Interactive tool. Solves a complete at-speed or trim balancing job: up to five planes, plane sets for modal balancing, twelve probes, and six speeds, with influence coefficients fitted from every run, least-squares corrections weighted by acceptance limits, and a printable report.
This calculator solves a complete at-speed (high-speed) balancing job, from the baseline and trial runs through the corrections and the trim corrections that follow them: up to five correction planes, up to twelve probes, and up to six speeds, with a chronological run log. Enter each run’s mass changes and readings, and it fits the influence coefficients from every run, reports each reading against its acceptance limit, recommends the next correction in each plane by least squares, and predicts the residual, with an explanation in prose of what each result means. Plane sets let it handle modal balancing, alone or combined with plane-by-plane trials, and it sizes the recommended trial masses for every plane and set — with run-history polar plots, save and reload, and a printable report, in SI or US units. Companion tool to At-Speed Balancing: Machines and Procedure. Part of the balancing series.
The calculator's results have been compared with those of a separately written program in 16,000 randomized jobs, and every result agreed with it to within the round-off of the arithmetic. In a simulated balance of a flexible rotor at two speeds, on an independently written rotor model, its corrections brought the largest reading from 111 % of its limit to 0.7 %. The calculator also reproduced the results of four worked examples from a reference text.
Sample output
The calculator's output for the worked example in the Plane-by-Plane Influence Coefficient Method section of At-Speed Balancing: Machines and Procedure: one correction plane with a 250 mm radius and one probe at 9,000 RPM, with an acceptance limit of 25 µm pk-pk; a baseline reading of 40 µm pk-pk at 120°; and an 8 g trial mass at 0° that changes the reading to 62 µm pk-pk at 150°.
Plane A on r = 250 mm
Unbalance to add
Mass to add
Or mass to remove
Additional to what is on the rotor
3,659 g·mm at 143.8°
14.6 g at 143.8°
14.6 g at 323.8°
Net relative to the baseline state
2,361 g·mm at 113.8°
9.44 g at 113.8°
9.44 g at 293.8°
The response history and the printed record for the same example. Click either image to enlarge it.
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