What formula is used?

T=4×10^-6 k L^2 f^2 for T in newtons, metre weight k in kg/m, free span L in mm and fundamental frequency f in hertz, as published in the Optibelt V-belt technical manual.

Does the result define the correct installation tension?

No. It estimates the tension corresponding to the measured span frequency. The required target must come from the exact belt product and drive design.

Why was the deflection-force method removed?

A manufacturer force-deflection procedure compares force at a specified deflection with product-specific data. The former ideal-string equation did not account for belt axial and bending stiffness and could not generally infer installed static tension.

Which frequency should be entered?

Use the measured fundamental transverse frequency of the specified free unloaded span under the instrument and product procedure, not an arbitrary spectral peak.

Can the same generic limits be used for every belt?

No. Target frequency or tension depends on belt product, width or belt count, span, drive geometry, power and installation state.

Strumento di ingegneria gratuito

Belt Span Frequency Tension Estimator

Estimate static span tension from the measured fundamental frequency, free span length and manufacturer belt metre weight.

Optibelt Frequency RelationUnit-SafeNo Universal Target

Estimated Span Tension

Static span tension T

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Reference force unit

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Normalized metre weight

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Normalized span

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Frequency relation

T = 4 × 10⁻⁶ × k × L² × f²

T — static belt span tension (N)
k — metre weight of the exact belt (kg/m)
L — free oscillating span length (mm)
f — measured fundamental frequency (Hz)

The relation is equivalent to the ideal stretched-string fundamental f=(1/(2L))√(T/k), with the unit factor for L in millimetres. Real belt stiffness and measurement conditions can create small deviations; use the manufacturer procedure and actual metre weight.

Published verification example

Optibelt gives k=0.377 kg/m, L=2189.3 mm and f=14.33 Hz, producing T=1484.24 N (approximately 1484 N).

Fonte: Optibelt Technical Manual V-Belt Drives, frequency meter/tension tester section.

Not a target selector: obtain required first-install and re-tension values from the exact belt and drive calculation. Do not apply generic ranges, universal new-belt multipliers or maintenance intervals.