Turn+: A MATLAB-based software for dynamic turning, chatter analysis, and surface roughness prediction

Turning and boring processes are widely used to machine shafts, tubes, casings, and rings across sectors from automotive to aerospace, yet productivity is often limited by regenerative chatter, which couples cutting mechanics with tool–workpiece dynamics, affecting surface finish, reducing tool life and leading to conservative process parameters. Turn + addresses this gap with an open-source MATLAB application that unifies cutting-force prediction, dynamic-stability analysis, and surface-roughness estimation for external turning and boring. Through an intuitive interface, users specify tool geometry, cutting coefficients, and machine-tool modal data. Turn + then integrates the regenerative delay-differential equation with a semi-implicit Euler scheme to predict time-domain forces and displacements. A built-in post-processor generates stability-gradient maps and reconstructs the tool-nose path to estimate average roughness, revealing how cutting parameters influence chatter and finish. Validation against classic analytical solutions and cutting tests shows agreement within 6 % for the critical depth of cut and 8 % for average roughness. A modular architecture separates the GUI from solver engines, enabling straightforward integration of new force models and advanced operations such as pinch or parallel turning. Turn + provides an accessible, rigorous platform for education, research, and industrial process planning to improve productivity and repeatability.