Tool Wear During CNC Machining: Types and How to Avoid Them

by | Aug 8, 2017 | CNC Machine Tools, CNC Machining

CNC Tools

The introduction of CNC machining has revolutionized the way our industry processes goods.

The dependency on human labor has been reduced to half, with computers taking their place. As a result, we are able to witness an increased efficiency, improved product quality and the ability to produce almost everything with exact precision- 3D, 4D or 5D.

But then again, it’s a computer system directing actual ‘CNC machines’ to perform a task. Tool wear is as common as it gets. It may experience a breakdown or failure after working for an extended period of time. In fact, every cutting tool will experience wear at some point in its production life.

While it might be common, excessive wearing is not good for our product or machine. The inconsistencies caused by such wears and tears may have unwanted effects on your workpiece and may do damages to the primary piece of equipment. Its failure might even lead to irreplaceable damages such as rework, a collection of scrapped parts, or a total breakdown which might cost us more than the product itself.

Thus, it’s pretty important to find out such abnormalities and correct them in real-time so we get optimal end mill performance. Here’s our take on the various types of tool wear, and how to identify and mitigate them, complied with our experience. Hope they will help you manage tool wear better!

Abrasive Wear

Mechanical stress is one of the major causes of tool wear with thermal taking a close second place.
Abrasion, especially the wear land abrasion, is pretty common amongst cutting tools. It is caused by the uniform abrasion on the cutting edge of the tool, dulling the edge as a result. If severe like added thermal stress at higher speeds, it can even alter the dimensions of the tool edge. This is why a tool coating is of utmost importance for tool longevity.

 

How to Avoid

If you start witnessing a certain abrasion pattern on your tool’s edges, it’s time for you to reduce the cutting speed and optimize coolant usage, especially when working with this particular tool. Even High-Efficiency Milling (HEM) tool paths can be used to reduce wear by distributing the work done across the entire length of the cut. This helps focused abrasion while contributing to the longevity of the tool life.

 

Thermal Cracking

Thermal cracks are caused by temperature fluctuations during a milling process. They are identified as a series of cracks on the tool’s surface perpendicular to the cutting edge. Such cracks form over a long period of time and are often the most difficult to deal with once present.

How to Avoid

One of the best ways to divert thermal cracking is to add a proper heat-resistant coating to the end mill. Similar to abrasion wear, HEM tool paths can also be utilized for an even distribution of the head across the tool, thus reducing the heat on a certain area.

 

Fracture

Fracture, as the name suggests, refers to the sudden breakage of a tool during a machine operation. It, of course, results in improper speeds and feeds, and incorrect coating, thus spoiling the product or part in hand altogether.
Such fracture cases aren’t restricted to abrasion or wear only. A loose handle, inconsistent workpiece, incompetent materials, or other tool holder issues can cause them too.

 

How to Avoid

You may go ahead and adjust the speed, feed and depth of the cut to keep the tool fracture at bay. Checking the machine set up of appropriate rigidity and optimizing coolant usage can also help reduce fracturing.

 

Chipping

Chipping is caused by a number of different reasons such as excessive shock-loading during operation, thermal cracking or abrasion. It can be seen as a series of chips or flaked bits on the cutting tool. This type of wear often leads to a poor surface finish and may even cause a severe tool failure if not corrected in time.

 

How to Avoid

There are several steps to check whether your cutting tool is experiencing chipping or not. First, you need to ensure your CNC milling machine is free of vibration or chatter. Then adjust your speeds and feeds accordingly, increase the speed and reduce the feed rate.

 

Importance of Planning & Strategy Before Starting Your CNC Machining Project

by | Feb 1, 2017 | CNC Machine Shop, CNC Machining, Machine Shop

planning & strategy

CNC (Computer Numerical Control) machining is a game-changer in manufacturing, enabling the creation of precise, complex parts for industries like aerospace, automotive, and medical devices. However, the key to a successful CNC machining project goes beyond having advanced equipment and skilled operators—it starts with meticulous planning and strategy.

Think of embarking on a road trip without a map. While you might eventually reach your destination, you’d face unnecessary detours, wasted time, and frustration. Similarly, diving into a CNC machining project without proper planning can lead to costly errors, delays, and subpar results. Proper planning is your roadmap, guiding every step from understanding project requirements to material selection, part design, and quality management.

In this blog, we’ll explore why thorough planning and strategic thinking are essential for the success of your CNC machining projects. From defining objectives to managing risks, we’ll show how to ensure your journey from concept to finished product is smooth and efficient. Let’s lay the groundwork for success by highlighting the importance of planning and strategy in CNC machining.

#1 Understanding the Project Requirements

Understanding project requirements is crucial for the success of a CNC machining project. This involves clearly defining the project scope and setting measurable, achievable goals. A well-defined scope prevents scope creep and ensures all stakeholders are aligned on deliverables, resources, and timelines.

For example, a precise scope might state, “Produce 500 aluminum brackets with a tolerance of ±0.01 mm, using 6061 aluminum alloy, by July 31, 2024, adhering to ISO 9001 standards,” whereas a vague scope like “Make some aluminum parts quickly” can lead to confusion.

Setting SMART goals—Specific, Measurable, Achievable, Relevant, and Time-bound—is also essential. Goals should align with client or business needs, such as reducing production time or improving quality. For instance, aiming to “increase machining accuracy by 10% within six months by implementing new calibration techniques” is a clear and actionable objective. By defining the scope and setting aligned, measurable goals, you create a solid foundation for your project’s success.

#2 Material Selection

Material selection is crucial in CNC machining projects as it impacts the quality, cost, and feasibility of the final product. Common materials include metals (aluminum, steel, brass), plastics (ABS, polycarbonate, nylon), and composites (carbon fiber-reinforced polymers). Each material’s properties, such as hardness, tensile strength, and machinability, must be evaluated to ensure suitability for the project’s requirements.

Additionally, the cost and availability of materials play a significant role. Choosing cost-effective, readily available materials helps maintain the project budget and timeline. The right material choice ensures efficient machining, minimizes tool wear, and avoids delays, ultimately contributing to the project’s success.

#3 Designing for CNC Machining

Effective design is crucial for successful CNC machining projects, influencing efficiency, quality, and cost. Creating detailed CAD models using tools like AutoCAD, SolidWorks, and Fusion 360 is essential, as these models provide precise specifications that guide the machining process, reducing errors and rework.

Adhering to Design for Manufacturability (DFM) principles further enhances efficiency by simplifying geometries, minimizing machining operations, and selecting easily machinable features. These design choices directly impact machining time, quality, and cost, with simplified designs reducing time and tool wear, and precise tolerances ensuring high-quality results without excessive rework.

#4 Tooling and Equipment Selection

Choosing the right tools and equipment is crucial for CNC machining projects to ensure efficiency and quality. When selecting CNC machines, factors such as capabilities (like cutting and milling), size compatibility with workpieces, and precision in achieving required tolerances must be considered. Common types include milling machines for shaping materials and turning machines for rotational operations.

Equally important is selecting the correct cutting tools, which significantly impact material removal rates, surface finishes, and dimensional accuracy. Proper tool materials, geometry, and maintenance are key to optimizing performance and extending tool life. Regular maintenance routines, including cleaning, sharpening, and timely replacement of worn tools, are essential for minimizing downtime and maintaining consistent machining quality throughout the project.

#5 Developing a Process Plan

Developing a thorough process plan is crucial for CNC machining projects to ensure efficiency and precision throughout the manufacturing process. Detailed planning clarifies the sequence of operations, tool requirements, and quality checks from initial setup to final finishing. Key steps include material preparation, CAD modeling, toolpath generation, and setup involving fixture design and tool selection.

Machining progresses through roughing, semi-finishing, and finishing stages to achieve precise dimensions and surface quality. Concurrently, establishing efficient workflows minimizes downtime and optimizes production flow, supported by realistic project schedules that account for complexities, resource availability, and deadlines. By adhering to a structured process plan and coordinated workflows, CNC machining projects can effectively meet quality standards and delivery timelines.

#6 Quality Control and Assurance

Quality control is pivotal in CNC machining to maintain precision and adhere to standards throughout production. Implementing rigorous quality control measures ensures that parts meet specifications and customer requirements, minimizing deviations and enhancing reliability. Techniques such as CNC machines and tool calibration uphold precision, while advanced metrology tools like coordinate measuring machines (CMMs) verify dimensional accuracy and surface finish.

Inspection involves dimensional checks against CAD specifications and assessments of surface texture for smoothness and functionality. Regular testing throughout production detects deviations early, facilitating adjustments to maintain consistency and high-quality standards. This comprehensive approach to quality control and assurance ensures that CNC machining projects deliver precise components that meet exacting specifications and customer satisfaction.

#7 Team Coordination and Communication

Effective team coordination and communication are essential for the success of CNC machining projects. Clear role assignment ensures accountability and efficiency by defining each team member’s responsibilities clearly, thereby minimizing overlaps and maximizing collaboration. Leadership roles, such as project managers or lead machinists, play a crucial role in coordinating tasks and resolving issues promptly to keep the project on track.

Tools like ERP systems and cloud-based collaboration platforms facilitate real-time communication and information sharing, centralizing project data and schedules for streamlined workflow. Regular team meetings with structured agendas ensure alignment on project progress, challenges, and adjustments, promoting agility and responsiveness to project needs. This systematic approach to team coordination and communication enhances productivity, minimizes errors, and contributes to the successful delivery of CNC machining projects.

Conclusion

In conclusion, careful planning and strategic preparation are fundamental to the success of any CNC machining project. By defining clear project scopes, setting achievable goals, and selecting suitable materials and equipment, teams can streamline operations and minimize costly delays. Detailed CAD modeling and design for manufacturability principles ensure efficient production processes and superior product quality.

Moreover, rigorous quality control measures and effective team coordination through clear role assignments and robust communication channels are pivotal in maintaining precision and meeting project timelines. Embracing these practices not only enhances project outcomes but also fosters a collaborative environment where innovation and efficiency thrive, ultimately leading to the delivery of exceptional results that meet or exceed client expectations.

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