Final Project - Tennis Ball Collector

Project Overview

Final Presentation

Final Video Presentation

The project consists of developing a tennis ball collecting machine, designed to automate a process that is currently performed manually in clubs and sports academies. By integrating a traction system like "Car Track" powered by Artificial Intelligence, the device identifies, chases and collects balls autonomously. This makes it possible to optimize training time, reduce the physical effort of staff and improve operational efficiency within sports facilities.

About the Company

REMSTEC www.remstec.com is a company dedicated to the development of cutting-edge technology, specializing in embedded products powered by Artificial Intelligence. Their job is to integrate advanced processing capabilities directly into the hardware for real-time decision making. In addition, they focus on the training of technical talent through PLC and advanced systems trainings, always maintaining the pride of producing disruptive technology designed and materialized entirely by their own engineering.

The Problem to Solve

In tennis, success is directly linked to the repetition frequency of strokes and the intensity of training. However, handpicking balls acts as a logistical bottleneck.

35% - 40% of training time spent exclusively collecting balls.

20 - 24 min net loss per hour of a standard session.

80 hours wasted per year by a high-performance athlete.

Technical & Physical Impact

Declines in Muscle Memory: The development of elite technique requires a high volume of controlled impacts. By losing 40% of the time, a player performs approximately 150 to 200 reps less per session than an automated court would allow.
Physical wear and tear of the technical staff: The technical staff performs hundreds of lumbar flexions daily to empty baskets and collect balls from the ground. This repetitive effort generates accumulated fatigue, postural problems (chronic lumbalgia) and reduces the energy that the coach should channel to correct the technique.

The Psychological Toll: Breaking the 'Flow State'

In sports psychology, the Flow State is the zone of maximum concentration where the athlete performs movements semi-unconsciously and optimally.

Each time the training stops abruptly for 3 or 5 minutes to "clean the court", the player’s heart rate drops dramatically and their mental focus is broken.
Restarting the session requires a new period of readjustment and warm-up, preventing the athlete from maintaining the intensity needed to simulate real match situations.

Design & Planning

The system was designed using a modular approach. Using Fusion 360 for mechanical design and KiCad for the custom PCB control system.

For the first stage of prototyping, 18 mm thick wood was selected. Using the CNC milling machine, machining of the outer contour and drilling of the bores for the side parts of the project was carried out.

For the chain system, a custom design manufactured by 3D printing was chosen due to the accessibility of the process and cost optimization. In order to ensure the necessary mechanical strength, a filling density (infill) of 100% was set up

For the 5-inch rim fastening system, M16 screws were designed and manufactured using 3D printing. This technology was selected for its low cost and the accessibility of the process, also allowing to customize the length and diameter required for assembly.

In the image is shown the first prototype of the lateral parts of the ball-picking mechanism. After the operating tests, it was identified the need to modify the original design, since the oversize of the part raised the system excessively, compromising the optimal height of operation.

For the ramp, I decided to use foamed PVC. With the help of a heat gun, I applied temperature to the material to give it the curved shape manually and adapt it to the mechanism.

For the rear section of the system, a structural support was designed that fulfills the function of joining the side faces and housing the rotating slats (type supermarket rim), thus allowing free pivoting and maneuverability of the assembly.

In the image you can see the finished back piece. This has the necessary baffles for mounting the rotating slats and a housing for a bearing, the purpose of which is to attach a secondary axis that allows the free pivoting of the system.2

To make the part that pushes the balls, I combined white foamed PVC with an aluminum element. At the center of this assembly, a welded shaft was secured to ensure that the part could rotate freely

In the image, the lateral parts that make up the ball collector are observed along with its wheels. Also shown is the rear part, which has the supermarket wheels screwed on, and the ramp that allows the balls to climb

Final render of the robot

Mechanical Prototyping

3D printing and laser cutting processes for chassis and mechanical components development.

First scale prototype manufactured by 3D printing, developed for the purpose of validating mechanical viability, system operation and accuracy of geometric dimensions.

Machining and cutting of the side parts using the CNC milling machine, controlled through the software Mach3

Sprocket design and manufacturing process using 3D printing technology to obtain the functional component.

Laser cutting of MDF chassis

First prototype assembly

Electronics & PCB Design

Custom PCB design using KiCad, component soldering, and system integration testing.

Milled PCB board

Component soldering process

PCB Schematic in KiCad

Milled PCB board

Electronics testing and validation

Components Used

4 Motor drivers
4 Motors
2 PCBs custom-made in collaboration with the company
Battery
Fuse box

Implementation Timeline

Week 1-4: Prototyping

Testing the collection mechanism and initial chassis assembly using 3D printed parts.

Week 5-8: Electronics

Integration of Raspberry Pi Pico and motor drivers. Development of the AI vision script.

Week 9-12: Final Assembly

Final CNC cutting of the chassis and full-system testing in the field.

Resources & Materials

MATERIAL	QUANTITY	UNIT COST (MXN)	TOTAL COST (MXN)
18 mm Plywood Sheet (4x8 ft)	1	750	750
PLA 3D Printer Filament Spool (1 kg)	1	350	350
Expanded PVC Sheet (Sintra)	1	400	400
Lawn Mower Type Wheels	2	180	360
M8 Bolts with Nuts and Washers	8	12	96
1/2-inch Bolt with 2 Nuts and 2 Washers	1	25	25
Expansion Anchor Bolts (Pijas de expansión)	4	15	60
15 mm Pillow Block Bearings with mounting bolts (Chumaceras)	2	130	260
Bicycle Chain	1	140	140
Bicycle Chainring (Plato)	1	180	180
Set Screw (Prisionero)	1	15	15

Final Assembly & Testing

Complete integration of all systems and field testing results.

Fully assembled robot

Field testing on tennis court

AI vision system tracking balls

Final demonstration - Autonomous ball collection