Between tips
“Between points” is a term from manufacturing and measurement technology and describes a certain way in which a workpiece or test item is clamped on a machine or device. The term is usually called together with the method which undergoes the clamped body, for example between the tips of rotating , between the tips of grinding and the like. If the clamping is considered separately from the process, the term clamping between tips is also used .
A round body clamped between points is held on both ends in so-called centering bores by two centering points which exert axial pressure on one another. If a workpiece is clamped in this way and the torque is also transmitted on the face via face drivers , it can be machined over its entire length without reclamping. This significantly increases the concentricity and thus generally benefits the shape and position tolerances . The highest speeds are also possible, in particular with rotating centers. A so-called safety driver, on the other hand, transmits the torque via the rotary heart , which is clamped onto the workpiece as a driver . A disc surrounds the rotary heart to protect the operator. The counterpart is located on the spindle, which engages in the heart via a bolt and thus drives it. This means that only relatively slow speeds are possible, but damage to the face, as inevitably occurs with face drivers, is excluded.
Although the work piece cannot be machined over its entire length in one clamping with the safety driver, it still offers the basic advantages of clamping between centers. Due to the unique centering bores, the positional deviation of a workpiece or test piece between tips is relatively small, even after repeated reclamping. After production, it is advisable to use the existing bores to measure a component. The measurement errors of a test, for example a camshaft , are very small with this procedure.