Which load type should I choose?

Center point for symmetric loading, offset for asymmetric, distributed for self-weight, cantilever for overhung loads.

What is acceptable shaft deflection?

General L/3000, gear shafts L/5000, precision L/10000.

Deflection scales as 1/d^4 via I. Doubling diameter reduces deflection 16x.

Use Castigliano theorem, transfer matrix, or FEA for stepped shafts.

First critical speed Ncr = 946/sqrt(delta_mm) RPM (Rayleigh approximation).

Free Engineering Tool #072

Calculate shaft deflection under various loading conditions: center point, offset point, distributed, or cantilever.

Beam Formulas4 Load TypesAuto-Calc

Maximum Deflection

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Max Slope

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Moment of Inertia I

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Max Bending Moment

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Max Bending Stress

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Critical speed: N_cr = 946/√δ_mm RPM. Assumes uniform shaft and simply supported.