Wowk provides the geometry formulas and graphical vector solutions (using polar graphs) so you can do this with a calculator and paper—no software license required.

The principal inertia axis intersects the geometric axis at the rotor's center of gravity. This requires two correction weights placed 180∘180 raised to the composed with power opposite each other in two different planes.

While the PDF is often sought after for quick reference in the field, the true value lies in Wowk's ability to turn complex into practical, "how-to" steps for real-world machinery.

What are you balancing? (e.g., overhung fan, cooling tower, pump impeller)

Searching for is not just about finding a file. It is about joining a generation of mechanics who understand that balancing is a discipline, not a button-push. Find the document, study the vector plots, and you will never guess where to put a weight again.

This PDF covers the fundamentals of diagnosing machinery vibration, including balancing techniques.