RC Car Upgrade Using 3D Printing
Introduction: RC Car Upgrade Using 3D Printing
RC cars are a fun and inexpensive way to experiment with new and interesting engineering ideas. My name is <PERSON> and as a mechanical engineering graduate student from San Jose State University, I've always loved racecar engineering and wanted to try designing new upgrades for my RC car. The goal for this project is to design 3D printable aerodynamic pieces that upgrade the speed and handling of my Armma Typhon buggy RC car. The concepts designed in this project were inspired by the cars from Formula 1 racing.
Supplies
Hardware
1. Arrma Typhon 1/8 Scale RC car
2. Creality Ender 3 3D printer
3. 3D printer filament (PTEG or ABS preferred for outdoor use)
4. Calipers
5. 2, 3, & 4mm socket head cap screws
6. Blue painters tape
7. Duck tape or Command strips
8. Velcro strap
Software
1. Fusion 360
2. Ansys
3. Matlab
4. Cura
Step 1: Research
To start my project, I first did some research on the basics of car aerodynamics. I read some research papers and watched some YouTube videos to gain a good understanding of how aerodynamics affect a vehicle's performance. I found that front and rear wings give a car a good balance of front and rear downforce, and the shape underneath the car can add downforce via ground effects. Ground effect is the phenomenon where air is forced down into a small space causing a low-pressure region, which creates a vacuum that pulls the car to the floor, also known as downforce. My goal was to apply these same engineering principles to an RC car to see if they can improve the car's performance better than the stock manufacturer's build. 729
I planned to design and build a front and rear wing, an undertray, and side pods that use the ground effect phenomena.
Image Sources: Left image, Right image
Step 2: Measurements
In order to design parts for an existing RC car, it's important to look for and measure any potential mounting locations. I looked for mounting locations that I could screw my parts into so that they would hold securely. I measured the dimensions of the holes to screw the parts into. I found that the front wing could mount to the holes wear the front bumper is mounted, and the new rear wing could mount where the old rear wing was. The side pods could mount to 2 extended tabs with holes on the sides of the chassis, and the undertray could be glued or taped to the bottom of the car.
Step 3: Front and Rear Wing Design
The front and rear wings were designed in Fusion 360 using the NACA 4412 airfoil. The airfoil 2D sketch geometry was obtained from the website Airfoil Tools. A 3-element wing was chosen for the rear wing, and a 2-element wing was chosen for the front. These multi-element wings help gain downforce while lowering drag force. The wings were designed to use center supports that slide the wings through a cutout in the shape of the wing profile. The sides of the wings have holes in which a 2mm and 3mm screw is used to screw the side panels to the sides of the wings. The center supports have holes that use 3mm screws to mount to the body of the RC car. The rear wing mounts to the same holes as the old rear wing, and the front wing mounts to the holes where the front bumper is mounted to.
Step 4: Simulations
Simulations are a great way to test different configurations of aerodynamic pieces. It was important for me to test different front and rear wing setups because I wanted to get good downforce while keeping the drag force as low as possible. I tested about 5 iterations of the front and rear wing using Ansys Fluent CFD software. I found that a 3 element design worked best for the rear wing, and a 2 element design worked for the front. I did not simulate the undertray and side pods because drag is not a major problem for them since the use of ground effect gives low drag, so I skipped simulating those components in order to save time.
Step 5: Undertray Design
The undertray was designed to use ground effect to generate downforce using the floor of the car and the ground. I started by using the spline tool to sketch an inverted wing profile. The undertray profile has a sloping hump and smoothing transition back to flat. This profile squeezes the air against the ground forcing it to move faster under the hump. This fast-moving air creates a low-pressure zone which sucks the car down to the ground. The undertray has fins that run along the length of the undertray. 737