|Wind chimes add a pleasing symphony to any breezy garden, but it will be silent if placed in a sheltered nook, or kept inside a greenhouse, or whenever the wind dies down. This project will modify your wind chimes to make music using sunlight, a source of energy even more abundant than wind. With a few solar panels and a quiet motor, the chimes will jingle anywhere the sun shines, including indoors - underneath skylights, beside windows, in greenhouses, and so on. It won't keep you up at night, since its power source has disappeared, and whenever you need some peace and quiet during the day, the off button is always there.
Step 1: Prepare the ChimesThe chimes I selected for modification had one key feature: plenty of real estate on the top for new additions. The project is definitely possible with less space (or with the open ring designs), but you'll have to be a bit more creative to mount it all on there. My chimes were purchased at OSH. You can find them at most hardware stores, garden supply stores, and sometimes at patio furniture outlets. I snipped off the string for the knocker, and drilled a hole where the string was attached. The motor's shaft will go here.
Step 2: Mount the MotorMost small DC motors spin at hundreds or thousands of RPM, but we don't want our chimes to sound like "Flight of the Bumblebee", so the motor must be geared down to a manageable speed. I decided to use Jameco's Twin Motor Gearbox. While we won't be making use of the second motor, it provides the perfect gear ratio in a small, inexpensive package. If you have purchased robot kits from Jameco in the past, many of them have small gearboxes you can substitute here.
|To start, I removed the unnecessary second motor, setting it aside for use on future projects. There's a small tab for mounting the motor, but we want to mount it vertically, not horizontally. The tab is removed easily with a pair of pliers. This will allow the gearbox to lie flush against the surface, with the motor shaft poking through the hole you drilled. In order to mount it, we have to get access to two holes that are currently hidden by rollers. The same pliers can help you remove the rollers as well as the middle brackets holding them in place. After the holes are revealed, you can mount the motor with two small screws. Be sure that the screw heads are not so large that they will interfere with the gears.|
Step 3: Make the MechanismThe motor is in place so that the knocker will gently turn on its string. But to do that, the motor shaft will need a small lever arm. The arm should be slightly longer than the distance between the knocker and the tubes at rest. This is usually a very short distance. My lever arm measures half an inch. I made a disk by sawing off a short length of a wooden dowel. If you have components that already fit onto the shaft, such as a robot's wheel, that will work as well. I drilled one hole in center, a tad smaller than the motor shaft, so that it would fit snugly, and one hole near the edge, the same diameter as the string that held the knocker. I pushed the string through this hole, and tied a knot to hold it in place. Then I fitted the disk onto the motor shaft, along with a little glue.
To test the entire mechanical portion of the chime, I attached 3V of battery power to the motor leads. Lo and behold, the chimes began to ring out their song. Now it's time to wrestle with the electronics.
Step 4: Wire the PanelsSince the chimes are likely to hang in a place that is shadowed from directly above, I decided to attach the solar cells in a way that lets them catch the sun from an angle. I used two panels in this design to catch more rays, but with direct sunlight, one panel can do the job.
I sawed a piece of scrap wood in half to make a pair of wedges, and screwed those into the base. Instead of using glue to hold the solar cells in place, I put strips of adhesive-backed velcro on the wedges and the solar cells. That way I can move them around to catch the sun or transplant them for other projects without a big hassle.
The wiring is simplicity itself, since the motor is perfectly fine operating directly from the voltage provided by the cells. I also put in a switch I found in Jameco's switch grab bag.
Enjoy the Outcome
Find a place with plenty of direct sunlight and enjoy the solar-powered serenade. Here are a few more photographs of my finished solar chimes.
Adhesive-backed Velcro is available from craft stores.
Kevin Taylor is a first year student at UC Davis, majoring in Physics. He loves to repurpose old or broken things into a new creations through electronics.