Page 99 - Demo

97GENERAL PURPOSE DRILLINGTroubleshootingDeviation of Hole Tolerance1 Check the runout and make sure it is within 0.03 mm T.I.R. (radial and axial cutting points).2 Reduce feed rate.3 Check the chisel point runout and make sure it is within 0.03 mm T.I.R.4 Worn cutting edge. replace head.5 Increase workpiece chucking force.6 Increase internal coolant pressure. D nominal%u00d8 > D nominal + 0.15mm%u00d8 < D nominal - 0.03mmSurface Finish Too Rough1 Check the runout and make sure it is within 0.03 mm T.I.R. (radial and axial).2 Adjust the feed for improved chip formation.3 In case of chip jamming - increase the coolant flow and/or reduce the cutting speed.4 Increase the coolant pressure.5 Check the chisel point runout and make sure it is within 0.03 mm T.I.R.6 Use pecking cycle.7 Replace the drilling headRaHole Not Straight%u2022 Drill a pre-hole for centering (check recommendations for pre-hole operation).%u2022 Increase coolant pressure; improve jet direction in case of external coolant supply.%u2022 Increase the feed.Inaccurate Hole Position1 Check the runout and make sure it is within 0.03 mm T.I.R. (radial and axial).2 Check the stability of the machine spindle, tool and workpiece clamping rigidity.3 When drilling rough, hard or sloped surfaces (up to 7%u00b0), reduce the feed rate by 50%-70% during entrance.4 Drill a pre-hole with a 140%u00b0 point angle for centering.5 Check the chisel point runout and make sure it is within 0.03 mm T.I.R.Burrs on Exit1 Reduce the feed rate by 50%-70% during exit.2 Replace the worn head.