Tool stability analysis for deep hole drilling

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...

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

Non-conservative oscillations of a tool for deep hole honing

The dynamics of a rotating tool, commonly employed in deep hole honing, is considered. A mathematical model of the process including a dynamic representation of tool, workpiece surface and honing stones interaction is suggested and analyzed. It is shown that interaction forces are non-conservative. The honing tool is modeled as a rotating continuous slender beam with a mandrel attached at an in...

Deep drilling moves ahead

Deep-water drilling in the Gulf of Mexico could resume within weeks under a policy by the US government, which has come under increasing criticism from the oil industry and politicians in the region over the impact of the drilling halt and worries from scientists that the full impact has not yet been assessed. Oil and gas exploration in the gulf’s deep waters has been stopped since May, when Ob...

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 ...