" of 1/2")
- Thin rigid plastic tube (I used 1/4")
- Duct Tape
- Clamps x 2
- Scrap wood
- Plastic knife
Step 1: Shave a Dowel
Let's bring this to a point!
You can choose your favorite method for making a pointy dowel, be it by saw, sander, or whittle. My personal favorite is this method of turning a sander into a giant pencil sharpener. Clamp down straight piece of wood at an angle. Feed your wider dowel so it hits the sander at an angle, and rotate. You'll end up with a point in no time at all.
Step 2: Drill a Hole
Clamp it in and drill a hole large enough for the skinny dowel to snugly fit through. You'll want to make sure you go as close to the center as possible, and make the the hole just a couple inches above the large dowel's tip.
Step 3: The Crossbeam
Chop off a piece of the skinny dowel that's about 12" long. Bring it to your sanding block, but this time instead of rotating it, simply sand it at an angle. Repeat the process on the other side so that you end up with a "V" formation on the two sides. At the end, wriggle it through your larger dowel and make the V face downward.
Step 4: Tube Time!
Nab those tubes and cut two approximately lengths with a plastic saw. You can change the size, but I found about 12" to work out pretty well. Use duct tape to attach them to the crossbeam, and wrap so they sit snug. They can come down and touch the large dowel near the base for support as long as the tubes are exposed.
If it's not fitting correctly, simply cut your tubes to a different length or try re-making the "V" of the crossbeam.
Step 5: Sprinkle All the Things
This concrete isn't going to sprinkle itself, you know.
Place the tip of your dowel in a deepish container of water with a wide top. Take it away, and spin to see water fly out everywhere. You can see beautiful patterns start to emerge in the shape of the water streams as they climb up and out of your sprinkler!
Things to try:
- Tube Length - try adjusting the tube length, what happens if they're uneven?
- Tube Angle - what happens when the tubes are more vertical?
- Flexibility - try the sprinkler with flexible tubing. What paths can you make for the water?
- Spinning - what method can you devise to help you spin the dowel even faster
- Photography - try to capture a great moment on camera and have fun trying.
Have fun, take it for a spin, and keep exploring.