System Interactions

A machining process is an interaction of geometric, kinematic and dynamic, physical, chemical, and tribological phenomena. It is not necessary to fully understand all these interactions to achieve a satisfactory process, but it is necessary to be aware of the factors that can influence the outcome and seek to determine best practice for each part of the system. For a better understanding of system interactions, the reader is referred to Tribology of Abrasive Machining Processes by Marinescu et al. [2004].

Examples of the influences on centerless grinding accuracy are illustrated in Figure 19.6. The input to the process is viewed as the feed motion and the output as workpiece shape and quality. Quality is defined by size, roughness, roundness, straightness, surface integrity, etc. For high accuracy work, there are many factors that determine accuracy and quality. For example, [9]

So far, discussion has been limited to accuracy and quality. There will also be concern for productivity and costs. Productivity is the rate at which goods can be produced to specified quality levels. Productivity and costs are closely related.

An improvement in accuracy capability of a machine is usually accompanied by higher pro­ductivity. This is because the manufacturer works to specified tolerances and quality levels. If the machine is capable of better quality, the manufacturer can increase the rate of production and remain safely within tolerances. The manufacturer also seeks to reduce process costs for specified quality levels. This can often be achieved by increasing wheel speed, changing to high-performance abrasives, improved machine structures, improved feed cycles, and improved control systems. The following sections discuss relevant aspects for optimizing system performance.

Updated: 24.03.2016 — 12:02