Circular saw vibrations or dynamic behaviour of the spindle

Sawing of wood with circular saws is a typical example of cutting with multi-blade tools. In that kind of cutting, the position accuracy of following tool blades is a crucial factor which affects the cutting process and machining final effects. Position tooth errors may cause deterioration in cutting conditions, changes in loads of individual teeth and the tool as a whole, and also a decrease in accuracy and surface quality after cutting. The circular sawing machine spindle system behaviour may be examined either in a static system or a dynamical system. In the static system a precision of circular saw blade clamping on the spindle and a static accuracy of the spindle axis of rotation are important factors of the spindle system. On the other hand, in the dynamical system first of all cutting forces and forces resulting from the spindle rotary motion are additional factors which crucially affect the spindle behaviour. Obtained experimental results of dynamics investigation of the circular sawing machine spindle system have revealed that both the spindle rotational speed value and a method of the spindle driving crucially affect behaviour of the circular saw spindle system and also effects of sawing. Furthermore, dynamical behaviour of the circular saw blade in a function of the rotational speed was examined. Those experiments revealed that the effect of the critical rotational speed of the circular saw blade on the circular saw blade axial run-out is rather small in the examined case of the circular sawing machine.