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

Spiralling in BTA deep-hole drilling – How to model varying frequencies

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 the formation of spiralling has to be prevented. Gessesse et al. (1994) explain spiralling by the coincidence of bending modes and multiples of the rotary frequency. This they derive from an elabora...

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 ...

Deriving a statistical model for the prediction of spiralling in BTA deep-hole-drilling from a physical model

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...

Experimental Investigation of the Dynamics of the BTA Deep Hole Drilling Process*

Deep hole drilling methods are used for drilling holes with a high length-to-diameter ratio, good surface finish and straightness. Due to the slender tool-boring bar combination needed for producing holes with a high length-to-diameter ratio, the process is susceptible to dynamic disturbances. These disturbances can be classified as chatter vibration or spiralling. The work presented in this pa...