How can operators effectively monitor tool wear in CNC milling?

Monitoring tool wear in CNC milling is crucial for maintaining part quality and operational efficiency. Observing cutting performance and surface finish is a direct and reliable method for assessing tool wear. As a cutting tool wears down, its ability to cut efficiently decreases, leading to noticeable changes in the surface finish of the machined part. Operators should keep an eye out for signs of poor surface quality, such as roughness, chatter marks, or dimensional inaccuracies, which indicate that the tool may need to be replaced or re-sharpened.

In addition to surface finish, variations in cutting performance can also signal tool wear. For instance, operators might notice increased cutting forces or a decline in the speed and feed rate due to excessive wear. Recognizing these changes allows operators to take proactive measures to replace tools before they can significantly impact production quality or lead to tool breakages, which can cause machine downtime.

While tracking power consumption of the machine, checking operational speed, and reviewing the machining timeline might provide useful information about the overall performance of the CNC machine, they do not specifically target the changes caused by tool wear as effectively as observing cutting performance and surface finish would. Thus, option B stands out as the most effective approach to monitoring tool wear.