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...
The German engineer Otto Mohr (1835-1918) developed a useful pictorial interpretation of the equations for finding principal stresses and maximum shearing stress at a point in a stressed member. Advertisement This method, commonly called Mohr's Circle , involves constructing a circle where the coordinates of each point represent the normal and shearing stresses on a specific plane. The angular position of the radius gives the orientation of that plane. Understanding the Plot Figure 1: The geometric relationship between Normal Stress (σ) and Shear Stress (τ). Coordinate Rules: Normal Stresses (σ): Plotted on the horizontal axis. Tensile (+) is right; Compressive (-) is left. Shearing Stresses (τ): Plotted on the vertical axis. Clockwise rotation is above the axis; Counter-clockwise is below. The results obtained from Mohr's circle are identical to the equations derived from the free-body diagram. ...