⏲️ Dial Indicator: Rack-and-Pinion Gearing, Runout, Cosine Error and Backlash (2D)

Front view of a 0.01 mm dial indicator reading the runout of a turning shaft. Set the eccentricity, probe tilt, gear backlash, spring preload and rate, and watch the pointer follow the plunger. The train ratio, the cosine under-reading, the spring work and the backlash error are computed, with four in-page numerical checks. A measurement companion to the 3D dial gauge.