Tool Presetting for Deep Hole Drilling Operations
Tool presetting is one of those steps that operators skip to save five minutes, then spend two hours recovering from the crash that follows. In deep hole drilling, the tool setting accuracy directly determines bore diameter, surface finish, and tool life. I have made a habit of measuring every tool before it goes into the spindle, and the data has shown me patterns I never would have caught otherwise. Why Presetting Matters for Deep Hole Drilling A gun drill with 0.02 mm runout at the tip will produce a bore 0.03 to 0.05 mm oversize, depending on the material and feed rate. That may not sound like much, but if your tolerance is ±0.025 mm, you are already out of spec. The relationship between runout and bore quality is nonlinear. I have seen a 0.01 mm increase in tip runout produce a 0.025 mm increase in bore diameter. ...