Long tool overhangs can cause a turning tool to oscillate when boring internal geometries. In addition to the resulting chatter marks on the surface, these vibrations also lead to a significant reduction in tool life.
For unfavourable length/diameter ratios, the experienced machinist relies on vibration-damping boring bars, which enable low-vibration machining but which can still vibrate during certain machining operations. Paul Horn GmbH has addressed this problem and is presenting a boring bar that can be adjusted to the vibration amplitudes that occur. Precise adjustment of the damping element in the boring bar enables a vibration-free grooving process. This results in better surface quality without chatter marks and a significant increase in tool life.
The exact adjustment of the damper, made of a carbide rod supported in O-rings, is made from the outside via an adjustment screw. Adjustment is achieved by fine-tuning the pre-tension of the O-rings. This allows the boring bar to be precisely set according to the vibration occurring in each application. As standard, Horn offers the tools from stock in the length/diameter ratios 5 x diameter and 8 x diameter. Higher ratios are possible as special tools. For the grooving processes, Horn offers the S224 double-edged grooving system. The Horn cassette system BK 224 ensures a stable interface between the boring bar and the inserts. To further increase process reliability, the boring bars are equipped with an internal coolant supply.
