The taper in CNC lathe drilling may be caused by many factors, including tool selection, clamping method, cutting parameters, etc. Here are some common workarounds:

1. Tool selection: CNC lathe selects appropriate drill bit type and geometry to reduce taper. Ensure that the edge design of the CNC lathe drill bit is reasonable and the size matches the processing requirements.

2. Clamping method: Ensure that the CNC lathe workpiece is firmly clamped and the fixture design is reasonable to reduce CNC lathe vibration and displacement. Use the correct fixture for your CNC lathe to ensure a stable positional relationship between the workpiece and the tool.

3. Cutting parameters: Adjust the appropriate cutting parameters of the CNC lathe, such as cutting speed, feed speed and cutting depth, to reduce the impact of CNC lathe vibration and cutting force on the workpiece. Too high cutting parameters may cause workpiece deformation and increased taper.

4. Workpiece and tool alignment: Ensure the alignment accuracy between the CNC lathe workpiece and tool. If the axes of the CNC lathe workpiece and tool are misaligned, it will cause the drill hole to become skewed and taper increased.

5. Tool wear: Regularly check and replace severely worn tools on CNC lathes. Severely worn tools on CNC lathes can easily lead to reduced processing quality and increased taper.

6. Cutting lubrication: Ensure that the CNC lathe has sufficient cutting lubrication to reduce cutting heat and friction, thereby reducing taper.

7. Process monitoring: The processing parameters and workpiece quality are monitored through the processing process monitoring system, and problems that arise during processing are discovered and corrected in a timely manner.

8. Process optimization: Optimize the processing process according to the specific conditions of the CNC lathe. It may be necessary to adjust the CNC lathe processing sequence, clamping method or tool path to reduce taper.

By comprehensively considering the above factors and taking corresponding measures, CNC lathes can effectively solve the taper problem in drilling in CNC machining centers. If the problem still exists, it may be necessary to further analyze the specific situation and make targeted adjustments and improvements.