Introduction
Problem (in 1 line): Most “belt failures” are installation failures—wrong tension and misalignment drive tooth wear, ratcheting, and flange burn.
Target (what good looks like): Pretension set with a sonic tension meter; no ratcheting at peak load; parallel offset ≤ 0.5 mm per 100 mm span; angular misalignment ≤ 0.25° (~0.44 mm over 100 mm); ≥ 6 teeth engaged on the small pulley; full-width contact—no edge polish or flange rub.