Olin Baja 2024-26 - Pranav Bonthu

Steering Wheel Telemetry PCB (2026)

I designed a custom PCB in KiCad that mounts in the car's steering wheel. It shows live data from the telemetry system on a screen in front of the driver and adds a voice radio link between the driver and the pit crew.

Hardware:

STM32F446 microcontroller with a built-in CAN bus for talking to the rest of the car
2.8" ILI9341 TFT display over SPI (footprint made from scratch)
DRA818V VHF transceiver for driver-to-pit voice communication
Onboard microphone and speaker so the driver can talk to and hear the pit

Telemetry:

GPS and IMU tracking systems for real-time data collection
Live data displayed to the driver during runs
Logged data used to tune vehicle performance

Dog Clutch Assembly

I designed a complete chain drive system for our Baja vehicle, incorporating both power transmission calculations and a unique 4-wheel drive engagement mechanism. This system allows seamless switching between 2-wheel drive and 4-wheel drive modes during operation.

Dog Clutch

The dog clutch is the core component of our 4WD engagement system. It was designed to rotate on the front spool of the car and, when needed, be pushed in while rotating to seamlessly fit into the sprocket. Once the teeth engage with the sprocket, the car operates in 4-wheel drive mode. The reverse process disengages the system, returning the car to 2-wheel drive.

Key Features:

Designed to rotate on the front spool
Seamless engagement while rotating
Instant 4WD/2WD switching capability
Precision-machined teeth for reliable engagement

Dog Clutch Side View

3D rendering showing detailed mechanical structure

Angled View

Complete system view with engagement mechanism

Sprocket

The sprocket component was determined through detailed MATLAB calculations to optimize our chain drive system. This component interfaces with the dog clutch to provide reliable power transmission when engaged. The sprocket design ensures optimal chain engagement and efficient power transfer to the front wheels.

Design Specifications:

Optimized through MATLAB calculations
Designed for seamless dog clutch engagement
Custom tooth profile for optimal chain performance
High-strength alloy steel construction

Sprocket

Chain drive interface component

Fork System

The fork system I designed controls the engagement and disengagement of the dog clutch. This fork attaches directly to the dog clutch and uses spring-loaded mechanisms for precise control. When the springs are contracted, the dog clutch separates from the sprocket, disengaging 4WD. When the springs are released, the fork moves the dog clutch into the sprocket, engaging 4WD mode.

Mechanical Properties:

Spring-loaded engagement mechanism
Direct attachment to dog clutch
Precise control of engagement/disengagement
Reliable operation under dynamic conditions

Fork System Design

Spring-loaded engagement mechanism

Fork System Assembly

Complete engagement control system

System Operation:

Spring compression disengages 4WD mode
Spring release engages 4WD mode
Direct mechanical control of dog clutch
Reliable operation under dynamic loads

The fork system provides precise control over the dog clutch engagement, ensuring smooth transitions between 2WD and 4WD modes during vehicle operation.

Chain/Sprocket Calculations

I performed detailed calculations using MATLAB to determine the optimal combination of sprocket and chain for our chain drive system. These calculations were essential for ensuring proper power transmission efficiency and selecting the right components for our Baja vehicle's performance requirements.

MATLAB Analysis:

Gear ratio optimization for terrain conditions
Chain tension calculations for various loads
Power transmission efficiency analysis
Component sizing and selection
Performance validation under dynamic conditions

These calculations formed the foundation for selecting the optimal sprocket size and chain specifications, ensuring reliable power transfer from the engine to the wheels while maintaining efficiency across different operating conditions.

MATLAB Calculations

Screenshot of MATLAB analysis for chain/sprocket optimization

Analysis Results

Detailed MATLAB output showing calculation results

Key Findings:

Optimal sprocket ratio determined for maximum efficiency
Chain specifications validated for load requirements
Power transmission losses minimized
Component durability verified under stress conditions

The MATLAB analysis provided critical insights into the performance characteristics of different sprocket and chain combinations, enabling informed design decisions for our drivetrain system.

Chain Tensioning

Proper chain tensioning is crucial for maintaining power transmission efficiency and preventing premature wear. Our system incorporates automatic tensioning mechanisms that adapt to varying operating conditions.

Tensioning System Features:

Automatic tension adjustment during operation
Spring-loaded tensioner for consistent pressure
Wear compensation mechanisms
Easy maintenance access for adjustments
Durable tensioner materials for longevity

The tensioning system automatically compensates for chain stretch and wear, maintaining optimal performance throughout the vehicle's operating life.