Project Overview
This project focused on resolving a critical issue encountered during bot-level motor validation testing using flywheel-based load simulation. The testing method required mounting flywheels directly onto the robot shaft to replicate inertial loading conditions experienced in operation. However, the shaft was supported by press-fit bearings that were not designed to withstand axial or impact loads.
During repeated test cycles, the act of placing the flywheel onto the shaft introduced significant dynamic impact forces, which risked loosening the bearings or shifting their position. This created a failure mode where the test setup itself could damage the system under test, compromising both hardware integrity and the validity of test results.
Analysis & Design Approach
I approached the problem by analyzing the loading condition from both a force-based and energy-based perspective, estimating the transient impact loads generated during flywheel placement. These calculations were validated experimentally, confirming that the peak loads exceeded safe limits for the bearing interfaces.
To address this, I designed a spring-damper mechanism integrated into the flywheel hub to absorb and redistribute the impact energy. The system consisted of a compressive spring element, a central guide (clevis pin) to maintain alignment, and a load-transferring interface that ensured consistent contact with the shaft. This allowed the initial energy transfer to occur over a controlled displacement, significantly reducing peak force transmission while maintaining system stiffness during steady-state operation.
A key aspect of the design was ensuring robustness in real-world use. The system was intentionally designed to be foolproof for technicians, preventing improper loading scenarios such as dropping the full flywheel mass directly onto the shaft, and ensuring consistent test conditions across repeated cycles.
Results and Takeaways
The design was prototyped and validated through repeated testing, demonstrating a significant reduction in dynamic loading and eliminating observed bearing displacement and alignment issues. The system preserved the accuracy of the test while improving reliability and repeatability of the validation process.
By addressing the unintended consequences of the test method, this solution ensured that system performance was evaluated under controlled conditions, rather than being influenced by test-induced artifacts. The project highlighted the importance of designing not only the system under test, but also the test infrastructure itself, with equal attention to failure modes, user interaction, and real-world conditions.
Key Takeaways
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Dynamic loading must be evaluated using both force and energy methods
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Test setups can introduce critical failure modes if not properly engineered
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Simple mechanical solutions can effectively mitigate high-impact transient events
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Designing for user behavior and misuse prevention is essential for reliable systems