The current trend in the market to solve long boring bar related chatter problems are passive dampers integrated in the boring bar, which has derived in patents and commercial products; This solution, however, is not feasible in very slender bars or trepanning operations, due to small space available in the tool. Active damping has been tested and indus-trialised in different applications, including machine tool structures, but never in internal turning tools. The application of active damping on boring bars has been proposed in several researches…