Troubleshooting Chucks
Filed under POWER CHUCKS
| 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. | |
| 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. |