What is a common pitfall when designing a mechanism?

• A. Using only off-the-shelf components.
• B. Over-engineering complexity that hurts reliability and maintainability.
• C. Underestimating the power of modularity.
• D. Focusing solely on appearance.

Answer: (B)

When designing a mechanism, the most common trap is adding more complexity than is needed. Over-engineering looks tempting because it promises greater capability, but it often backfires by making the mechanism less reliable and harder to maintain. Each extra part, joint, gear, or sensor introduces another potential failure point, more alignment requirements, and additional wear paths. It also increases manufacturing and assembly costs, makes troubleshooting tougher, and reduces robustness to real-world conditions like dirt, temperature changes, or component wear. A simpler, well-justified design tends to perform more reliably, be easier to assemble, and easier to service over its life.

Relying on off-the-shelf components isn’t inherently wrong and can be efficient if they meet the needs; underestimating modularity or focusing only on appearance miss the practical balance between function and maintainability, but they aren’t the classic pitfall in the same way.