For engineers who already know the math—but still lose projects. For the last few years, I’ve been sharing technical guides here on Mechanical Design Handbook —how to size a motor, how to calculate fits, and (as you recently read) how to choose between timing belts and ball screws. But after 25 years in industrial automation, I realized something uncomfortable: Projects rarely fail because the math was wrong. They fail because: The client changed the scope three times in one week. A critical vendor lied about a shipping date (and no one verified it). The installation technician couldn’t fit a wrench into the gap we designed. University taught us the physics. It didn’t teach us the reality. That gap is why I wrote my new book, The Sheet Mechanic . This is not a textbook. It is a field manual for the messy, political, and chaotic space between the CAD model and the factory floor. It captures the systems I’ve used to survive industrial projec...
Key Geometric Calculations In Part 2 , we analyzed the loads. Now, we must size the geometry. Designing a chain drive involves a specific sequence: determining the sprocket size, estimating the center distance, calculating the required chain length in "pitches," and then recalculating the exact center distance. Search for "Machine Elements in Mechanical Design" Advertisement 1. Pitch Diameter The pitch diameter is the theoretical circle that passes through the centers of the chain pins. D1 = Pitch Diameter of Driver Sprocket (Small) D2 = Pitch Diameter of Driven Sprocket (Large) N1 = Number of Teeth on Driver N2 = Number of Teeth on Driven p = Chain Pitch D 1 = p sin( 180 / N 1 ) Calculator Note: Most calculators default to Degrees mode. If using Degrees : Use 180 / N If using Radians (e.g., Excel): Change 180 to Ï€ → sin(Ï€ / N) ...