There are a few key ways to use a CNC vertical machining center (VMC) machine efficiently:

1. Properly set up the machine: Make sure the machine is level, the guides and gibs are properly adjusted, and the tool holders are tightened to the correct torque.
2. Use the right cutting tools: Choose cutting tools that are suitable for the material you are machining, and that are in good condition. This will help ensure good surface finishes and prolong the life of the tools.
3. Use the right cutting speeds and feeds: The cutting speeds and feeds should be set to match the material, tool, and operation.
4. Use a cutting fluid: A cutting fluid can help reduce heat, prolong tool life, and improve surface finishes.
5. Properly program the machine: Use good programming techniques and make sure the program is free of errors before running the machine.
6. Monitor the machine’s performance: Keep an eye on the machine while it’s running, and check for any unusual noises or vibrations. This will help you detect problems early, before they lead to costly downtime.
7. Keep machine clean and well-maintained : Regular cleaning and maintenance will help ensure that the machine runs smoothly and will help prevent breakdowns.
8. Properly train the operators and use standard operating procedures: The operators should be properly trained and should follow standard operating procedures to ensure that the machine is being used correctly and safely.