How to Optimize CNC Machining Parameters for Efficiency?

CNC machines are machining metal workpieces with high precision and efficiency.

The manufacturing industry is developing continuously. The efficiency of CNC machining is becoming vital. It is crucial to shorten the production cycle and reduce the cost of parts. If a manufacturer only cares about how well the parts are made and how many are available. They do not consider how to improve production efficiency. So, their production costs are high. This will not help the business in the long run.

In this article, Yonglihao Machinery will discuss how to optimize CNC machining to increase efficiency. We will focus on parameter settings and advanced strategies. This will help you achieve high-quality production while improving efficiency.

Table of Contents

Understanding CNC Machining

CNC machining is a kind of automation technology. It uses a computer to control the tool on the machine. This tool does the work on the part. It involves controlling the machine tool to machine the workpiece according to specific paths and machining parameters by means of pre-programmed instructions from the CAM software. This can realize a high-precision and high-efficiency machining process. Therefore, CNC machining has become an indispensable and important machining technology in modern manufacturing.

CNC machine tools have these main parts. They are machine tools, CNC systems, power systems, tools, tool change systems, and other devices. A machine tool is also known as the host. It generally has four major parts: bed, spindle, table, and moving parts. The numerical control system includes a numerical control controller, computer, and programming equipment. The power system contains the drive system and spindle drive two parts. The tool and tool change system contains a tool and tool magazine for automatic tool change. The auxiliary device contains three parts: a cooling system, a lubrication system, and a fixture. The computer system controls the CNC machine tool. It allows for continuous automatic operation and maintains high accuracy.

CNC machining of metal parts, accuracy of machining parameters

The Importance of Optimizing CNC Machining Parameters

CNC machining is now widely used in fields like aerospace, car making, and electronics. Its importance in manufacturing is clear. Some products are more powerful now. This has raised the need for high precision in parts and surface quality. So, optimizing CNC parameters to boost this precision is critical.

Optimizing CNC machining parameters improves quality, speed, and delivery times. It extends tool life and cuts costs. In Addition, it creates precise, repeatable parts and boosts the whole enterprise’s capacity. It also enhances competitiveness and supports long-term growth.

Key Parameters to be Optimized in CNC Machining

In the process of CNC machining, the setting of cutting parameters may be different for each part of machining. To ensure that the machining of the finished parts achieves the best state, the cutting speed, feed speed, feed depth, tool radius compensation, and tool path need to be optimized and designed so that they can achieve the best results.

Cutting Speed

Cutting speed is the linear speed of the tool relative to the workpiece. Measure the distance the tool travels along the surface per unit of time when running at this speed. Cutting speed directly affects efficiency, quality, and tool life. Tool material, workpiece material, and processing type mainly affect speed. Other factors matter too. You need to choose the right speed for each material and tool.

The workpiece’s material affects cutting. Hard material needs a lower cutting speed. Soft material needs a higher cutting speed. Good tool materials resist wear and conduct heat. They can be used at higher cutting speeds. When roughing and finishing, the cutting speed for roughing is generally higher.

In general, you can choose the cutting speed by following the tool maker’s parameters. Then, use the workpiece to test cutting. Keep adjusting the parameters to get the best results.

Related Expansion: How To Select Cutting Tools For CNC Machining?

Feed Speed

Feed speed refers to the tool in the machining process along the surface of the workpiece moving speed, that is, the tool in the process of machining the distance moved per minute (usually in millimeters/minute or inches/minute). In addition, feed rate affects cutting force. It also affects chip formation, surface temperature, and machined surface quality.

A feed rate that is too high or too low can adversely affect the machining process. A high feed speed can lead to too much cutting force. This force deforms the workpiece and reduces the surface’s quality. A too-low feed rate reduces machining efficiency. It makes the production cycle longer. Therefore, the selection of feed rate needs to be integrated with cutting type, workpiece material characteristics and tooling, etc., generally in the pre-processing and also through the test cutting of the workpiece, based on experience and tool manufacturer manuals to determine the appropriate size of the feed rate.

Advanced CNC machining operations

Depth of Cut

The distance between the machined surface and the surface to be machined is the depth of cut when cutting the workpiece. It’s the depth of the tool each time it cuts into the workpiece. It mainly directly affects the cutting process of cutting force, temperature, surface quality, and tool life. In turn, it refers to the radial distance into the workpiece. Milling refers to the distance cut into the axial direction of the workpiece.

In general, the workpiece material, tool material, processing type, machine power, machine rigidity coolant, and other factors will affect the selection of the depth of cut, so the selection of the appropriate depth of cut, first of all, according to the factors affecting the first preliminary set a depth parameter, and then test cut the workpiece for fine-tuning the parameters, and finally record the results of multiple cuts and continue to optimize the depth of depth in order to achieve the optimal depth of cut so that you can Optimize machining efficiency, improve workpiece quality and extend tool life.

Tool Radius Compensation

Tool radius compensation corrects the error caused by the tool’s radius. It ensures the workpiece’s size and shape meet the design. There are two main modes of tool radius compensation: left compensation (G41) and right compensation (G42), which is used when the tool is located on the left side of the workpiece contour and vice versa. Tool radius compensation can be optimized by accurately measuring and entering the tool radius, dynamically adjusting the compensation value, and optimizing the program. By optimizing tool radius compensation, machining accuracy and efficiency can be improved and machining errors can be reduced.

Tool Path Optimization

Optimizing the tool path can significantly improve CNC machining efficiency and quality. Use CAM software to make the tool path from the workpiece’s shape. Then, simulate the tool path to find and fix problems and make it efficient. This will avoid empty strokes and broken tools.

First, use the CAM software to find the best tool path for the path simulation. This ensures that the path is free of collisions and interference. Then, use spiral feed and progressive withdrawal strategies to optimize the feed and withdrawal paths. Then, rationalize the machining process to reduce empty travel. Finally, the machining parameters are adjusted according to the actual situation to obtain the optimal path.

Tool Wear Patterns and Tool Life

In CNC machining, tool wear is a measure of machining effectiveness. It is an important method of calculating tool life. It can also change the quality of the part. For example, tool wear reduces the dimensional accuracy of the finished product and weakens the surface strength. This ultimately leads to increased vibration between the tool and the workpiece, damaging the workpiece. In most cases, these results impair efficiency.

Tool wear can be measured using both direct and indirect methods. When using the first method, indications from different signals must be guessed. Such as vibration, feed force, acoustics, and surface texture. The second method is to measure the tool wear area using a calibrated tool.

When the CNC machine control system notices that the tool life is getting shorter. The operator can then change settings to extend tool life. It can change cutting speeds, feeds, lubricant release, etc.

CNC machine with coolant spray optimizes the machining process and increases efficiency

Material Removal Rate (MRR)

Material removal rate (MRR) is a measure of CNC machining efficiency. It is the amount of material removed from the surface of the material in a given period of time (usually per minute.) A high MRR indicates high system efficiency, while a low MRR indicates low system efficiency.

The MRR is affected by a combination of feed rate, cutting speed, and depth of cut. For example, slow cutting speeds result in low MRR efficiency. This is because the tool will break, the finish will be poor, and production will be slow. On the other hand, an optimal cutting speed will result in an efficient MRR.

Revolutions Per Minute (RPM)

You can measure rotational speed in revolutions per minute or RPM. This number tells you how many revolutions per minute the spindle rotates around the longitudinal axis (spindle) RPM affects surface speed. A larger drill requires a slower RPM than a smaller drill for the same rim surface speed. For example, a drill-less than 3 millimeters (1/8 inch) in diameter requires 12,000 RPM or more to cut well without breaking. Larger drills require lower speeds.

RPM is not only affected by tool size. The type and hardness of the alloy being machined and the machining process are also important. This means that each object being drilled or cut has an optimum surface speed. There are five different ways to find the right drill RPM in a drill setup. Here are the five commonly used methods:

  • Built-in RPM calculations in CAM software
  • Dedicated calculator app
  • Operator experience
  • Standard formula (RPM equals four multiplied by the surface speed divided by the diameter of the drill)
  • RPM chart

Advanced Metrics for Deeper Insights

Scrap Rate and Part Conformity Rate

Scrap rate is the number of products made in a given period of time that do not meet the design requirements and have to be discarded. With that said, scrap just means time wasted making bad parts. A high scrap rate means that there are problems at different steps of the metal manufacturing or machining process. Simply put, it reduces the efficiency of CNC machining.

The opposite of this is the part pass rate. The part yield indicates how many qualified parts are produced in a given time. The higher part pass rate means that the efficiency of CNC machining is very good.

Overall Equipment Operation

Overall Equipment Efficiency (OEE) is a method of evaluating how well a machine is working. A problematic event (such as a broken machine part) can change it.OEE is expressed as a number. It is derived by combining a number of factors, such as machine availability, part quality rate, and performance efficiency. You need to look at setup time, tool change cycle time, downtime, maintenance downtime, and operating time to determine machine availability.

Variety of CNC Machining Tools and Drills to Increase Machining Efficiency

How Much Power or Energy is Used

One of the modern ways to measure the efficiency of CNC machining is to look at how much power or energy is being used. This is a good way to find out how often a CNC machine is running. The longer the machine runs, the more energy it uses. Likewise, the longer the machine runs, the more units are produced. This means the more efficient the machine is. If the energy consumption is low, it usually means that the machine only runs for a short time. Therefore fewer units are produced. Simply put, low energy consumption means low productivity.

Cost Per Part

To calculate the cost per part, divide the total cost of production by the number of parts. The lower the cost per part, the more parts are produced. This also means that the production process is more efficient. On the other hand, a higher cost per part means that fewer parts are being produced. This also means that the production process is less efficient.

Quality Control and Equipment Maintenance

In CNC machining, quality control, and equipment maintenance are key. They ensure machining accuracy and stability. These factors directly affect the final part’s quality.

Quality Control

Control of machining quality can be carried out in the following four aspects:

  • Process control: Process control monitors cutting force, vibration, and temperature in real-time. It does this with sensors and monitoring systems. They detect problems early so that measures can be taken to adjust.
  • Establishment of quality management system process: We will implement the ISO9001 quality management system. We will set up a perfect quality control process and record cards. These will ensure that every part is traceable and searchable.
  • Arranging professional inspectors for control: Arranging professional inspectors at the processing site is responsible for the first, middle, and last inspection of the parts at any time. They make inspection records and analyze processing problems. They also assist manufacturing engineers in adjusting and optimizing machining parameters.
  • Measurement using professional testing equipment: In order to ensure the reliability of the test data, the use of professional testing equipment (such as a coordinate measuring machine, universal tool microscope, imaging instrument, etc.) to measure the size of the workpiece, to ensure that the final processing dimensions of the workpiece in line with the design requirements.

Equipment Maintenance

Equipment maintenance can be carried out from the following three aspects:

  • Regular maintenance of machine tools: Regular lubrication, cleaning, and inspection of machine tools to ensure the normal operation of machine tool components to extend the service life of the equipment and machining accuracy.
  • Regular calibration of equipment: In order to ensure the accuracy and stability of processing, the processing equipment needs to be calibrated at regular intervals to ensure the quality of workpiece processing.
  • Maintenance of cooling system: Due to the long time processing production, the impurities in the equipment coolant will become more, which will block the pipeline and affect the cooling effect, so it is necessary to regularly clean the cooling system and replace the coolant to ensure the stability of the temperature during the machining process.

Strict quality control and good equipment maintenance can ensure that CNC machining makes quality parts. They also keep the equipment stable. They will improve part quality and production efficiency. At last, they will greatly raise the enterprise’s manufacturing level and capacity.

CNC milling cutters with multiple cutting edges for efficient metal machining

Summary

We need to optimize CNC machining parameters. This is key to improving efficiency, quality, and accuracy. We do this by setting the machining target. Then, we choose the right cutting speed, feed rate, and depth of cut. We also select the right tool radius compensation. We optimize tool paths and other key parameters. This improves efficiency and part quality. We also need to do good quality control and equipment maintenance. We must keep optimizing and improving. This helps enterprises to improve efficiency and competitiveness. It ensures their continuous development and innovation. This helps them to lead in the market.

Yonglihao Machinery specializes in machining mechanical parts. They have years of experience and expertise in CNC machining. If you need parts machining, please contact us. We will give you professional services and complete solutions.

FAQ

What are the most important parameters to optimize in CNC machining?

Choosing the right cutting speed, feed rate, and depth of cut is key. You also need to set the correct tool radius compensation and pick the best tool path. Doing this will optimize CNC machining.

How does intelligent machining technology improve efficiency?

Smart machining technology uses sensors and machine learning. They do real-time data analysis to adjust machining parameters. This improves tool life and part quality and boosts productivity.

Why is regular machine tool maintenance important?

Setting up a regular machine tool maintenance program has cleaning, lubrication, and calibration. It also includes inspections of critical components. It also stops surprise failures and ensures steady machine performance and efficiency.

How does toolpath optimization improve efficiency?

Efficient toolpaths minimize tool travel and shorten machining times. They also reduce tool wear and improve surface quality. This increases overall productivity.

What role does employee training play in optimizing CNC machining?

Proper training ensures that operators are skilled with the equipment. It helps them improve their skills, do routine maintenance, and cut scrap from human error. This improves efficiency and cuts costs.

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