Interactive tool. Converts a rigid rotor’s unbalance between the per-plane form a balancing machine reports (UA, UB) and the equivalent static-and-couple form (Ueq, Ceq), with magnitude and phase in both directions. SI and US units, with a printable record.
This calculator converts a rigid rotor's unbalance between the per-plane form a balancing machine reports (UA, UB) and the equivalent static-and-couple form (Ueq, Ceq), in either direction. Enter the plane separation and either pair of vectors as magnitude and phase; it returns the other pair and classifies the unbalance as static, couple, quasi-static, or dynamic, in SI or US units, with an explanation in prose of what each result means and a printable record. Companion tool to Two-Plane Balancing: The Fundamentals. Part of the balancing series.
The calculator's results have been compared with those of a separately written program in 6,000 randomized cases, and every displayed value agreed with it to the last digit. Further tests confirmed that converting to the static-and-couple form and back returns the original plane vectors, and that rotating or scaling the inputs rotates or scales the results alike. The calculator also reproduced the results of two worked examples from a reference text.
Sample output
The calculator's output for its first example, Dynamic unbalance: plane A 800 g·mm at 30° and plane B 600 g·mm at 255°, with the planes 500 mm apart, converted with the equations of the Static-and-Couple Form section of Two-Plane Balancing: The Fundamentals.
Result
Static & couple
Static unbalance Ueq magnitude (g·mm)
566.7
Static unbalance Ueq phase (°)
341.5
Couple unbalance Ceq magnitude (g·mm²)
323,923
Couple unbalance Ceq phase (°)
49.11
Unbalance type
Dynamic
The printed record of the same example. Click the image to enlarge it.
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