BTA (Boring and Trepanning Association) deep hole drilling is used for producing holes with a high aspect ratio. In this process, chatter vibration sometimes occurs and a rifling mark is formed on the surface of the hole. The mechanism generating the rifling mark is considered to be self-excited vibration caused by a time delay. As a countermeasure, the authors analyzed the effect of the BTA machining head with three guide pads and suggested the optimum angle of the guide pads to prevent the formation of the rifling mark pattern. However, experimental approaches to clarify the mechanism and the countermeasure for the pattern formation phenomena in BTA deep hole drilling have not been established yet. In this paper, the pattern formation phenomena using the standard BTA tool are examined and the countermeasure of three optimally arranged guide pads is evaluated in experiments.
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