Design and Analysis of Helical Needle Tip Grinding Process

A generalized helical needle tip geometry model, which can describe many typical needle tip geometries, including conical, bevel, blunt and helical shapes with proper geometric parameters, is presented based on analogy to the helical point drill geometry. The generality of this model offers a general way for manufacturing various needle tip geometries. A mathematical model of the helical needle tip geometry is provided along with the formulation of the kinematic model of the tip grinding process. The control strategy on a 5-axis grinding machine system is also developed to implement the designed kinematic model. The needle tip’s motions in the grinding process are simulated to characterize the effects of grinding parameters on needle tip properties and to predict the trajectory of the needle tip point during the grinding process. Finally, several types of needle geometries have been manufactured by the developed grinding process to verify the newly formulated models.