Belt Passing Frequency Calculator
Belt frequency and its harmonics from pulley diameter, speed and belt length — for hunting belt-driven spindle vibration.
Belt frequency sits BELOW shaft speed — the giveaway that separates a lumpy belt from unbalance in a spectrum. A glued splice or hard spot shows at 1× and 2× belt frequency and often disappears for a day after re-tensioning, then returns.
Formula
Note: Condition-monitoring guidance, not a substitute for the machine maker's limits or a qualified vibration analyst on safety-critical equipment.
Belt frequency and its harmonics from pulley diameter, speed and belt length — for hunting belt-driven spindle vibration. A free cnc machining: speeds, feeds & tool wear tool — no sign-up, no upload, instant results in your browser.
About Belt Passing Frequency Calculator
Belt Passing Frequency Calculator computes the governing relationship f_belt = π·D·n / (60·L) live as you type. Belt frequency sits BELOW shaft speed — the giveaway that separates a lumpy belt from unbalance in a spectrum. A glued splice or hard spot shows at 1× and 2× belt frequency and often disappears for a day after re-tensioning, then returns. Defaults are pre-filled with realistic values for this exact scenario, and the worked example substitutes your numbers step by step so the math is never a black box.
How to use Belt Passing Frequency Calculator
- 1Enter your values — Driver pulley speed, Driver pulley pitch diameter, Belt pitch length (sensible defaults are pre-filled).
- 2Read the live results: Belt passing frequency, 2× belt frequency, Belt speed.
- 3Check the "with your numbers" line to see f_belt = π·D·n / (60·L) substituted step by step.
- 4Adjust inputs until the scenario matches yours, then copy or share the result.
Why use Belt Passing Frequency Calculator?
- ✓Instant, free and private — every calculation runs client-side in your browser; nothing is uploaded
- ✓Built on the stated formula f_belt = π·D·n / (60·L) with authoritative sources cited on the page (ISO 20816-1 (ex 10816) — Mechanical vibration evaluation; ISO 21940-11 — Rotor balancing; ISO 3685 — Tool-life testing with single-point turning tools)
- ✓Belt frequency sits BELOW shaft speed — the giveaway that separates a lumpy belt from unbalance in a spectrum.
- ✓SI ⇄ Imperial toggle converts your inputs in place, so you can work in the units your drawings use
Frequently asked questions
What formula does the belt passing frequency calculator use?+
It evaluates f_belt = π·D·n / (60·L), exactly as published. Sources: ISO 20816-1 (ex 10816) — Mechanical vibration evaluation; ISO 21940-11 — Rotor balancing; ISO 3685 — Tool-life testing with single-point turning tools. The substituted worked example on the page lets you verify every step against the textbook.
How should I read the result — and how far can I trust it?+
Belt frequency sits BELOW shaft speed — the giveaway that separates a lumpy belt from unbalance in a spectrum. Condition-monitoring guidance, not a substitute for the machine maker's limits or a qualified vibration analyst on safety-critical equipment.
When is this calculator the right tool for the job?+
Belt frequency and its harmonics from pulley diameter, speed and belt length. A glued splice or hard spot shows at 1× and 2× belt frequency and often disappears for a day after re-tensioning, then returns. For neighbouring scenarios, the related tools below cover the same engine with different presets.
Does it support both metric and imperial units?+
Yes — the SI ⇄ Imperial toggle converts the values already in the fields, preserving the physical quantity, so you can flip mid-calculation without re-entering anything.
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