Shaft Critical Speed

Estimate first critical speed from known static deflection at a concentrated rotating mass.

Live concept view — geometry scales with the entered design condition.

Estimate first critical speed from known static deflection at a concentrated rotating mass.

PRELIMINARY RESULT

Estimated first critical speed772 RPM

Formula: Nc = 946 / √δ (δ in mm)

The first critical speed approximation uses the static deflection at the rotating mass location.

FORMULA VERIFICATION

Reference: Shigley, Mechanical Engineering Design, circular-shaft torsion and elementary beam theory.

Internal unit basis: N, mm, MPa and SI rotational units converted explicitly. Outputs: tool-specific SI engineering units.

Valid conditions: Positive finite geometry, load and source-controlled property inputs.

Limitations: Preliminary elastic screening only; no code-compliance, detailed stress concentration or service spectrum design.

Design inputs