Effect of Drill Bit Sizes and Workpiece Material on Vibrations in a Drilling Machine

Abstract

Vibrations are known to negatively affect drilling operations which
is a widely used machining process for creating holes. In this work,
different materials were drilled using varied drill bit sizes while
simultaneously measuring the vibrations at different parts of the
machine. ANOVA (two steps without replication) was used to
analyze data, and then regression models were developed. Higher
amplitudes observed at the electric motor indicated that it is the major
source of the vibrations. The vibrations in all the parts of the machine
investigated were found to vary significantly with different sizes of
drill bits and material of the workpiece. Also, the variations in
vibration parameters showed a good fit with regression models of
power 3, having R-values of 1. Conclusively, vibration during
drilling operation can be affected by a number of factors, the electric
motor being the most contributing factor.