Manufacturing Tool Design Guide
Tooling is fundamental to manufacturing processes. To transform raw materials into finished parts, manufacturers employ a combination of technology, skill, and appropriate tooling. But first, they’ll need a quality tool design to create the necessary equipment.
Without a proper tool design, your desired product would never scale up properly. Having the right manufacturing tooling improves the quality of finished parts while saving you significant amounts of time and money. The tooling design process is crucial in ensuring that the tools meet the specific requirements of the production line.
Throughout this article, we will discuss various basic aspects of tooling design including different tooling types, common tool design mistakes, and factors to consider when designing production tooling. Read on to see how you can effectively align tooling design to match your production needs.
What Is Manufacturing Tooling?
Manufacturing tooling refers to the different types of engineering tools used in the production of parts and components. They cut, form, or shape a raw material to create a desired part. The term ‘tooling’ can also refer to the process of designing and building the tools required for manufacturing. Tooling design considerations are crucial in determining the efficiency and effectiveness of these tools.
There are different classifications of tooling, each with unique features and applications. They include;
Soft tooling refers to less durable tools that are typically used in prototyping and short production runs. An example of a soft tool material is silicon or fiberglass.
Hard tooling offers robustness and is ideal for high-volume production. These tools are made from durable materials such as steel or nickel alloys.
Prototype tooling is the process of developing prototype tools. This step allows tooling engineers to troubleshoot, improve, and validate the tool design.
Bridge tooling is also known as pilot tooling or development tooling. It essentially bridges the gap between prototyping and production tooling. This fast and cost-effective process is typically used for initial production orders.
Production tooling is the final, high-volume stage of tooling. It is used to create robust, high-precision tools for mass production of parts and components.
Why is Tool Design Important in Manufacturing?
The success of any manufacturing process hinges on having the right tools. Tooling design ensures that manufacturers can transform raw materials into finished goods with accuracy, cost-effectiveness, and consistency.
Manufacturing process operations:
Tooling design principles are an essential part of manufacturing operations. Simply put, you need to have the relevant tools to produce parts. This is the case whether you’re manufacturing something as simple as a pin or very complex geometries such as aerospace components.
Enhanced Product Quality:
High-quality tooling translates to high-quality parts. Proper design ensures that production tooling is created to exact specifications. In turn, precise tools are essential in manufacturing accurate components. As an example, a defective injection mold will always produce flawed parts. On the other hand, a precision-machined mold allows you to match the parts’ desired features perfectly.
Adhering to tooling design standards is crucial to achieving these high-quality results.
Increased Manufacturing Efficiency:
Effective tooling allows manufacturers to streamline production workflows, lower lead times, reduce costs, and minimize waste. Good tooling also eliminates common errors that can be time-consuming and costly to correct. This is especially beneficial during mass production where small savings can quickly add up through tooling design optimization.
Key Considerations in Tooling Design
Multiple factors come into play when designing tooling in manufacturing. To avoid costly production errors, the manufacturing provider will work with tooling engineers and product designers to create the best possible tool design. This process involves assessing graphical designs meticulously and correcting potential flaws before production. Here are some of the critical considerations in production tooling design. Following tooling design guidelines can help streamline this process and ensure optimal results.
1. Tooling Material
Tooling material selection is one of the most important factors to consider during tool design. So, what is the ideal tool material? Well, it varies depending on the application. For example, aluminum injection molds are excellent for creating plastic parts.
However, aluminum is not a suitable material for CNC milling cutters since it lacks adequate strength and hardness. High-speed steels and carbide tools are stronger and offer better performance as machining tools. They are capable of withstanding repeated stress and boast a longer tool life.
When choosing the tooling raw material, you want to select the option that offers the best performance, at the lowest cost, and in the least amount of time. Here are some questions to help you determine the perfect tooling material for your project.
- What tasks do you need the tool to execute?
- How many parts will the tool produce?
- What is the expected tool life?
- What level of precision is required?
2. Production Volume and Durability
The volume of production also impacts tooling design and tooling durability. Mass production and small-volume manufacturing have different tooling requirements. If you’re creating a large number of parts, you need a robust tool that can withstand a significant production run. In such scenarios, you can opt for tools made from durable metals that are capable of enduring repeated stress without deformation. Long-lasting tools can be costly to produce. However, they save you the cost and hassle of making several tools for a single production run.
For example, let’s say a high-speed steel tool is capable of machining 10,000 units in its lifetime. On the other hand, a carbide tool has the capacity to machine 60,000 units and it increases the cutting speed by 40%. While the carbide tool has a higher initial cost, it may be more suitable for mass-produced parts. However, high-speed steel would be a better option if you require fewer components.
3. Tolerance and Precision
Different manufactured parts require different levels of precision tooling. For instance, medical, automotive, and aerospace components must be very accurate. Even the slightest deviations can prove disastrous.
On the other hand, some applications are more lax and, therefore, looser tolerances are acceptable. The manufacturer will require a precise production tool to achieve tight tolerances. Such tools tend to be more costly to create and they require regular replacement and/or maintenance. Well-made tools will generally last longer and provide more value.
4. Cycle Times
Tooling cycle time refers to the amount of time it takes to transform a raw material into the final product. If a pressure die-casting mold produces 6 parts every hour, its cycle time would be 6 minutes. One way of reducing the production time is to increase the processing speed. However, this puts more pressure on the tool, generates more heat, and can lead to premature wearing out or even tool failure in extreme cases.
Manufacturers can simultaneously increase the processing speed and tool longevity by applying an aftermarket thin film coating on the tool. Chrome plating and nickel plating are common surface coatings used to enhance tool performance and durability. The added expense of these protective coatings is weighed out against the higher productivity rate.
5. Cost-effectiveness
The expenses incurred in designing, producing, and maintaining tooling in manufacturing are known as tooling costs. Conducting a tooling cost analysis is essential to understand these expenses. They affect the overall production cost of an item and hence the suitable pricing. Generally, manufacturers strive to create high-quality goods while keeping production costs low. This ensures profitability and allows them to remain competitive.
Tooling costs can make or break a business. High production costs cut into the profit margins leading to lower revenue. Therefore, it’s crucial to analyze the costs versus benefits associated with a particular manufacturing tooling before starting the production process.
Types Of Manufacturing Tools
Different manufacturing processes require different tooling types. These tools fall under the following main categories.
1. Cutting tools
Cutting tool design is crucial in machining processes to slice or remove material from a workpiece and create the desired shape. This process can be done manually using hand-held tools such as hack saws, metal shears, and angle grinders. Alternatively, you can opt for CNC machining where computer software guides the movements of the cutting tool. Cutting tools are designed to withstand friction and high temperatures, especially in high-speed machining. Examples of machine tooling include end mills, drill bits, fly cutters, shapers, grinding wheels, and planers.
2. Dies
Die design is another essential tool in the manufacturing industry. These specialized machine tools are used for cutting and/or forming materials into the desired profile. Dies are typically customized to create parts of a specific size and shape. Therefore, custom die casting offers more cost-effectiveness when used in the high-volume production of parts. The common types of dies include simple dies, compound dies, progressive dies, combination dies, round split dies, transfer dies, and multiple dies.
3. Injection molds
Injection molding is a production process that creates parts by injecting molten material into a mold cavity. As the material cools and solidifies, it takes the shape of the mold. The quality of injection molded parts is highly dependent on the mold design. Therefore, manufacturers usually take the time to machine highly precise molds before part production. These tools can be used over and over, and they are capable of mass-producing identical parts. While the initial tooling costs may be high, injection molding typically has a lower long-term cost per unit.
4. Workholding tools
Workholding design refers to any devices that are used to secure the workpiece in place during production processes. While the focus tends to be on other components of the machining process, such as the CNC machine and the cutting tools, the importance of workholding cannot be overlooked. These tools prevent unwanted movement, ensuring precise and efficient machining. They include clamps, vices, chucks, fixtures, jigs, locators, collets, mandrels, end stops, and pallets.
Basic features of a Manufacturing tool
Cavity half :
This is the stationary side of a tool, crucial for effective cavity design. It is usually attached to the side of the molding machine and remains fixed during the molding process.
Core half :
Unlike the cavity half, the core half refers to the movable side of a tool, which is a crucial aspect of its core design. It’s capable of opening and closing allowing for the removal of finished parts.
Cooling lines:
As the name suggests, cooling lines are channels that are machined into tooling as part of an effective cooling system design to facilitate the flow of coolant. They facilitate cooling during manufacturing processes preventing defects such as sink marks and warping.
Ejector system:
The ejector design is an essential component that is responsible for removing completed parts from mold and dies. Ejector pins are designed to efficiently extract parts without causing damage.
Ejector system:
The ejector design is an essential component that is responsible for removing completed parts from mold and dies. Ejector pins are designed to efficiently extract parts without causing damage.
Side actions:
Side action design involves the use of inserts added to a mold to facilitate the creation of undercut geometries. They are crucial for intricate part designs and enable the production of parts that could not otherwise be made using a straight-pull mold.
Tooling design errors and how to optimize them
Here are some of the most common tooling design errors in production.
Non-Uniform Walls:
Wall thickness design is crucial because different wall thicknesses lead to different cooling rates. The thin sections will typically cool faster than their thicker counterparts. This can create stresses at the boundaries of the thin and thick sections leading to warping, deformation, and even cracks in the manufactured parts.
Not Leveraging Drafts:
Manufacturing processes such as die casting and injection molding rely on draft angle design to effectively remove the finished part from the mold. If the tool lacks a taper or the draft angle is too small, attempting to remove the part from the mold can lead to damage and cosmetic defects known as drag marks. Tooling engineers and designers can determine a suitable draft angle before production to facilitate the seamless ejection of parts.
Leaving many Sharp Corners:
Manufacturers tend to avoid sharp corners in corner design whenever possible and for good reason. First, these features tend to be costly to machine. Secondly, sharp corners cause undue strain on the cutter blades increasing the risk of breakage. Lastly, adding sharp corners to injection molded parts creates areas of high-stress concentration that are susceptible to failure. An easy design solution would be to replace sharp corners with radiused corners or incorporate features such as undercuts.
Author
Gavin Leo is a technical writer at Aria with 8 years of experience in Engineering, He proficient in machining characteristics and surface finish process of various materials. and participated in the development of more than 100complex injection molding and CNC machining projects. He is passionate about sharing his knowledge and experience.