Basic CNC Preventative Maintenance Program and Best Practice

Its amazing how little preventive maintenance is ever performed within the majority of manufacturing companies today. I am often asked by Maintenance personnel on how other companies take care of there CNC equipment. What's my answer? This is typical if its not broken do not fix it.

What I have outlined below is how you can set up a preventive maintenance program based on little knowledge of CNC and maintenance and minimal amount of downtime by covering the most basic and important parts of a PM program. The items below will save you the most money down and prevent a future breakdown.

Minimum Basic CNC preventive maintenance program

1. Check your machine oil levels – turret, B-axis, ATC & magazine gear boxes, spindle gear box, hydraulics. If you have a leak-fix it. You are contaminating your coolant, reducing your tool life and putting more contaminants into the oil system every time you fill the tank.

2. Clean chips out of every corner of the machine.

3. Pull back the waycovers and clean out the troughs in the ballscrew area and allow coolant to drain properly and avoid flooding into your bearing housings.

4. Check for lube on your box way machines. There should be a line from the wiper every time you reverse the axis on the leading edge.

5. Check the clamp force of the spindles every 3 months- this is a 15 second check. This PM check is so important- you could save a spindle, increase tool life and part quality.

6. Check your pallet change alignment and operation if equipped. The last thing you want to do is throw a fixture in a machine. Also clean chips from under the pallets and B-axis

7. Perform a basic inspection of cables, hoses and electrical fans on the outside and inside of electrical cabinets. Do not forget to check the drive fans or computer fans as well.

8. Clean & replace any filters as necessary.

9. Check your CNC tool change alignment. Maybe not the easiest for a novice but at least look at it for something obvious. Fix any CNC machines that are dropping tools on occasion. There is a reason! Do not let it go. Damages to waycovers, ATC cam followers and gear boxes, tool fingers, and spindle damage will occur.

10. Check your backup batteries and make backups of parameters through your DNC system. With today's economic times many machines are powered down for intensive periods of time. Hope you have backups or original data sheets.