Impact of drill bit feed rate and rotational frequency on the evaluation of wood properties by drilling resistance measurements

Abstract

ABSTRACTIML-Resi PD-400 drilling tools (IML System GmbH, Wiesloch, Germany) were used to study the influence of the feed rate and the rotational frequency of the drill bit on the drilling resistance (DR) measurements. The study presents theoretical aspects concerning chip formation, kinematics (speeds, cutting angles, chip thickness) and cutting forces distribution during the drilling process. Drill bit rotational frequency and feed rate have an impact on nominal chip thickness or a feed rate per major cutting edge of the drill bit, and were correlated to DR measurements. Varied rotational frequency and feed rate had a significant impact on DR and feeding resistance (FR). Positive correlations between feed rate per major cutting edge and DR (FR) for the individually tested wood species can be described by allometric functions (R2 = 0.93–0.99). Wood density had a partial impact on correlations between feed rate per major cutting edge and DR (FR).