Problem |
Possible Reasons |
Countermeasures |
Chuck will not operate. |
The inside of the chuck is broken. |
Disassemble and replace part. |
Slideway seizes. |
Disassemble and repair damaged part with oil stone or replace it. |
Hydraulic cylinder is not operating |
Check that pressure reduction valve, change over valve and hose system are correct. |
Insufficient master jaw strokes. |
Proximity sensing switch set incorrectly |
Reset switches. |
Too much swarf in chuck. |
Disassemble and clean. |
Drawtube is loose. |
Remove and retighten it. |
Drawnut position is incorrect. |
Reset drawnut position. |
Workpiece slippage. |
Insufficient master jaw stroke. |
Position master jaw so that it is in stroke centre when workpiece is gripped. |
Insufficient clamping force. |
Check that hydraulic pressure is adequately set. |
Formed diameter of top jaw does not match workpiece diameter. |
Reform top jaw according to the correct method. |
Cutting force is too high. |
Calculate cutting force and reduce it to the correct chuck specifications. |
Insufficient lubrication on master jaws and each slideway. |
Lubricate from grease nipple and grip and grip again jaws without workpiece in chuck. |
Speed is too high. Marking is found by mis-alignment such as work feeder, steady rest, tailstock, etc. |
Reduce speed up to necessary gripping force. Secure alignment to eliminate marking. |
Poor accuracy |
Periphery of chuck is run out. |
Tighten bolts correctly. |
Foreign matter is caught in serrations between master and top jaws. |
Remove top jaw and clean serrations thoroughly. |
Top jaw mounting bolts are inadequately tightened. |
Tighten bolts to correct torque. |
Forming of top jaw is inadequate. |
Check that forming plug is parallel to chuck and face and plug is not deformed due to gripping force. |
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Also check hydraulic pressure while forming and face roughness. |
Top jaw is deformed and top jaw bolts are extended because top jaw is too high. |
Reduce height of top jaw by replacing with standard size jaw. |
Workpiece is deformed by too much gripping force. |
Reduce gripping force to prevent deformation. |