Posted on Nov. 22th, 2019, | By Project Manager, Mandy
In the increasingly fierce market competition environment, how to effectively reduce costs and optimize costs have become one of the focuses of enhancing the competitiveness of enterprises in all walks of life. In the way of cost reduction, DFM has the greatest impact on product cost due to the simplification and assemblability of the design in the early stage of new product design. On the other hand, for mass-produced products, in order to achieve cost reduction, companies also pay attention to how DFM chooses the best process and materials, and understand the cost of component suppliers to determine a reasonable price range.
What is DFM?
The term DFM stands for "manufacturable design." It describes the process of designing or designing a product to facilitate manufacturing, allowing for the repair of potential problems during the design phase, which is the cheapest place to solve these problems. This can be achieved by optimizing and simplifying product design. Therefore, it is a very effective method and is used by large companies around the world.
Shorten the development cycle
Finding problems and correcting them in the design process can avoid time waste caused by repeated wear and tear between departments and manufacturers, reduce engineers' verification time and improve error time, and deliver designs faster. Save 50% on product launch time.
(1) Reduce the number of changes to the version or eliminate the need to modify the design and reduce development costs. Products that are not controlled by the DFM specification often find problems in the later stages of product development or in mass production. Changes at this time undoubtedly increase development costs.
(2) Reduce rework and repair costs.
(3) Reduce the introduction cost of new processes and reduce the huge cost of process development.
Improve product quality and reliability
Once the product is produced successfully, it can improve product quality and reputation.
Conducive to technology transfer and streamline product transfer process
Products with good manufacturability can be smoothly transferred to OEM/CM for smooth technology transfer and transition.
Conducive to the standardization of the processing technology
DFM is a standard for manufacturing, and it is a good bridge for internal and external prayer. It links the design, manufacturing, and product-related departments organically, and everyone can effectively follow the code.
Establish communication standards
There are standards to follow, which can greatly improve work efficiency.
Respond quickly to customer needs
Establish design and quality standards for communication with customers, respond to customer design changes in a timely manner, and shorten new product introduction time.
How to combine DFM with CNC process?
1. Choose a manufacturing process
The production of DFM should be based on different designs and different manufacturing. The manufacturing process common in the product prototype stage and small batch production stage is CNC. How do we better specify DFM in the CNC process? Mainly from the following steps to carry out work.
The next step in confirming the manufacturing process is the design of the product. Product design is compatible with the manufacturing process.
CNC machining is a material reduction process, and the time to remove material is a major factor in determining the cost of machining. The machining time is determined by the volume and shape of the milling material and the speed of the tool. When a milling cutter is used, the strength and stiffness of the tool, determined in part by the length to diameter ratio of the tool, will be most effective in determining the speed. The shorter the tool is relative to its diameter, the faster it can pass through the material.
It is also important to choose the right material. Plastics are common materials, and some increase glass fiber to increase the hardness of the material, but most are easier to process. Among the metal materials, aluminum, brass and soft metals are easier to process. For steels, titanium and other solid materials, it is more difficult to process with increasing hardness and takes longer. Therefore, the choice of materials should consider the following factors: mechanical properties, such as the strength of the final product, optical properties, such as reflection or transparency, thermal properties and end product resistance to prevent high temperatures and high temperatures.
Another factor influencing processing costs is tolerance. The more stringent geometric tolerances required on the drawings, the higher the processing costs of the components. Therefore, in the design, the appropriate tolerance zone should be designed without affecting the assembly function.
DFM case studies
Sharp internal corners
One of the DFM guidelines is to avoid the use of sharp internal angles when designing machined parts. The CNC tools are round, which is the milling force generated by the rotation. It is impossible to achieve a 90° angle at the corner. Therefore, verify that there are any internal sharp corners during the audit design process. If not stated otherwise in the technical drawings, it is recommended that any detected sharp internal angles on the part be machined to a 2 mm radius to minimize manufacturing costs. If you want to achieve these sharp internal angles, the common method is EDM or wire cutting, but they are expensive.
EDM, also known as Electrical Discharge Machining, relies on electricity to corrode work rather than the actual "cutting" tool. The disadvantage of EDM is that it works very slowly, especially when compared to CNC cutting tools. This means that wire cutting operations have considerable potential.
Wire cutting is often used for metal plates or sheets, two-dimensional structures. This is also a very economical solution for getting a square. Even the square corners are not perfect because the diameter and the slit of the laser are slightly larger than the laser.
The main disadvantages of laser cutting are surface finish and precision. Although it is usually possible to obtain +/- 0.005 on a 1/4" thick steel plate, you will find that the surface finish is much rougher than the machined surface.
Different wall thicknesses determine the time of the cutting process,therefore, it is recommended to update the appropriate material thickness to reduce costs.
Thickness may be non-machineable because these features may break during manufacturing due to cutting forces. For CNC machining, the recommended minimum wall thickness is 0.8 mm for metal and 1.5 mm for plastic.
In an increasingly competitive world, product design and customer service may be the ultimate way to differentiate a company's capabilities. As product design becomes more important, the concept of manufacturability design and integrated product development will be critical. By integrating the synergies of product and process design to efficiently manufacture high-quality, high-performance products, this will be the key to achieving and maintaining a competitive advantage.
With 10 over years' exprience of prototyping business, Wayken has made numerous of quality engineering prototype & prototypes for clients throughout the world. If you are a designer or manufacturing engineer with the problem of how to improve the manufacturability of parts, pls feel be contact us.