This simple solar robot project utilizes a solar engine circuit. The small solar cell can’t generate enough power to move the motor, so what the miniball does is store the power in a capacitor. When there’s enough power stored, it releases the power into the motor to make the ball move around.
The mechanical parts you’ll need for the solar powered miniball are:
- 1 – 80mm transparent plastic sphere (You can buy this from a hobby shop or arts and crafts store.)
- 1 – High-efficiency coreless motor*
- 1 – Motor mounting clip*
- 3 – Rubber wheels on nylon hubs*
- 2 – Paper clips
The electronic parts are:
- 1 – 37x33mm Solarbotics solar cell*
- 1 – 0.35F 2.5V Capacitor*
- 1 – 6.8uF Tantalum capacitor*
- 1 – 3904 Transistor*
- 1 – 1381 Voltage trigger*
- 1 – Signal diode 1N914*
- 1 – length twisted red/black wire
- * parts sold in bundle by Solarbotics (Click here to get the bundle.)
The tools needed for the solar powered miniball DIY project are:
- Soldering iron
- Needle-nose pliers
- Flush cutters
- Safety glasses
Here are the procedures for building the solar powered miniball:
- Solder all parts to the solar cell. If you bought the bundle from Solarbotics, it comes with instructions regarding what to solder and where.
- Place the components on the printed circuit board, making sure you get the polarity of the capacitor right. This means putting the positive lead in the right hole. Also, use a sleeve of a breadboard wire to isolate the positive lead and prevent it from contacting the diode.
- Cut a wheel into two pieces.
- Straighten the paperclip and bend it to hold both wheels.
- Use a breadboard wire to make a guide for the wheels so that they will not slide too far.
- Place the rubber wheel and close the wheel guide.
- Use a fuse holder (included in the bundle from Solarbotics) to mount the motor. Use the pliers and squeeze the fuse holder over the wire so it will stay in place.
- Bend the paperclip frame so it will fit in the plastic sphere.
- Strip the insulation off the wire and save the sleeve. Push the sleeve into the motor and slide the wheel into it.
- Cip the motor in the fuse holder and place the assembly in the sphere.
- Solder the wheel frame to the solar cell.
- Use the snipping tool to cut the tabs off the sphere.
- Place the robot into the ball. You’re done!
This is how you make a DIY solar powered miniball. If your miniball flips upside down and stops moving, you can make a long paper clip and place it erect without touching the top of the plastic ball.