5.3 Tooling and fixturing for subtractive manufacturing
5 min read•august 15, 2024
Tooling and fixturing are crucial for successful subtractive manufacturing. They ensure accuracy, quality, and safety when creating prototypes. Proper tools and fixtures boost efficiency, reduce errors, and allow for complex designs.
Choosing the right tools and fixtures depends on the material, design, and production needs. Single-point tools work for lathes, while multi-point tools are great for . Specialized tools handle unique tasks. The right setup can make or break your project.
Tooling and Fixturing Importance
Critical Factors for Manufacturing Success
Top images from around the web for Critical Factors for Manufacturing Success
Production and Operations Management—An Overview | OpenStax Intro to Business View original
Is this image relevant?
Shah9il's Blog: Enlist the areas of CSF method in internal environment analysis. View original
Is this image relevant?
MLab in the Humanities » University of Victoria » Subtractive Manufacturing and the Kits View original
Is this image relevant?
Production and Operations Management—An Overview | OpenStax Intro to Business View original
Is this image relevant?
Shah9il's Blog: Enlist the areas of CSF method in internal environment analysis. View original
Is this image relevant?
1 of 3
Top images from around the web for Critical Factors for Manufacturing Success
Production and Operations Management—An Overview | OpenStax Intro to Business View original
Is this image relevant?
Shah9il's Blog: Enlist the areas of CSF method in internal environment analysis. View original
Is this image relevant?
MLab in the Humanities » University of Victoria » Subtractive Manufacturing and the Kits View original
Is this image relevant?
Production and Operations Management—An Overview | OpenStax Intro to Business View original
Is this image relevant?
Shah9il's Blog: Enlist the areas of CSF method in internal environment analysis. View original
Is this image relevant?
1 of 3
Proper tooling and fixturing achieve dimensional accuracy, surface finish quality, and overall part integrity in subtractive manufacturing processes
Impact machining efficiency, productivity, and cost-effectiveness by reducing setup time and minimizing errors
Contribute to operator safety by securely holding the workpiece and minimizing the risk of accidents during machining operations (reduced tool breakage, fewer loose parts)
Directly influence achievable tolerances and complexity of features in the final prototype (tighter tolerances, intricate geometries)
Consequences of Improper Tooling and Fixturing
Lead to workpiece deformation, resulting in out-of-spec parts
Cause tool breakage, increasing production costs and downtime
Produce poor surface finish, requiring additional post-processing
Increase scrap rates, wasting materials and resources
Compromise operator safety due to unstable workpiece holding
Cutting Tool Types and Applications
Single-Point Cutting Tools
Used in lathe operations for facing, , and boring applications
Include turning tools and boring bars
Characterized by a single cutting edge engaging the workpiece
Examples:
External turning tools for cylindrical surface generation
Internal boring bars for creating or enlarging holes
Threading tools for cutting external or internal threads
Multi-Point Cutting Tools
Employed in milling and drilling operations for creating complex geometries and features
Include end mills, face mills, and drill bits
Feature multiple cutting edges that engage the workpiece simultaneously
Examples:
End mills for slot cutting, profiling, and pocket milling
Face mills for creating flat surfaces on large workpieces
Drill bits for producing holes of various diameters
Specialized Cutting Tools
Used for specific finishing operations and creating internal features with high precision
Include reamers, taps, and broaches
Designed for particular machining tasks that require tight tolerances or unique geometries
Examples:
Reamers for producing precise hole diameters and smooth surface finishes
Taps for cutting internal threads in pre-drilled holes
Broaches for creating internal keyways or splines
Tool Materials and Coatings
Tool materials range from (HSS) to and
Offer different levels of hardness, wear resistance, and heat
HSS suitable for low-speed applications, carbide for high-speed machining
Coatings enhance tool performance:
(TiN) improves wear resistance and reduces friction
(DLC) provides excellent hardness and low friction
(Al2O3) offers thermal insulation for high-speed cutting
Cutting Tool Geometry
Selection of geometry crucial for optimizing chip formation, surface finish, and tool life
Key geometric parameters:
affects chip formation and cutting forces
prevents rubbing between tool and workpiece
influences surface finish and tool strength
Geometry optimization based on workpiece material and machining conditions
Workpiece Fixturing Principles
Fundamental Fixturing Concepts
Workpiece fixturing securely holds the part in a precise position and orientation during machining
Ensures accuracy and repeatability in manufacturing processes
of fixturing constrains workpiece in all six degrees of freedom
Uses combination of locating and clamping elements
Three points constrain primary plane, two points constrain secondary plane, one point constrains tertiary plane
Common Fixturing Devices
Vises provide quick and versatile clamping for prismatic parts
offer concentric gripping for cylindrical workpieces
Collets provide precise and uniform clamping for round or polygonal parts
Dedicated fixtures designed for specific part geometries or high-volume production
Modular fixturing systems utilize standardized components to create custom setups
Offer flexibility for prototyping and small-batch production
Allow rapid reconfiguration for different part designs
Advanced Fixturing Techniques
techniques employed for thin or delicate workpieces
Distribute holding forces evenly across the part surface
Minimize part distortion and allow machining of entire surface
Magnetic chucks offer rapid setup for ferromagnetic materials
Provide uniform clamping force distribution
Suitable for large, flat workpieces or multiple small parts
Hydraulic clamping systems offer precise and repeatable clamping forces
Allow remote operation and automation of fixturing process
Provide consistent clamping pressure across multiple points
Fixturing Considerations
Workpiece deformation during fixturing must be minimized
Especially critical for thin-walled or compliant parts
Proper support and distributed clamping forces maintain dimensional accuracy
Fixturing must accommodate tool access to all required surfaces
Consider clearance for cutting tools, tool holders, and machine components
May require multiple setups or specialized fixture designs for complex parts
Tooling Selection for Prototypes
Material-Based Considerations
Material properties influence selection of cutting tools, tool geometries, and machining parameters
Hardness affects tool material choice (HSS for soft materials, carbide for harder materials)
Ductility impacts chip formation and required tool geometries
Thermal conductivity influences cutting speeds and cooling requirements
Design Complexity and Requirements
Prototype design complexity dictates choice of cutting tools and fixturing methods
Feature sizes determine tool diameters and geometries
Tolerances influence tool selection and fixturing precision
Surface finish requirements impact tool selection and cutting parameters
Production Factors
Production volume and batch size affect tooling and fixturing decisions
General-purpose tooling for low-volume prototypes
Dedicated or custom solutions for improved efficiency in higher volumes
Machine tool capabilities influence tooling and fixturing selection
Power and rigidity determine suitable cutting tools and parameters
Available tool interfaces (e.g., HSK, CAT, BT) limit tooling options
Economic and Practical Considerations
Cost factors impact tooling and fixturing approach:
Initial tooling investment balanced against expected production volume
Tool life considerations for optimal cost-effectiveness
Setup time reduction through appropriate fixturing methods
Consider fixturing methods that allow access for post-processing
Key Terms to Review (39)
3-2-1 principle: The 3-2-1 principle is a guiding rule in tooling and fixturing that ensures precise and repeatable positioning of a workpiece during subtractive manufacturing processes. It specifies that a workpiece should be supported and located using three points of contact to establish a stable base, two points to control the horizontal movement, and one point for vertical positioning. This approach minimizes errors caused by misalignment, ensuring consistency in the manufacturing process.
Adaptive Machining: Adaptive machining refers to the technique of adjusting machining processes in real-time based on feedback and sensor data to optimize performance and accuracy. This method enables machines to automatically modify their parameters, such as feed rate and cutting speed, to suit the varying conditions of the material being machined, leading to enhanced efficiency and reduced tool wear.
Aluminum alloy: An aluminum alloy is a mixture of aluminum with other elements, which enhances its properties such as strength, corrosion resistance, and machinability. These alloys are widely used in manufacturing processes because they combine lightweight characteristics with improved mechanical performance, making them ideal for various applications including aerospace, automotive, and tooling.
Aluminum oxide: Aluminum oxide is a chemical compound of aluminum and oxygen, represented by the formula Al$_2$O$_3$. This compound is commonly used in various applications, particularly in tooling and fixturing for subtractive manufacturing due to its hardness and durability, making it an ideal material for cutting tools and abrasive products.
ANSI Standards: ANSI standards are a set of guidelines and specifications developed by the American National Standards Institute to ensure consistency, safety, and quality in various industries, including manufacturing. These standards help streamline processes and improve communication among manufacturers, suppliers, and consumers by providing a common framework for measurement and design. In the context of tooling and fixturing for subtractive manufacturing, ANSI standards play a critical role in ensuring that tools and fixtures are compatible, safe to use, and capable of producing precise components.
Broach: A broach is a cutting tool used in manufacturing to create precise shapes and features on a workpiece through a process called broaching. This tool is essential in subtractive manufacturing, as it allows for the efficient machining of complex profiles and holes with high accuracy and surface finish. Broaching can be performed either vertically or horizontally, depending on the application, and is often used for making internal features such as keyways and splines.
Carbide: Carbide is a compound made of carbon and a less electronegative element, most commonly used in cutting tools and industrial applications due to its exceptional hardness and durability. Its properties make it an ideal material for tooling and fixturing in subtractive manufacturing processes, as it can withstand high temperatures and resist wear during machining operations.
Ceramics: Ceramics are inorganic, non-metallic materials that are typically made from compounds of a metallic and a non-metallic element. These materials are known for their high hardness, thermal stability, and resistance to chemical corrosion, making them suitable for various applications in tooling and fixturing. Their ability to withstand high temperatures also makes them a valuable choice in subtractive manufacturing processes, where heat and wear can be significant challenges.
Chuck Jaws: Chuck jaws are the gripping mechanisms used in lathe chucks to hold workpieces securely during machining operations. They come in various configurations, such as three-jaw and four-jaw designs, which enable precise clamping and centering of different shapes and sizes of materials. The functionality of chuck jaws is crucial for ensuring accuracy and stability in subtractive manufacturing processes.
Clamping Fixture: A clamping fixture is a specialized tool used in subtractive manufacturing to securely hold and position workpieces during machining processes. It ensures precise alignment and stability, allowing for accurate machining while preventing movement that could lead to errors or damage. Clamping fixtures are essential for maintaining the integrity of the workpiece and achieving consistent results in manufacturing operations.
Clearance Angle: The clearance angle is the angle between the cutting edge of a tool and the surface of the workpiece that allows for proper material removal without excessive friction. This angle is crucial in subtractive manufacturing as it directly affects tool performance, wear, and the quality of the finished product. A well-designed clearance angle ensures efficient cutting action and minimizes the chances of tool binding or damage during the machining process.
Collet: A collet is a specialized tool holder designed to securely grip and hold a workpiece or tool in place during machining processes. It provides a precise clamping mechanism that ensures stability and accuracy, which is crucial for subtractive manufacturing applications. Collets are often used with milling machines, lathes, and other machining equipment to achieve high precision in cutting and shaping materials.
Diamond-like carbon: Diamond-like carbon (DLC) is a form of carbon that exhibits properties similar to those of diamond, such as high hardness, low friction, and excellent wear resistance. It is often used as a coating material due to its unique combination of mechanical and chemical properties, making it suitable for various applications in tooling and fixturing.
End mill: An end mill is a cutting tool used in milling machines to remove material from a workpiece through rotational movement. It typically features a cylindrical shape with multiple cutting edges on its end and sides, allowing for versatile operations such as slotting, drilling, and contouring. The design of an end mill allows it to efficiently cut in both vertical and horizontal directions, making it an essential tool in subtractive manufacturing processes.
Fixture plate: A fixture plate is a type of tooling component used in subtractive manufacturing that provides a stable and precise surface for securing workpieces during machining operations. This essential piece of equipment helps to ensure that parts are held securely in place, allowing for accurate machining, reducing errors, and improving overall production efficiency. Fixture plates can be customized with various features such as locating pins, T-slots, or threaded holes to accommodate different workpieces and setups.
Gage blocks: Gage blocks, also known as gage blocks or slip gauges, are precision measuring tools used to establish accurate lengths and thicknesses. They are made from high-grade steel or ceramic and are designed to be stacked together to create various lengths with extreme accuracy, essential for achieving precise measurements in manufacturing processes.
High-speed steel: High-speed steel (HSS) is a tool steel that maintains its hardness and strength at high temperatures, making it ideal for cutting tools. Its unique composition typically includes tungsten, molybdenum, chromium, and vanadium, which enhances its wear resistance and toughness. This allows high-speed steel to perform well in machining processes where heat generation is significant, especially in subtractive manufacturing.
Hydraulic clamping system: A hydraulic clamping system uses pressurized fluid to create strong, adjustable forces that hold workpieces securely in place during machining processes. This system is crucial for ensuring precision and stability in subtractive manufacturing by evenly distributing clamping pressure and reducing the risk of movement or vibration while cutting. The ability to easily adjust the clamping force makes it a versatile choice in various manufacturing applications.
ISO 9001: ISO 9001 is an internationally recognized standard that outlines the requirements for a quality management system (QMS). It helps organizations ensure they meet customer and regulatory requirements while continuously improving their processes. By implementing ISO 9001, companies can enhance their operational efficiency, increase customer satisfaction, and establish a culture of quality, which can be particularly relevant in areas such as risk management, production processes, and material selection.
Lathe tool: A lathe tool is a cutting instrument used in a lathe machine to shape and cut material, typically metal or wood, by rotating the workpiece against the stationary cutting edge. This tool is crucial for achieving precise dimensions and surface finishes during the subtractive manufacturing process, where material is removed from a solid block to create the desired shape.
Magnetic chuck: A magnetic chuck is a specialized tool used in machining processes to securely hold ferromagnetic workpieces in place during cutting or milling operations. By using a magnetic field, these chucks provide a strong grip on the material, allowing for precise machining while ensuring that the workpiece remains stable and accurately positioned throughout the process. This type of chuck is particularly beneficial in subtractive manufacturing, as it minimizes setup time and improves the overall efficiency of machining operations.
Milling: Milling is a subtractive manufacturing process that involves the removal of material from a workpiece using rotating cutting tools. This technique allows for the precise shaping of materials such as metal, plastic, and wood, making it essential for creating complex parts and components in various industries. By manipulating the movement of the tool and the workpiece, milling can achieve intricate designs and fine tolerances.
Modular fixturing system: A modular fixturing system is a versatile assembly of components designed to securely hold and position workpieces during manufacturing processes, particularly in subtractive manufacturing. These systems enable rapid setup changes and reconfiguration, making them ideal for diverse production needs while enhancing efficiency and reducing downtime.
Multi-point cutting tool: A multi-point cutting tool is a type of cutting tool that has multiple edges or points which actively participate in the cutting process. These tools are designed to efficiently remove material from a workpiece during machining operations by distributing the cutting forces over several edges, resulting in a smoother finish and increased tool life. Common examples include milling cutters, drill bits, and broaches, which are crucial in subtractive manufacturing for producing complex shapes and achieving precise dimensions.
Nose radius: Nose radius refers to the rounded edge or curvature at the tip of a cutting tool, which plays a significant role in the tool's performance during machining operations. A properly designed nose radius helps in controlling the cutting action, improving surface finish, and minimizing tool wear. The size and shape of the nose radius can affect the strength and rigidity of the cutting tool, making it essential for effective subtractive manufacturing.
Rake Angle: Rake angle is the angle formed between the cutting edge of a tool and a reference plane, typically the surface of the workpiece being machined. It plays a vital role in the cutting process as it influences the flow of material during cutting, affects chip formation, and impacts tool wear. A proper rake angle can enhance cutting efficiency, reduce cutting forces, and improve surface finish.
Reamer: A reamer is a cutting tool used in machining processes to enlarge and finish existing holes to precise dimensions and improve surface finish. Reamers are essential in subtractive manufacturing for achieving tighter tolerances and better surface quality compared to standard drilling operations, ensuring that components fit together correctly and function as intended.
Single-point cutting tool: A single-point cutting tool is a type of cutting tool used in machining processes where the tool has one main cutting edge that removes material from the workpiece. This tool is primarily used in turning operations on lathes, where it shapes and sizes the workpiece by removing excess material. Its simple design allows for efficient cutting and is essential in subtractive manufacturing, making it a key component in various machining applications.
Specialized cutting tool: A specialized cutting tool is a precision instrument designed to remove material from a workpiece during the manufacturing process, often tailored for specific tasks or materials. These tools are essential for achieving high accuracy and efficiency in subtractive manufacturing, allowing for complex shapes and intricate designs that standard tools may not accomplish. They can be made from various materials and can take numerous forms, such as drills, mills, or lathes, depending on the requirements of the task.
Tap: A tap is a cutting tool used to create internal threads in a hole, allowing for the insertion of screws or bolts. Taps are essential in mechanical prototyping because they help ensure that components can be securely fastened together, which is crucial for the integrity and functionality of assembled parts. By accurately forming threads, taps enable the effective transfer of loads and stresses between components, enhancing the overall strength and durability of a design.
Titanium nitride: Titanium nitride is a hard, ceramic material formed from titanium and nitrogen, commonly used as a coating to enhance the performance and durability of cutting tools and various components in subtractive manufacturing. This material is valued for its exceptional hardness, wear resistance, and ability to withstand high temperatures, making it an ideal choice for tooling and fixturing applications.
Tolerance: Tolerance refers to the permissible limit or limits of variation in a physical dimension or measured value. It plays a crucial role in engineering and manufacturing, as it defines how much deviation is acceptable in the production of parts and assemblies to ensure functionality and fit. A clear understanding of tolerance is essential for maintaining dimensional accuracy, ensuring compatibility between components, and optimizing processes in both subtractive manufacturing and CNC machining.
Tool Holder: A tool holder is a device used to securely clamp and hold cutting tools in place during machining operations. It is essential in ensuring precise alignment and stability, which are critical for achieving accurate cuts and maintaining the integrity of the workpiece. Tool holders come in various types and configurations to accommodate different tools and machining processes, making them a fundamental component in subtractive manufacturing.
Toolpath optimization: Toolpath optimization refers to the process of planning and improving the movement of a cutting tool during subtractive manufacturing processes to enhance efficiency, reduce cycle time, and improve part accuracy. This involves analyzing the path that the tool will take to remove material from a workpiece while considering factors such as speed, feed rates, and the overall layout of the machining operations. Proper toolpath optimization is crucial for maximizing productivity and minimizing wear on tools.
Turning: Turning is a machining process where a cutting tool removes material from the surface of a rotating workpiece to create cylindrical shapes or features. This process is essential in producing precise components, and it connects with various aspects of tooling and fixturing, ensuring parts are held securely during machining to achieve desired tolerances and finishes.
Vacuum fixturing: Vacuum fixturing is a technique used in manufacturing where a vacuum is created to hold a workpiece securely against a surface during machining processes. This method provides a strong, even hold on irregularly shaped or delicate materials, ensuring precision and stability while reducing the need for traditional clamps or mechanical fixtures. It's especially useful in subtractive manufacturing as it can accommodate complex geometries and help avoid damage to the workpiece.
Vise: A vise is a mechanical device used to securely hold an object in place while work is performed on it, typically featuring two parallel jaws that can be adjusted to accommodate different sizes of materials. Vises are essential in subtractive manufacturing processes as they provide stability and precision when cutting, shaping, or machining materials. They are commonly used in workshops and factories to ensure that parts remain stationary during operations such as drilling or milling.
Workholding: Workholding refers to the methods and devices used to securely hold a workpiece in place during manufacturing processes, particularly in subtractive manufacturing. Effective workholding is crucial for achieving precision, accuracy, and safety while machining or shaping materials. It ensures that the workpiece remains stable and properly aligned throughout the operation, minimizing the risk of errors and enhancing overall productivity.
Zero-point clamping: Zero-point clamping is a precision workholding system used in manufacturing that allows for rapid and accurate positioning of workpieces on a machine tool. This system utilizes predefined reference points to align the workpiece, ensuring consistent repeatability and reducing setup times. It plays a critical role in enhancing productivity and accuracy in subtractive manufacturing processes by minimizing human error during setup.