How to Build Your Own Remote-Controlled Hummer

This week, I want to share a project made by a 14-year-old student who participated in an AI challenge, using the help of ChatGPT to create a remote-controlled car project, including the author’s journey.

Materials Needed

• Fly Sky controller/receiver (any controller will do)
• Arduino Nano (you can also buy other cheaper development boards based on ATmega328)
• L298N motor driver
• Battery pack (the author used a battery from another remote-controlled car) Update: Due to the small motor, a 9V battery should be sufficient. (I haven’t tested this yet) (just ensure there is a battery connector)
• DC motor set
• Micro servo
• Female T-shaped connector
• Female to female connecting wire
• 3mm LED/resistor (optional)
• M3 screw pack
• Drill + hex wrench
• 3D printer
• PLA
• TPU (optional)

3D printing files can be found here:https://makerworld.com/zh/models/250674?from=search#profileId-266940

Step 1: The Challenge with ChatGPT

To start this challenge, I opened ChatGPT and input some parameters.

I told it to give me a project challenge that includes electronics, 3D printing, is budget-friendly, and has a moderate level of difficulty.

I didn’t want it to be too simple or too difficult, but something that could challenge my brain while still being achievable.

You can check the images to see what I input in ChatGPT and the result – to make a functioning remote-controlled car!

To control the budget, I decided not to use brushless motors and large batteries. I also planned to use my own components as much as possible, only buying when absolutely necessary.

I also had a personal goal – to make this project completely independent and unique.

One of the challenges ChatGPT gave me was to use a servo for steering.

If I didn’t use a servo, I could use four-wheel drive with two motor drivers for tracked movement. I was glad it was more complex because I could learn more new things, while four-wheel drive is very simple and wouldn’t challenge me at all.

I did a lot of research (like learning how to create a steering system) and then started tinkering!

Step 2: Modeling

First, I wanted to start this project by determining the size of the remote-controlled car.

I wanted it to be small, but as I started assembling the parts, I realized it needed to be a bit larger to accommodate all the components.

I designed the chassis in Fusion 360 and went through many designs that needed to accommodate the Arduino and different battery boxes.

I learned that one must remain flexible during this process and not feel frustrated when something doesn’t work. I spent many hours designing, 3D printing prototypes, finding problems, and repeating the process, but each time I learned something new.

The most challenging part of the chassis was the steering mechanism.

I spent a lot of time researching how steering works and how to apply it to my small remote-controlled car. Similarly, I went through a lot of trial and error until I finally achieved a workable design.

Finally, I needed a body. I wanted it to look cool and ultimately chose a Hummer! I used photos and imported them into Fusion 360 to get a good shape, then added details like lights, doors, and antenna holes.

Step 3: Coding

Now it’s time to write code! I had a basic understanding of Arduino coding, but now I had to learn how to put the coding into practice using the remote control.

I had a FlySky controller and needed to learn how to code PWM/IBUS and get it to work with the Arduino Nano.

I first tried reading PWM but couldn’t get it to work. I was able to read it, but the signal changed even when I didn’t move the controller.

Then I learned about IBUS and started referencing some example codes just to see how IBUS worked. After learning how to read the signals, I integrated it into my design.

I wrote some code to read the channels and then wrote the channel values into Excel. These values had high, medium, and low states. (So one switch on the controller is (2000, —–, 1000), and the joystick (CH1) is (2000, PWM, 1000)). Then, I used Excel to control the motor via the controller.

After a very long time, I finally wrote some code. I tried many times, and some of the issues were slight deviations in the limits, which caused the code to get messy and the motor to not move. Later, I solved this problem by adding constraints to the variables. Of course, there were other issues, but they were all quite simple.

The complete code can be viewed in the assembly steps.

Step 4: Testing and Troubleshooting

During the testing phase, I encountered many problems, hard to imagine what a real automotive company would go through!

Here are some major issues:

(Issue – Cause)

• Slow movement – motors were too cheap
• Couldn’t drive on any rough surface – motors were too cheap + wheels were too small
• Battery drained quickly – 9V battery couldn’t handle the current
• The steering system worked fine, but took up a lot of space on the chassis
• The chassis was messy (wires and modules stacked together) – trying to keep it as simple and compact as possible

Step 5: Problem Solving

Next, I set out to solve these problems!

I researched more steering methods to achieve a higher spatial efficiency while still maintaining functionality. Ultimately, I chose Ackermann steering.

To solve the motor power and slow movement issues, I bought some stronger motors and designed larger tires using Fusion 360 for 3D printing, providing better traction, using TPU for 3D printing, so they were both sturdy and had some flexibility. (You don’t necessarily need to use TPU for printing, but I recommend it if you have it)

To organize the chassis, I designed baffles to help plan the component locations. I used screws to secure the Nano board and L298N motor driver.

To solve the battery issue, I replaced the two 9V batteries with a rechargeable lithium-ion battery for remote-controlled cars, which has a higher energy storage capacity. Now it can run longer and provide more current!

Step 6: Final Results

I succeeded! Created a functioning remote-controlled car from scratch!

Although it looks a bit messy inside due to the wires tangled at the top, if you move them aside, you’ll find everything is still compact and orderly.

I later decided to add a silicone spray to apply to the wheels for better grip.

Below are two test videos.

▼ Driving on Cement Road

▼ Off-Roading

Step 7: How to Assemble It Yourself

I didn’t write the steps in detail in the article, you can refer to the video for more information.

▼ Assembly Video

Some tools you will need:

• Electric screwdriver

You definitely need an electric screwdriver to screw in all the screws. Most models are assembled by screwing into the 3D printed parts. (Otherwise, your wrist will get tired)

• Glue: hot glue, super glue, etc. (any glue that can secure the motor to the chassis)

Notes

• You can glue the tires onto the motors, but I don’t recommend it because the tires may break, leading to having to disassemble the tires and potentially damaging the motors. Also, you may need to replace old tires with new ones in the future.

• Make sure the servo motor wires pass through the holes for a neater appearance.

• Finally, do not drill the screws too deep into the 3D printed parts, as this may damage the threads. It is advisable to drill slowly and stop once you feel the drill bit starting to feedback.

The above image is a wiring diagram, which you can refer to along with the video. The related code can be downloaded at the end of the article.

Step 8: Conclusion

This was a challenge I was almost reluctant to accept, but I’m glad I did.

I created a very interesting remote-controlled car and learned a lot in the process.

Many lessons I’ve learned:

• Code/Reading IBUS
• Steering
• Modeling complex joints
• Motor selection/load = more current

I learned to step out of my comfort zone, learn more coding and steering knowledge, and ended up with a truly functioning remote-controlled car! Overall, I am very satisfied with the results of this project, and I am happy to have accepted this challenge!

Step 9: Next Steps

Now that the car is complete, my mind is racing with various ways to modify it. I’ve started researching how to integrate a camera into the body, different types of tires (maybe drifting!), and different body styles. I admit that I will never be satisfied; once I have more money, I might buy brushless motors to truly upgrade it!

Finally, I want to see what everyone will create. I have provided an editable model that you can change freely.

Maybe an upgrade to the chassis, a new shell, or even more features like a camera, tracked drive; let your imagination run wild and give it a try!

Click to learn more👆

DFRobot Official Brand Store https://dfrobot.taobao.com/

DFRobot Official Flagship Store https://dfrobot.jd.com/

Files mentioned in the article, can click the lower left cornerRead the original text, or reply “Remote-Controlled Hummer” in the public account to get it!

If you have anything to say, feel free toleave a message!

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