Enhancement of accuracy in double sided incremental forming by compensating tool path for machine tool errors

Incremental Sheet Forming (ISF) is a dieless forming process and has capability to form complex 3D geometries. Double Sided Incremental Forming (DSIF) is the most flexible variant of ISF as it uses two tools, one on either side of the sheet (one tool forms the sheet and other acts as support). However, forming the components with acceptable accuracy is one of the challenges as it depends on many factors such as sheet and tool(s) deflections as well as machine tool errors. If these deflections/deviations are not compensated in tool path, accuracy of the component gets affected and support tool may lose contact or squeeze the sheet while forming components. In the present work, grid-based method is used to measure the machine tool error at discrete points of the work envelope. To enhance the accuracy and support tool contact condition, machine tool errors are compensated in tool path along with tool and sheet deflection compensations developed earlier. To demonstrate the effectiveness of developed methodology on the accuracy, components having different geometric characteristics as well as opening sizes are formed with and without compensating for machine tool errors in tool path. Results indicate that deviation in symmetry within the same contour reduced from 850 mu m to less than 40 mu m. In addition, support tool has maintained contact throughout support surface with maximum force of 50 N when machine tool errors are compensated.