Quality Inspection in CNC Machining: The 6 Most Important Aspects

CNC machiningQuality Control: The 6 Most Important Aspects

As for the parts, quality controlIt is indispensable across all industries, and the same applies to manufacturing processes; quality control is essential for products, equipment and machinery alike. Manufacturers today increasingly opt for CNC machining over traditional machining methods, as the former offers numerous advantages, such as higher productivity and improved process efficiency. Nevertheless, quality inspection remains a crucial stage in the manufacturing process. Quality control and inspection must be carried out at every stage of the machining process.

Furthermore, quality assurance is a key element of the manufacturing process; unlike quality control, it requires manufacturers to establish quality inspection procedures, which must be carried out regularly by CNC operators, and it also requires manufacturers to use appropriate supporting documentation to report the results of these inspections, Therefore, the quality assurance process establishes protocols and documentation, whilst quality control is the process of applying these protocols and documentation under routine circumstances or as and when required.

Here, we will explore just how important this type of quality inspection is, and we will also discuss the programmes used in CNC machining.

There are three modes of quality inspection for CNC machining

1. Testing the accuracy of machine tools

At this stage, the machine tool is calibrated and its operational accuracy is checked. Other factors to be considered include the spindle orientation, the support structure, the axes, and so on. All physical components must maintain the correct relationship with one another. For example, the column of a vertical machining centre must be perpendicular to its own bed. Furthermore, it is vital to check the alignment of the linear axes.

2. Assessment of parts or products

At this stage, dimensional and positioning checks are carried out on the parts; these checks cover variables such as orientation, surface finish and contour. In addition, geometric and dimensional tolerances are checked in accordance with specifications or intended purposes.

3. Process Control and Monitoring

Monitor every stage of the process to prevent process-related inefficiencies, which could lead to faults, malfunctioning products or unexpected bottlenecks. The product lifecycle is divided into several stages, beginning with the conceptual phase. This is followed by the design phase, the feasibility analysis phase, the evaluation phase, the prototyping phase, the testing phase, the mass production phase, and so on. At every stage, quality control is an integral part of the process.

When manufacturing specific components using CNC machine tools, attention must be paid to the status of the key parameters to be checked during the CNC machining quality inspection process; As the objectives of rapid prototyping must be met, we must verify whether the system meets the requirements in terms of the desired product and its prototyping capabilities. When assessing the performance, reliability and quality of CNC machines, the following indicators should be taken into account:

Every effort must be made to achieve precise geometric dimensional tolerances, whilst ensuring that the machine operates within extremely narrow error limits to meet the specified accuracy levels.

Inspect the spindle of the CNC machine.

Check the equipment to ensure it has been accurately calibrated; otherwise, its accuracy will gradually deteriorate over time.

Record the results of the inspection for future reference.

To ensure credibility, please consider the ISO certification level.

If you are planning to outsource this role, it is essential to ensure that the service provider is reliable and to establish a stable channel of communication.

Should any personnel lease or purchase such equipment for the purposes of their business, it is essential to ensure that all specifications are assessed and that a warranty is obtained.

Six Key Methods for Quality Control and Inspection in CNC Machining

1. Effective communication

Throughout the entire manufacturing process, or following the dispatch of prototypes, it is absolutely vital to maintain timely communication with the client. This is because buyers and consumers have specific requirements regarding the product’s characteristics and functions.

2. Understanding product design

Engineers must carry out a thorough assessment of the design of the final product’s CAD model, understand the product specifications and requirements set out by the client, and double-check every aspect before production begins. We should adopt the most cost-effective approach to processing parts, adjusting the numerous variables involved in the entire CNC machining operation, and verifying that requirements are met.

3. Services and Products

Design, standards, router production, procurement documentation, and inspection and testing protocols set out monitoring and testing procedures for all precision products.

4. Verification of procured products

Every item purchased must undergo a visual inspection by a receiving inspector; for authorised products, a technical quality control (QC) inspection must also be carried out.

5. Process inspection

Process inspection includes first-piece inspection and operator checks, which are used to ensure the quality of completed orders and to achieve on-time delivery.

6. Final inspection