Effects of CNC Tool Runouts on Drilling Process

Abstract

In this study, the surface roughness, dimensional accuracy and tool life that tool runout caused by CNC spindle mechanism based on metal mold manufacturing were investigated. In order to understand tool runout, spindle health measurement was performed: runout measurement with 300 mm test bar, spindle conical runout measurement, spindle pull force measurement and again spindle bearing vibration values were examined. In this study, spindle maintenance was performed and its effects on the final product before and after maintenance were investigated. Holes were drilled with 1, 2 and 3 times the drill diameter, the dimensional accuracy of the holes, the effect of runout on surface roughness in the hole drilling process and the runout and life of the drill bit used were investigated. The effects of runout before and after the maintenance were compared. Elimination of tool runout positively affected the surface roughness and parts with lower surface roughness were obtained. It positively affected the dimensional accuracy and the measurement tolerance was narrowed. Since the effect of tool runout on the cutting tool life is eliminated, its life is extended and the consumable cost is reduced. It has been observed that tool runout has a negative effect on machining in the hole drilling process with this experimental study.