Post Deflection Calculator

Calculate lateral deflection, angular tilt, and beam walk-off for an optical post supporting a cantilevered load.

Post & Load
FδLd
Lateral Deflection
Deflection (δ)
δ = ML² / (2EI)
5.036µm
Bending moment
110.3mN·m
Second moment of area (I)
1277.0mm⁴
Angular Tilt
Tilt angle (θ)
θ = δ / L
33.57µrad
6.925arcsec
Beam Walk-off (Double-Pass Reflection)
Angular deviation
2θ for reflected beam
67.15µrad
Spot shift at 500.0 mm
33.57µm
Structural
Bending stress at base
σ = Mr / I
0.5486MPa
Approx. natural frequency
Cantilever with end mass
139.2Hz
Post self-mass
152.0g
Assessment
Moderate deflection — may affect precision alignment. Moderate natural frequency (139.2 Hz).
Abridged Optics — Post Deflection Calculator v1.0Assumes ideal cantilever with rigid base. Real deflection may differ due to post holder compliance.

All information, equations, and calculations have been compiled and verified to the best of our ability. For mission-critical applications, we recommend independent verification of all values. If you find an error, please let us know.