Power Electronics, Motors & Drives worked example

Rotor Balancing Cost at 92% share of rotors requiring balancing: a worked example

Push share of rotors requiring balancing up to 92% and the picture changes. This example computes every intermediate figure at that operating point. Use it when quoting or planning dynamic balancing for motor rotors, high-speed shafts, traction motor rotors, or repaired rotating assemblies.

The inputs for this scenario

  • Rotors in scope: 100 rotors (unchanged)
  • Balancing cost per rotor: 45 $ / rotor (unchanged)
  • Share of rotors requiring balancing: 92 % (raised for this scenario; the documented default is 80)
  • Fixed balancing setup cost: 250 $ (unchanged)

Working through the calculation

  • Applying the documented formula (Variable rotor balancing cost = rotors in scope × balancing cost per rotor × rotors requiring balancing) to the inputs above produces each figure below.
  • At this operating point the engine returns 4,390 $ for total rotor balancing cost, the number this scenario is built around.
  • At this operating point the engine returns 43.9 $ / piece for rotor balancing cost per rotor.
  • At this operating point the engine returns 4,140 $ for variable rotor balancing cost.
  • At this operating point the engine returns 250 $ for fixed balancing setup cost.

How this compares with the baseline

  • Against the tool's baseline example, where share of rotors requiring balancing sits at 80% and the headline result is 3,850 $, this scenario comes in 14.03% above the baseline at 4,390 $.
  • It computes total rotor balancing cost from variable per-rotor cost weighted by the share needing balancing plus a fixed setup, and derives a blended per-rotor figure. The value of this scenario is the size of the gap it exposes: that gap, priced out over a year, is the budget you can justify spending to close it.

Results at a glance

  • Total rotor balancing cost: 4,390 $ (headline result)
  • Rotor balancing cost per rotor: 43.9 $ / piece
  • Variable rotor balancing cost: 4,140 $
  • Fixed balancing setup cost: 250 $

Run it with your numbers

  • Every input above is editable in the live Rotor Balancing Cost calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.