Toolholder and tool balance

Machine users often hear that they need to balance their tool holders are discussed. The rotating components in a machine tool spindle are many. There may be the rotor of an electric motor or gears or pulleys if the motor is not integral with the spindle. The net effect is the same as if there is a mass attached off center on the spindle. The size of the unbalanced mass and its distance from the center of rotation play the same role, and those terms usually are grouped together. a more important consideration is whether the force produced by the rotating unbalance is an appreciable fraction of the force produced by the cutting operation. Reducing those forces through balancing is beneficial, but balancing also comes with costs. A good strategy for deciding about whether or not to balance is to compare the unbalance force to the cutting force.