Technical Information Balancing Balancing The permissible residual unbalance can be calculated by the following equation: F = U x (n/9,549)2 (Newtons) Where: U = unbalance in gram millimeters (gmm) N = rotational speed (RPM) In this particular case, the unbalanced induced force would be Good balancing quality does not necessarily guarantee safe operation at higher F = 1 x (25,000/9,549)2 = 6,9 N. The cutting forces generated speeds. Other variables (spindle connection, type of operation, cutting parameters, are likely to be orders of magnitude greater than that. machine stiffness, bearing condition, etc.) should always be considered. Unbalance can be corrected by material removal (drilling, milling, grinding), material For a given unbalance, the following formula can be used to determine the hole addition (set screws), and material redistribution (balancing rings or set screws). depth (L) necessary to correct for the unbalance*: * Formula for steel components only. L= D- D2 - U x 1300/d2 2 Where: U = unbalance (gmm) D = diameter of placement (mm) d = hole diameter (flat bottom) (mm) L = hole depth (mm) WWW.WIDIA.COM K55 Technical Information