CNC Cutting Machine Practice Test

What is one disadvantage of an open loop system in CNC machines?

1. Increased operating costs

2. Lower speed capabilities

3. Error accumulation potential

4. Higher maintenance requirements

The correct answer is: Error accumulation potential

An open loop system in CNC machines operates without feedback mechanisms to monitor and adjust the process. The primary disadvantage lies in the potential for error accumulation. Since these systems do not have the ability to detect discrepancies between the intended and actual tool paths, any small error that occurs during operation may not be corrected. This can result in progressively larger inaccuracies over time, particularly in production environments requiring high precision. This understanding of error accumulation emphasizes the contrast with closed loop systems, which actively monitor performance and adjust to minimize errors. Although other factors such as operating costs, speed capabilities, and maintenance requirements are relevant in evaluating a CNC system, they do not directly hinge on the absence of feedback that fundamentally characterizes open loop systems.