Balancing Machines:

You have been exposed to the calculation of disturbing forces that arise because of unbalanced system of forces in machines & machine parts. The possible recommendation for design has also been obtainable for complete or partial balancing.

The designer is likely to take all of the  measures in making rotating parts of machines completely balanced so that out-of-balance force or moment are removed, however either because of slight variation in material density or inaccuracies in casting and machining residual errors might exist. Such residual out-of-balance force and couple need to be determined for deciding and executing practical measures for achieving 100% balanced system. For this balancing machines are required. The requirement for determining definite state of machine part (whether static or dynamic) may not be overlooked even if such imbalances are small. We have to remember that the centrifugal forces and moments because of these forces are proportional to square of angular speed and therefore small increase of angular speed might result in considerable enhance in unbalanced forces and moments even if the inaccuracy in machine part is extremely little.

In such cases where a rotating part is of big diameter and comparatively narrow width the static balancing might be sufficient. In such cases dynamic couples shall be so small that their influence might not cause much disturbance. But, for parts that are long axially, dynamic balancing might be necessary. The need of balancing has translated into existence of various balancing machines of static and dynamic kinds to help resolute the balanced state of rotating parts. There are machines that can measure static and dynamic both unbalance.