DatumNest: Tolerance Stack

DatumNest is a mechanical tolerance-stack laboratory for product engineers, machinists, quality teams, manufacturing students, and design-review conversations. Build a signed one-dimensional chain with explicit nominal values, bilateral tolerances, sensitivity coefficients, notes, and distribution assumptions. DatumNest calculates nominal closure, worst-case range, RSS standard deviation, variance contribution, and a deterministic 12,000-run Monte Carlo yield screen against entered limits. KEY FEATURES - Signed dimension-chain workspace - Worst-case min and max closure - RSS standard-deviation estimate - Rectangular, triangular, and normal ±3σ assumptions - Variance contribution ranking - Seeded 12,000-run Monte Carlo distribution - Editable specification limits - Local engineering PDF report - 300 original offline technical plates - No account, ads, analytics, tracking, IAP, or subscription DatumNest is an engineering screening and communication tool. Confirm datum schemes, geometric effects, correlations, distribution assumptions, process capability, units, and acceptance criteria with qualified design and quality personnel.