Axial Deviation of Hole in Deep Drilling (2nd Report)

Spiralling in BTA Deep-hole Drilling: Models of Varying Frequencies

Statistics and Time Series Analyses of BTA Deep Hole Drilling

BTA 1 deep hole drilling is a method for producing precision bores with high length to diameter ratios. The long and slender tools feature low torsional and bending stiffness. This may lead to undesirable dynamic disturbances of the machining process usually classified as either chatter vibration or spiralling. Prediction and identification of the causes of these process failures is important f...

Allergic contact dermatitis by Boswellia carterii ointment in a deep 2nd degree burn wound: a case report

Numerous scientific texts insist on safe topical application of specific herbal products like those containing Boswellia oleogumresin, but adverse effects arising during clinical trials of herbal medicines give the opportunity to clarify the blind spots in the area of drug safety. A 36-year-old woman without allergic background had two burn wounds because of hot oil. Her hand's wound w...

Prediction of spiralling in BTA deep-hole drilling – estimating the system’s eigenfrequencies

One serious problem in deep-hole drilling is the formation of a dynamic disturbance called spiralling which causes holes with several lobes. Since such lobes are a severe impairment of the bore hole quality the formation of spiralling has to be prevented. Gessesse et al. [2] explain spiralling by the coincidence of bending modes and multiples of the rotation frequency. They derive this from an ...

Application and Use of Multivariate Control Charts in a BTA Deep Hole Drilling Process

Deep hole drilling methods are used for producing holes with a high length-to-diameter ratio, good surface finish and straightness. The process is subject to dynamic disturbances usually classified as either chatter vibration or spiralling. In this paper, we will focus on the application and use of multivariate control charts to monitor the process in order to detect chatter vibrations. The res...