Tool Management

Tooling is a very important element in the running of a CNC machine tool not only for the productivity but also the accuracy of the parts machined. Some form of tool life management function needs to be present.

There are various systems available as part of modern CNC controllers, which are termed tool management systems that are able to keep track of the actual time for which each of the tool is in use. When the tools are entering the system (loading in the tool magazine), the expected tool life is entered in the controller memory along with all other tool related information such as offsets. This value is generally a conservative estimate of the tool life expected based on the work materials and the process parameters used. This value can be generally obtained from machine ability data banks used on the shop floor or from previous experience.

As machining proceeds with various components, the controller records the actual time for which each tool is used. This time used when subtracted from the expected tool life gives the left-over tool life for each tool. When the left over tool life is less than a certain nominal value, the controller initiates the action for replacing it by a sister tool. Controllers manufactured by Yamazaki, Fanuc, Sinumeric and others have this type of tool management option available with them.

It is also possible to have tool life monitored outside the controllers, for example the tool life of all the tools present in the manufacturing system consisting of more than one machine tool may be monitored in an IBM PC compatible.