CNC machines are very useful, and long-lasting pieces of machinery are used to carry out various machining operations on workpieces. The high accuracy, remarkable productivity, robust capabilities, and diversity of CNC machining services have contributed to their ever-increasing demand. But if we don’t maintain it appropriately or carry out certain operations incorrectly, its productivity and the quality of its output will suffer. The most typical causes of such errors with CNC machines are operator mistakes and improper upkeep of the equipment. To know the answers to the problems that have been identified, it is important to first identify the root cause of these errors.
The term “machining error” refers to how the actual geometric characteristics of the parts following machining deviate from the ideal structural parameters. Machining errors may occur when a component is not machined precisely enough. The term “machining accuracy” refers to the degree to which the actual design parameters of the component and the desired geometric parameters of a part after machining agree with one another. There are various kinds of errors. Some of them are listed below.
1. Manufacturing Errors
Spindle rotational error, guide rail error, & transmission chain error are the most common production faults in machine tools. Spindle rotation error is the difference between the spindle’s actual rotation axis and its average rotational axis at any given time, which directly impacts the processed workpiece’s accuracy. Spindle coaxial error, real influence itself an error, a coaxial error between both the bearings & the spindle winding are the major causes of spindle rotation error. The guide rail serves as a reference point for identifying the relative location of different machine tool modules on machine tools and industrial machinery movement. The guide rail mistake is caused by many variables, including the guide rail’s manufacturing defect, uneven wear, and poor installation quality. The mistake of relative movement between the transmission components at both extremities of the transmission chain is known as transmission chain error. It is caused by manufacturing and assembly flaws in each transmission chain component and wears from usage.
2. Tool Geometric Error
Another very well-known error is caused by the tools we use side by side in CNC machining. During the cutting process, every tool will eventually wear down, causing the size and form of the workpiece to alter. The impact of tool geometry error on turning process error varies by tool type: when using fixed-size techniques for machining, tool manufacturing error will have a direct impact on the workpiece’s machining accuracy, and for general tools, the manufacturing error will have a less direct impact. Machining mistakes are not affected directly.
3. Positioning Error
A positioning pair consists of the workpiece placement surface & the fixture positioning element. The incorrect manufacturing mistake of the positioning pair is the maximum position variation of the workpiece induced by the inaccurate processing of the standing pair and the matching gap between positioning pairs. The positioning pair’s incorrect manufacturing mistake can only occur when the adjustment technique is utilized; it will not occur when the trial cutting technique is applied.
4. Error in Adjustment
The process equipment must be changed in some manner throughout each machining step. An adjustment mistake arises because the correction/adjustment cannot be 100% correct. By changing a machine tool, fixture, or workpiece in the workflow, the mutual position correctness of the workpiece & the tool just on the machine tool is assured. The adjustment error plays a critical part in the machining mistake when the initial precision of machine tools, fixtures, and workpiece blanks fulfills the process requirements before considering dynamic variables.
5. Error in Measurement
Man made errors are one of the reasons that humans are being replaced by robots in industry. The measurement technique, the precision of the measuring instrument, the workpiece, and subjective and objective variables all impact measurement accuracy when measuring components during or after processing. Hence, to remove such errors it is important to
6. Internal Anxiety
What if we say that, instead of physical errors, the errors can also be caused by a mental state of an operator of the machine. Stress can lead to errors. Internal stress is the tension that occurs within a portion without applying external force. The workpiece metal would be in a high-energy abnormal state, intuitively converting to a low-energy steady position, followed by deformation, causing the workpiece to lose its initial machining precision.
The machining error, degree of conformance, and machining accuracy all improve in direct proportion to the size of the decrease in the machining error. Machining accuracy & machining inaccuracy are two different ways of talking about the same issue. Because of this, the amount of machining precision may be inferred from the magnitude of the machining mistake. For a successful CNC machine worker, knowing all about these errors is essential. So that one can come up with a credible solution. We hope this article will help you identify the CNC machine errors.