How to Repair a Machined Lip

Place the engine lathe’s spindle in neutral with the speed selector levers located on the lathe’s control panel. This allows you to freely spin the spindle with your hands.

Place the object into the jaws located on the spindle with the machined lip facing outward. Tighten the jaws of the spindle lightly with the spindle wrench. Do not over-tighten the jaws at this time.

Place a magnetic dial indicator onto the turret of the lathe and then turn the carriage handle counterclockwise to being the turret towards the machined lip. Position the shaft extending from the dial indicator so the tip rests against the machined lip. Turn the dial on the indicator so the needle lines up with zero.

Turn the spindle manually as you watch the dial. The dial will move. Turn the spindle until you reach the highest negative number on the dial. Tap the opposite side of the object with a rubber mallet to square the object in the jaws. Repeat this process until the dial does not move more than .005 inch during a complete spindle rotation.

Tighten the jaws on the spindle with a spindle wrench to lock the object in the jaws.

Select an RPM speed of 150 to 300 with the speed selector levers located on the lathe’s control panel. Select the slowest possible feed rate for the carriage via the selector levers on the control panel.

Slide a carbide turning tool into the turret on the carriage and then tighten the turret bolts with the turret wrench.

Turn on the lathe and then manually bring the carriage forward until the tip of the turning too just touches the outside edge of the machined lip.

Lift the directional lever on the carriage so the turret will move across the face of the object instead of down the length of the object.

Press down on the feed lever that engages the turret and wait until the turning tool feeds across the machined lip. This will remove the damaged material from the lip's surface and leave a new machined lip.