Page 154 - Demo

152 ISCAR GENERAL PURPOSE DRILLINGProblem Cause Solutionchipping on the cutting corners %u2022 Poor clamping of the chuck.%u2022 Check the clamping and adaptation. Use hydraulic clamping chuck, MAXINpower chuck or a shrink system. %u2022 Workpiece movement. %u2022 Increase workpiece chucking force.%u2022 Wrong drill. %u2022 Check drill type and drilling depth, cooling system and workpiece material. Possibly use longer drill.%u2022 Insufficient coolant. %u2022 Check cooling lubricant. Increase coolant pressure. In the case of external coolant supply, improve jet direction and add cooling jets.%u2022 Unsuitable cutting conditions.%u2022 Check cutting parameters, and possibly reduce feed.%u2022 Worn out or broken cutting corner.%u2022 Replace drill or regrind cutting edge.problem: burrs on exit %u2022 Unsuitable cutting conditions.%u2022 Reduce feed by 30-50% during exit.%u2022 Worn out drill. %u2022 Replace drill.rough surface finish %u2022 Unsuitable cutting conditions.%u2022 Adjust feed to improve chip flow.Ra%u2022 Large runout. %u2022 Make sure that the drill%u2019s runout is within 0.02 mm (radial & axial).%u2022 Chip jamming. %u2022 Reduce cutting speed.%u2022 . %u2022 Increase coolant pressure.%u2022 . %u2022 Apply pecking procedure.deviation of hole position %u2022 Large runout. %u2022 Make sure that the drill runout is within 0.02 mm (radial & axial).%u2022 Poor stability. %u2022 Check and improve drill and workpiece clamping rigidity.%u2022 Rough application. %u2022 When drilling hard materials or sloped surfaces, reduce feed by 30-50% during entrance.%u2022 . %u2022 Use a short pilot drill with 140%u00b0 point angle.