Cnc Mill is also the machining center we often say. It has high automation and high precision characteristics and plays an important role in modern  cnc manufacturing. Many unexpected things often occur in the machining process of Cnc Mill, and the failure of the spindle is one of them. Spindle failure will affect the normal processing of the machine tool or smooth workpieces. We must analyze the reasons comprehensively and find a solution to the problem.

1. Cnc Mill spindle heats up and rotation accuracy decreases

In the case of this kind of problem, the precision of the processed hole is generally low and the cylindricity is also poor.

Cause analysis: The centering taper hole of the Cnc Mill spindle is damaged, which may be caused by errors in the process of pulling and inserting the tool.

• (1) The lubricating grease does not meet the requirements, resulting in poor lubrication of the bearing and generating a lot of heat and noise.
• (2) The tapered hole positioning surface of the positioning tool in the spindle is damaged, resulting in a slight eccentricity of the processed hole.
• (3) The pre-tightening force of the front bearing of the main shaft decreases, which causes the bearing clearance to increase;
• (4) The spring of the automatic clamping device inside the spindle fails due to fatigue, and the tool cannot be fully tightened and deviates from its original position.

2. Cnc Mill’s tie rod steel ball is broken

The limit switch stopper is installed at the end of the cylinder of the gas-liquid pressurized cylinder. Although the cylinder piston is in place, the pressurizing cylinder piston is not in place. As a result, the manipulator forcibly pulls the knife before the tool handle is completely released, which damages the tie rod. Steel balls and tightening screws.

3. Damaged Cnc Mill spindle positioning parts

This situation will cause the machine tool to have a loud impact when changing tools, and the positioning key that rotates the tool holder at the front of the spindle will be locally deformed.

The loud noise in the tool change process occurred in the inserting stage of the manipulator. The reason was the error of the exact stop position of the spindle and the drift of the reference point of the spindle tool change. CNC Machining centers usually use Hall elements for orientation detection. The fixing screws of the Hall elements are loose after long time use, which causes the keyway of the tool holder to not align with the positioning key on the spindle when the manipulator inserts the tool, so the positioning key will be damaged.