Introduction: How to Assemble DIY Solar Toy Car Kit

About: i like to mess around with cars and computers. visit my youtube channel!

Looking to teach renewable energy to your kid? Forget science fair, this is a cheap solar car toy kit that you can buy for less than 5$ and never requires battery to play. For the same amount of money you can buy a built model, but now where's the fun in that??

I recently obtained a few solar car toy for kids in dollar store, and I am surprised that this one despite being the popular model doesn't come with a clear instruction manual. So here it is, a step-by-step guide along with pictures and my personal review.

+ Cheap, sometimes can be had for less than 3$
+ Open configuration, either RWD or FWD is possible
+ Big diameter tires means it can handle small obstacles

- Cheaply built, do not expect precision
- Tiny solar panel means only usable in direct scorching sunlight (or really powerful flashlight)
- Chassis requires screws even though it adds weight

Step 1: Let's Get Started

My kit comes in a resealable plastic bag. There is of course no instruction manual and list of parts, so here is the parts required:

- 4x plastic tires
- 1x green plastic chassis
- 1x solar panel
- 1x electric motor
- 1x big white reduction gear
- 1x tiny screwdriver (philips head)
- 4x silver bracket
- 4x tiny orange plastic bushing
- 2x metal rod for wheels
- 10x screw and nut (only 8pcs are required)
- 1x instruction manual which is not helpful


First up, we have to install the metal bracket to the chassis. We have total of 4 metal brackets which will be held by 8 bolts. You can use the supplied screwdriver to install these.

My chassis doesn't look exactly like the image in the instruction manual supplied, but you can install it in any direction so you can start by putting 2 screws into the bracket and chassis [IMG 3]. Place the nut and tighten all the screws until it looks like image 5-6.

Step 2: Install Wheels and Axles

Now we have to install the wheels to the chassis.

Insert the reduction gear into the metal rod. Expect some pushing force to get the gear inside as the rod. Do not expect precision level of Tamiya mini racer kit car, as this is just cheap chinese toy kit.

Install wheels on driving axle:

[IMG 1-4]
Insert reduction gear
Insert orange plastic bushing
Insert one plastic wheel
Insert the axle into the chassis through the metal bracket
Insert orange plastic bushing
Insert one plastic wheel for the opposite side

Remember to not install this axle too tightly, as the friction of this non-precision parts will cause friction.

Install wheels on free axle:

[IMG 5-8]
Insert orange plastic bushing
Insert one plastic wheel
Insert the axle into the chassis through the metal bracket
Insert orange plastic bushing
Insert one plastic wheel for the opposite side

Your kit car should look like the last image. Do not worry about the FWD or RWD configuration now because it will be determined by the polarity of the wire coming into the electric motor.

Step 3: Electrical Connections

Now, you will need a wire-stripper to strip two wires coming from the solar panel. Because the motor has no polarity marking, I suggest you do a trial and error run to achieve the driving configuration of your choice: FWD or RWD.

Cut excess wire according to length
Strip the wires
Twist one wire and insert it into tiny hole located in the electric motor
Twist again
Repeat for the other wire

Now you can also use solder to ensure both wires do not touch each other and easily get pulled.

Lastly, ensure the wheels are spinning freely. Do not set the wheel bushing to be too close to the chassis as this is non-precision parts.

Step 4: Done! Mods and Options

You are done!

Now that you have built the kit car, feel free to add options and mod it however you like. For me, first I installed the motor below the chassis so only the solar panel is visible from the top [IMG 2].

Also, I installed sponge / foam tires sourced from my old Tamiya Mini 4WD Racer. If it weren't for that I am sure the tires cost more than the kit car itself. This is important because the plastic tires are too slippery to be used anywhere. Not to mention it kinda looks cool with the colored tires.

I also installed a tiny bi-polar 1F 100WV capacitor. I doubt it is of any use, I just like how it looks on the car. Overall I think this is a fun stuff for the price, but I wouldn't pay more than 5$ for this.