Prerequisites / Parts List
This guide will be for hobbyists who wish to construct a small scaled solar powered car for any occasion. This car will be designed to be as light as possible to maximize the acceleration and top speed achieved by the limited capabilities of the selected solar cells and motor. Those who wish to construct a car following this design will need to acquire the same components used or components similar in size and capability. Furthermore, closely following this design will require the use of a 3D printer for the printing of the vehicle's chassis. Those who wish to successfully complete this project will also need to have basic soldering and hot gluing skills.
2 x Solar Cell - Model Number: SOL4N Velleman
1 x DC Motor - Model Number: RF-500TB-18280
3D printer and filament - Any Type
4 x Velcro Dots
2 x Large wheels - DuBro 2.50" Micro Sport Wheels
1 x Small wheel - DuBro 1.23" Micro Sport Wheel
Hot glue gun with glue sticks - Any Type
Soldering Iron - 15W or higher
Wire Strippers - Any Type
1 x 150mm by 3mm Stainless Steel Cylinder Linear Rail Round Rod Shaft
Step 1: Building the Chassis
For the first step of this design, the main structure of the solar car must be designed. Attached to this step is an outline of the 3D design of the base that was used for this car. This will be a .stl file which may be uploaded to a 3D printer. If there is no 3D printer available, this base may still be created by any type of material such as popsicle sticks. This same base design is just an example and does not have to replicated exactly the same. Any base structure should be suitable as long as the solar panel will fit on top. For this particular 3D print, we used an infill setting of only 10% to help minimize weight.
Step 2: Acquiring the Solar Cells, Motor, Wheels, and Axle
1) The Solar Panel and Motor were already provided for our use. Builders can either acquire the same motor and solar cells by purchasing them online or by sourcing ones which are similar in capacity.
2 x SOL4N Small Solar Cell: https://megadepot.com/product/velleman-sol4n-small...
1 x 3V DC Motor: https://www.amazon.com/Motor-2104-RPM-1-3V-Range/d...
2) Acquire the axle to be used with the chassis.
Stainless Steel Cylinder Linear Rail Round Rod Shaft: https://www.amazon.com/10Pcs-Stainless-Steel-Cylin...
3) Acquire the same wheels or wheels which are similar in size and design so that they work properly with the rest of the car.
2 x 2.5" Wheels: https://www.amazon.com/Du-Bro-250MS-Micro-Sport-2-...
Step 3: Attaching the Wheels and Axle
1. Prepare the hot glue gun by plugging it in and attaching the glue stick. Place a paper towel down under the work-space.
2. Once the glue is hot, slide one large wheel onto the very end of the axle while simultaneously gluing directly onto the axle to keep the wheel in place.
3. Slide the other end of the axle into the body of the car in its designated cutout in the frame.
4. Once the axle is all the way through so that the glued wheel is almost touching the body, glue the second large wheel onto the opposite end of the axle using the same process.
5. To prevent the axle from sliding, place a layer of glue on the exposed axle in the center of the frame. Make sure that the axle is now stable, if not add another layer of glue being careful not the glue the frame to the axle.
6. For the third wheel, use hot glue to attach it directly on the end of the motor shaft. Make sure that the motor is centered on the wheel and that the wheel is not tilted.
Step 4: Attaching the Motor and Solar Cells
Solar Cell and Velcro Dot Placement
1. Combine two Velcro dots together by connecting the hooks of one dot to the loops of the other so that both sticky sides are facing out.
2. Repeat part 1 two more times so that there are 3 sets of combined Velcro dots located like the picture.
3. Establish the upward side of the frame indicated by the indent for the motor.
4. Attach one of the Velcro dot pairs to the frame so the pair is centered and on the opposite side from the motor indent. Make sure one of the sticky sides of the Velcro dot pair is be facing upward.
5. Stick one of the solar cells on the Velcro dot pair so that the long side of the solar cell goes from wheel to wheel and half of the solar cell hangs off the end of the frame.
6. Attach the other Velcro dot pairs on opposite sides of the frame so that each are next to one of the wheels and 1 or 2 cm away from the already placed solar cell.
7. Stick the next solar cell to the two exposed Velcro dot pairs in the same orientation as the first solar cell.
1. Disperse a dab of hot glue onto the indent of the frame so that the motor can be attached to the frame.
2. Place the motor in the indent so that the wheel is centered between the gap in the frame and is not tilted with respect to the frame.
*If it is desired to make the bond between the motor and frame stronger, glue can be placed along the creases between the motor and the frame.
Step 5: Wiring the Motor and Solar Cells
Warning: If you have never soldered wires before, be sure to watch this quick video above that gives you some simple techniques on how to solder.
Motor Direction Test
1. Strip the ends of the solar panels wire if they have not already been.
2. Place the car under a solar light and touch the two positive wires from the solar panels to one terminal of the motor and the two negative wires to the opposite terminal.
*If the car goes in the direction so the solar panels are in the front then proceed. If not, then swap the wire connections.
Soldering the Connections
1. Twist the two positive wires from the solar panels together and solder them to the designated terminal hole.
2. Do the same for the two negative wires soldering them to their designated terminal hole.
*If necessary, glue the wire to the bottom of the frame so that it is not just sticking out, this is demonstrated in the video.
Step 6: Testing the Solar Car
1. Find a flat surface that is long enough to allow the car to roll for approximately 5 -10 seconds.
2. Place the solar car on the ground so that the car will follow a path parallel with the walls of the hallway.
3. Turn the portable solar light and shine it closely to the car being sure to follow it as it rolls the whole way down the hallway.
4. Observe of the results and troubleshoot if the car does not work as expected.
*If the car does not roll, make sure that the soldering points are correct by reviewing the wiring step or the video. If the car does not roll straight, be sure that the center wheel is not tilted and that the axle is stable.