Damped boring bar – what is it, and how does it help in boring ?
A damped (also called tuned) boring bar has a hollow body with an inertia mass suspended between rubber bushes one at each end. The inertia mass is surrounded by a special oily liquid. When vibration starts, the dampening system absorbs the energy of the vibrations and minimizes it. Damped boring bars are used for high L/D ratios. This post talks about L/D ratios and reducing vibrations in boring.
Pre-tuned boring bars are adjusted to a particular L/D ratio (e.g., 10). If you want to use such a bar at a different L/D ratio, you have to re-tune the bar. Re-tuning basically means moving the internal inertial mass axially, done by rotating screws on the outside of the bar. You do this by actually taking trial cuts and rotating the screws by amounts specified by the manufacturer of the tool. Text source: Cadem NCyclopedia multimedia CNC training software. CAD/CAM software,CNC Program Simulation,CNC Training Software
