Laying A Good Foundation for Machining Can Improve Machining Accuracy
Knowledge

Laying A Good Foundation for Machining Can Improve Machining Accuracy

Machining is one of the most important cutting process used in any manufacturing industry. There are many different processing methods and each of these methods may require the use many different cutting tools. With each tool corresponding to a different cutting process, often problems can occur which not only affect the machining accuracy, but also the quality of the workpiece, and can even cause accidents. Understanding the cutting processes, machine tools used, and factors affecting accuracy are important for avoiding problems. Understanding the basics of cutting processing and smart tools will make your machining more effective and require less effort.
Published: Apr 13, 2022
Laying A Good Foundation for Machining Can Improve Machining Accuracy

What Is Machining?

Machining refers to the procedure of using some sort of tool to remove material from a workpiece to give the material the desired shape. There are two general categories of processing which machining can be divided into; milling and turning. Milling is the process where the workpiece is held in a fixed position and a tool is moved to remove material from the workpiece. Turning is where the workpiece is rotated, and the tool maintains a set position to cut the workpiece as it rotates. 

Some cutting processes such as turning, drilling, broaching, etc. will use tools with single blades, while other procedures such as cutting, grinding, and polishing often use tools with several blades. Various types of abrasive tools are used for grinding processes.  By selecting the most appropriate tools for the processing required, a broad range of products can be manufactured with high precision and low surface roughness for a broad range of applications.

During machining, the temperature of the workpiece may be regulated to obtained a desired effect on the workpiece. When machining is performed at ambient temperature it is called cold processing.  Hot processing is when the work is done at a temperature higher than ambient temperature. This is usually done when some form of chemical reaction is desired in order to change the properties of the workpiece material such as for hardening the workpiece. 


Machine Tools:

Machine tools come in many designs and are produced to meet to various specifications. Many current machine tools are digitized to meet set specifications according to international standards. By being familiar with these standards you can choose machine tools that will achieve the best results for your machining needs. Some manufacturers will improve on technology and develop their own specialty tools to face market competition. When operators are familiar with the tool options available, they can adapt their machine parameters to achieve high-precision machining.

Factors Affecting Machining Accuracy

  1. Many parameters need to be maintained in order to maintain quality of production. Compromised quality in the workpiece can result from errors in the machining tools. Spindle rotation error, guide rail error, and transmission chain error are problems that can occur as a result of improper installation or from wear on a machine tool over time. All these will affect manufacturing efficiency and accuracy of the workpiece to be processed.
  2. The external force of the machine tool: When a force is applied to an object, the object will generate a force that resists deformation, which is called rigidity. To perform high-precision processing, the rigidity of the machine tool is important. The more rigid the machine tool, the higher the dynamic precision. The rigidity of the machine tool itself as well as the rigidity of the workpiece needs to be considered. The rigidity of the machine tool will mainly depends on its material, cross-sectional shape, size, etc., while the rigidity of the workpiece material, will depend on its geometric size, hardness, processing method, and surface roughness.
  3. Thermal deformation: The object will expand with the change of temperature, and the degree of change from heating will vary with different materials. Therefore, it is necessary to pay attention to the change in temperature during processing and understand the relationship between the operating time and temperature of the machine tool and workpiece.
  4. Use of cutting fluid: Cutting fluid is important for machine tools. It can provide effective protection for workpieces and tools, reduce tool wear and improve the machining accuracy of workpieces.
  5.  Influence of speed: Under normal circumstances, the higher the cutting speed, the higher the efficiency, but it will be restricted by the hardness, plasticity, carbon content, tool hardness, and geometric properties of the workpiece. Therefore, the speed should be adjusted according to the tool and workpiece material to ensure machining accuracy.


Milling Machine Processing:

Milling Machine Processing is any of the procedures performed on a workpiece using some form of cutting tool attached to a rotating shaft. The tool intermittently contacts and cuts the workpiece to machine the surface of the workpiece into a flat or curved surface. Other various operations can be performed such as drilling and grooving. Milling machines can be divided into horizontal and vertical types according to the spindle direction of the tool. One type of machine called a gantry-type milling machine has a structure that straddles a horizontal long-bed and can simultaneously machine with multiple cutters.  

  • General purpose milling machine: A general-purpose milling machine is a milling machine that is manually operated by the operator. When moving the relative position of the tool and the workpiece, the operator needs to judge and set the machining conditions such as the position, feed, speed, and cutting amount of the tool. Fine and high-quality finished products can be completed manually.
  • CNC milling: CNC milling is a machining process that uses a computer to control the processing conditions. The machine's built-in computer performs CNC controlled operations automatically using 3D CAD/CAM software. They save labor and can be used in the machining of complex shapes.
  • Machining center:  A machining center refers to a machine tool with CNC control. It is a multi-axis, compound machine that can be installed with different tools on multiple spindles. A machining center makes it is possible to simultaneously perform different types of cutting, drilling, or surface machining. By combining linear motion with rotary motion, the machining center can complete machining of more complex shapes.
  • CNC gear processing machine: Using the CNC gear processing machine with a built-in computer, it is possible to process and manufacture gears of various shapes and sizes, such as those used in clocks and automobiles.

Lathe Processing:

Lathe processing is a procedure performed on the outer periphery of a workpiece as it turns. The workpiece can be machined into round or tapered shapes, and threads and grooves can also be cut into the workpiece.

  • General lathe:  This is a lathe in which the operator manually feeds and replaces tools. The  lathe uses a fixture called a collet to hold the workpiece as it is spun it at high speed for machining. Very compact desktop lathes can be used on a workbench to machine very small parts.
  • CNC lathe: Lathe machining using computer-control, allows even beginners to perform machining with high quality. Since it automatically replaces multiple tools, it also increases work efficiency. CNC automatic lathes can be programed to process irregular shapes such as cams.

The Basic Process of Cutting:

  • Cutting action: Cutting refers to the action of using a tool to cut off a part of the target workpiece.  The cutting action involves the action of successively shaving off strips of material from the workpiece. The tool, such as a turning tool, moves in a straight line across the surface of the workpiece. The workpiece is then fed into the machine in a direction perpendicular to the cutting direction, and the cutting action is repeated. Successive repetitions of this action create a plane surface on the workpiece.
  •   Processing and resistance: Since the tool and the target are in contact with each other during processing, and the forces interfere with each other, resistance occurs. When working, resistance produced must be considered. When cutting with a turning tool, the resistance will vary depending on factors such as the material of the workpiece, the cutting area, or the type of cutting tool. The cutting area will affect the resistance, and special attention must be paid to the size and shape of the area being processed. When drilling, the type of drill (tip shape), torque resistance, drill rotation speed, feed rate, and material of the target, must all be considered.
  • Processing and speed: Work efficiency as well as quality control are important issues. Machining increases efficiency by increasing the processing speed. But increasing the speed may have negative effects such as increased drag, and thermal deformation, etc. Increasing the machining speed may also shorten the life of the turning tool, increasing the frequency of tool changing required, making the cost per machining unit higher. Therefore, it is very important to consider how speed will affect the tools performance and lifespan.
  • Processing and temperature: As we mentioned earlier in resistance and speed, when performing machining such as cutting, the contact between the target and the tool generates heat. This may increase the temperature inside the target, affecting machining accuracy or tool durability. The faster the processing speed, the more heat is generated. The larger the processing area, the higher the friction, which will increase the temperature. Therefore, when performing machining, it is important to keep an eye on temperature changes. Cutting fluids play an important role in the temperature management of machining. They can reduce the wear between the target and the tool, therefore reducing the heat generated. In the past, most the cutting fluids were oil-based, but now, due to the rising awareness of environmental protection, water-soluble cutting oils have become the mainstream. In addition, because machining requires a large amount of cutting fluid, most of them will use a circulating type device to filter the used cutting fluid and reuse it.

Matters Needing Attention in Cutting Processing:

As the resistance generated by different tools is varies from tool to tool, the influence of resistance must be considered during processing. Different processing methods can be considered to choose the process best suited to give the best efficiency, improve tool durability, and product the best quality.

Improper rotational speed will lead to problems such as increased resistance, thermal deformation, and shortened tool life. Before processing, adjust the speed according to the job situation, pay attention to temperature changes, and make good use of cutting fluid.

The key to striking a balance between speed and quality machining is not based on just a single factor. Correct selection of cutting tools, arranging reasonable procedures, improving environmental conditions, and selecting high-performance cutting fluids can ensure efficient and high-quality machining. Smart tool handling and proper monitoring of the cutting process will optimize the process, improve the quality of the finished product, reduce costs, and even help to avoid accidents.


Published by Apr 13, 2022 Source :machsync, Source :keyence

Further reading

You might also be interested in ...

Headline
Knowledge
Motion Control Systems in Factory
Motion control encompasses every technology related to the movement of objects. Motion control is also referred to as Servo Control or Robotics and is implemented in industrial processes to move specific loads in a controlled way. It is the core technology of factory automation and is the real-time management of the position and speed of mechanical moving parts according to the expected motion trajectory and specified motion parameters.
Headline
Knowledge
What is Rapid Tooling Molding Technology?
Rapid molding technology is a fast, convenient, and practical mold manufacturing technology. It is especially suitable for the development and trial production of new products, process verification, and functional verification, as well as multi-variety and small batch production.
Headline
Knowledge
Anode Material Technology and Application in Lithium Batteries
The negative electrode material refers to the raw material that constitutes the negative electrode in the battery. The negative electrode of lithium-ion battery is made of negative electrode active material carbon material or non-carbon material, binder and additive to make paste glue, which is evenly spread on both sides of copper foil, dried and rolled. The key to the successful fabrication of lithium-ion batteries lies in the preparation of negative electrode materials that can reversibly de/intercalate lithium ions.
Headline
Knowledge
Do You Know About Drilling Machine?
Drilling machine is a general-purpose machine tool with a wide range of uses, which can process parts such as drilling, reaming, flat plane and tapping. When the drilling machine is equipped with process equipment, it can also carry out boring, and when the drilling machine is equipped with a universal worktable, it can also carry out drilling, and reaming.
Headline
Knowledge
Introduction of the Broach
The so-called broach refers to the order of size, the rough cutter and the fine cutter. Most of the cutters are mainly installed on the broaching machine, which is called the broach. Broach is a forming tool used for broaching. There are multiple rows of cutter teeth on the surface of the cutter, and the size and shape of each row of cutter teeth increase and change sequentially from the cutting end to the cutting end. When the broach makes a broaching motion, each tooth cuts a certain thickness of metal from the workpiece, and finally obtains the required size and shape.
Headline
Knowledge
The Three Key Enterprise Applications of Edge Computing Are Closely Related to Cloud, Industrial Internet of Things, and 5G
Edge Computing is a distributed network architecture that allows data to be processed and analyzed closer to its source, moving resources such as computing, storage, and network bandwidth as close to users (or endpoints) as possible. Industrial Internet of Things (IIoT), artificial intelligence, big data analysis to 5G networks, edge computing can be said to be the expansion and extension of IT environments and computing technologies that seek common ground in differences.
Headline
Knowledge
What are the Male Mold and Female Mold?
A pair of molds is composed of an upper mold and a lower mold. The male die is a concave die, also known as the upper die. The design of the male mold is very important, and the structural characteristics of the female mold itself change with the structure of the product and the processing method of the mold, which is flexible.
Headline
Knowledge
What is Laser Cutting and Uses?
There is more than one type of laser cutting. It can use different medias to generate lasers of different wavelengths, so the scope, characteristics and functions of the applications are different. In the following, the article will take you to understand the uses of laser cutting in different fields, so that you can better understand the laser cutting technology.
Headline
Knowledge
What is A Punch? Introduction of Punching Principles, Types and Materials
A punch, also known as a punch press, is a forming process technology. There are many kinds of it. Due to different structural principles, the price and processing effect will change in response, but they all have the same structure. With the rapid development of the stamping industry, competition in all walks of life has increased. "Punches are also used in various industries, such as aerospace, education, auto parts, diving equipment and so on.
Headline
Knowledge
What is an Injection Mold?
An injection mold is a tool for producing plastic products; it is also a tool for imparting complete structure and precise dimensions to plastic products. Because the production method is to inject the plastic melted at high temperature into the mold through high pressure and mechanical drive.
Headline
Knowledge
What is a Belt Drive?
A method of transmitting rotational force between two separated shafts using pulleys and belts. The rotation speed ratio is inversely proportional to the diameter of the two pulleys, and it can slide when the load is excessive to prevent mechanical damage.
Headline
Knowledge
What Do You Know About Planetary Reducer?
Planetary reducer has been in existence for more than 30 years. During this long period of time, planetary reducer has gradually entered the field of automation from only appearing in high-end equipment in Europe and America, and has been widely used in machine tools, semiconductors, and packaging industries in recent years. The equipment in the medical food industry, aerospace and other fields will be used with planetary reducers. High, medium and low power servo motors with planetary reducers have become standard. What are the applications and advantages of planetary reducers? This article will let you know more about planetary reducers.
Agree