With the development of modern manufacturing technology, the selection of CNC equipment by enterprises has become an inevitable trend. Currently, the market offers a dazzling array of CNC equipment, and how to choose the right CNC equipment for one's enterprise in an economical and reasonable way has always been a topic of concern. This article provides a comprehensive discussion of the issues that should be considered during the selection process from a purely technical perspective.
For a manufacturing enterprise, improving production capacity often involves technological upgrades in areas such as production management, manufacturing processes, and production equipment. These aspects are interconnected and mutually restrictive. When selecting production equipment, CNC machine tools for upgrading, maintenance, and procurement during technological upgrades, it is essential to consider factors such as the intended operating environment, management methods, and optimal economic outcomes.
The selection of manufacturing equipment is for the purpose of manufacturing certain products. The chosen equipment may be used for processing some parts of a product, or it may be used for all parts. The level of manufacturing depends first and foremost on the design of the technological process, which determines the methods and means of processing, and thus the basic requirements for the equipment used. This also forms the basis for the technical organization and management of production. After determining the basic requirements for equipment selection, the choice must be based on the available technological level of equipment on the market. For most small- to medium-batch manufacturing enterprises, choosing CNC machine tools to replace old machine tools or enhance production capacity is a growing trend.
Comparing the performance of conventional and CNC machine tools, CNC machine tools have the advantages of strong ability to process complex surface parts, adaptability to a variety of processing objects (high flexibility), high processing quality, precision and processing efficiency, adaptability to CAD/CAM networking, suitability for integrated management of manufacturing and processing information, high equipment utilization rate and low operating costs.
Choosing a CNC machine tool is a comprehensive technical issue. Currently, both domestic and international manufacturers offer a wide variety of equipment. Over the decades, CNC machine tools have evolved into a vast family, capable of fulfilling diverse processing and manufacturing requirements. How to select suitable equipment from a large variety of expensive options, how to ensure these machines function effectively in manufacturing while also meeting the company's future development needs, and how to correctly and rationally select accessories, tools, software, and after-sales technical services to achieve a good return on investment… these are all issues that purchasers must consider and address one by one.
I. Determine the typical workpiece "family"
Determining what types of parts to process is the first step in equipment selection. Based on technological upgrades and production development needs, enterprises determine which parts and processes will be handled by new processing equipment, taking into account long-term product development plans. These parts are then grouped and categorized using group technology to identify typical part families that will be the primary processing targets. During categorization, problems often arise such as significant differences in part size and shape, and processing times for various parts far exceeding the equipment's full-capacity operating time. Therefore, it is necessary to further select typical workpiece families that closely match the production requirements. Typical workpiece families can be categorized by shape into rhomboid (box-type), plate-type, rotating body-type (disc, sleeve, shaft, flange), and irregular-shaped types; and by processing accuracy requirements into standard and precision grades. Once the typical parts are clearly categorized, the basic processing equipment becomes clearer.
II. Process Design of Typical Part Families
After determining the parts to be machined, the process flow must be redesigned from the perspective of CNC machining technology. This includes transforming the original production process, exploring the feasibility of implementing new process methods, exploring the feasibility of implementing modern production and logistics management, exploring the feasibility of using advanced tools and fixtures to significantly improve production efficiency, and exploring the rational configuration of CNC equipment and other equipment (ordinary and special-purpose machines) on the production line. The goal is to obtain the optimal manufacturing process after using CNC machine tools. Below are the rational machining processes for several typical types of parts.
☆Shaft parts: Milling end face and drilling center hole → CNC lathe (rough machining) → CNC grinding machine (finish machining);
☆Flanges and discs: CNC lathe (rough machining) → Turning center (finish machining);
☆ Cavity mold parts: Machining the outer shape and base surface on a conventional machine tool → Machining the profile on a CNC milling machine → High-speed CNC milling for finishing → Polishing or electro-etching the profile;
☆Plate-plate parts: Machining large flat surfaces on a dual-axis milling machine or gantry milling machine → Machining various holes on a vertical machining center;
☆Box-shaped parts: Machining the bottom surface on a vertical machining center → Machining the four sides and all process surfaces on a horizontal machining center.
The following factors should be considered when arranging the process flow:
(1) Select the shortest processing flow.
(2) CNC machine tools have considerable adaptability, but they are not omnipotent. From an economic point of view, each part in a typical workpiece family has an economic batch size, and more advanced process methods should be used based on the economic batch size.
(3) Make the most of the various process features of the machine tool and strive to maximize the comprehensive processing capabilities of the CNC machine tool (the process features of multi-process concentration). The minimum number of machine tools, process equipment and fixtures should be configured in the production process.
(4) The balance of the capabilities of various equipment in the production line or workshop should be considered. As a selection of a single CNC machine tool or the configuration of a production line, a single piece of equipment cannot completely cover all the processing steps of a workpiece. There will inevitably be process transfers with other equipment. The production capacity of each piece of equipment should be balanced to meet the comprehensive requirements of the production cycle. Therefore, the arrangement of the number of processes and the sequence of processing steps on each piece of equipment should not only give full play to the strengths of each CNC machine tool and meet the accuracy requirements, but also further consider the reasonable use of the process reference when the workpiece is transferred between each machine tool.
(5) A common problem encountered in arranging CNC machining processes is the contradiction between process concentration and the principle of progressive refinement. In the use of CNC machine tools, the principle of process concentration is generally adopted, aiming to complete multiple processes on a single machine tool to improve productivity, shorten the part processing cycle, and even complete the machining of the entire workpiece in a single setup. However, in reality, for some complex workpieces with high precision requirements, it is difficult to complete all machining in a single setup due to process factors such as thermal deformation, workpiece deformation caused by internal stress, fixture clamping deformation, and the aging requirements of heat treatment, as well as programmer operational factors. The requirement for progressive refinement of machined parts in the basic process guidelines restricts the number of process concentrations. Properly handling this contradiction is an important aspect of CNC machining processes.
(6) In arranging the process flow for typical workpiece families, the manual adjustment and testing of each machine tool and production line should be properly arranged, i.e., the impact of manual intervention. Enterprises should determine the degree of manual intervention in the process flow based on their own technical equipment capabilities, technical level, and investment in technological transformation. This determines the automation level and functional requirements of the selected CNC machine tools. Appropriate use of manual adjustment should be objectively considered to supplement the enterprise's ability to achieve full automation, and the enterprise's process capabilities and equipment level should be accurately positioned.
III. Selection of Main Feature Specifications of CNC Machine Tools
Machine tool specifications should include the machine type, machine tool parameters, and main motor power. Once the process is determined, the machine type selection becomes clearer. For example, for machining rotary parts, the main available equipment includes lathes, turning centers, and CNC grinding machines; for machining box-shaped parts, vertical or horizontal machining centers are preferred.
CNC machine tools have developed into a wide variety of products with numerous options available. When choosing a machine, simplicity is key, provided it meets the machining process requirements. For example, both turning centers and CNC lathes can machine shaft-type parts, but a turning center meeting the same machining specifications will cost several times more than a CNC lathe. If there are no further process requirements, choosing a CNC lathe is reasonable. In machining cavity mold parts, both CNC milling machines and machining centers of the same specifications can meet basic machining requirements, but the price difference between the two types of machines is 20%–50%. Therefore, for mold machining processes requiring frequent tool changes, a machining center is preferable, while for milling with a fixed tool for extended periods, a CNC milling machine is more suitable.
The most important specifications of a CNC machine tool are the travel range of its CNC axes and the power of its spindle motor. The travel of the three basic linear coordinates (X, Y, Z) of the machine tool reflects its allowable machining space. In a lathe, the two coordinates (X, Z) reflect the allowable size of the rotating body. Generally, the outline dimensions of the workpiece should be within the machining space of the machine tool. For example, if a typical workpiece is a 450mm × 450mm × 450mm box, then a machining center with a worktable size of 500mm × 500mm should be selected. Choosing a worktable slightly larger than the typical workpiece is for fixture installation considerations. There is a certain proportional relationship between the machine tool's worktable size and the travel of the three linear coordinates. For example, in the above-mentioned machine tool with a worktable of 500mm × 500mm, the x-axis travel is generally (700-800)mm, the y-axis is (500-700)mm, and the z-axis is approximately (500-600)mm. Therefore, the size of the worktable essentially determines the size of the machining space. In some cases, the workpiece size may be larger than the coordinate travel. In this case, the machining area on the part must be within the travel range, and the allowable load-bearing capacity of the machine tool table must be considered, as well as a series of issues such as whether the workpiece will interfere with the space of the tool exchange with the machine tool, and whether it will interfere with accessories such as the machine tool guard.
The power of the main motor in a CNC machine tool can vary across different machine tools of the same specifications, generally reflecting the machine tool's cutting rigidity and high-speed spindle performance. For example, the spindle motor power of a light-duty machine tool may be 1-2 levels lower than that of a standard machine tool. Currently, the spindle speed of a typical machining center is (4000-8000) r/min, while high-speed vertical machine tools can reach (20000-70000) r/min, and horizontal machine tools (10000-20000) r/min, with their spindle motor power increasing significantly. The spindle motor power reflects the machine tool's cutting efficiency and, from another perspective, its cutting rigidity and overall machine tool rigidity. In modern small and medium-sized CNC machine tools, mechanical speed changers in the spindle box are rarely used; instead, high-power AC adjustable speed motors are often used to directly drive the spindle, or even electric spindle structures are employed. This structure limits torque at low speeds, meaning the output power of the speed-regulating motor decreases at low speeds. To ensure sufficient low-speed output torque, a high-power motor must be used. Therefore, the spindle motor of a CNC machine tool of the same specifications is several times larger than that of a conventional machine tool. When a user has a large number of low-speed machining operations on typical workpieces, the low-speed output torque of the selected machine tool must also be checked. Light-duty machine tools are certainly cheaper, and users should comprehensively select the machine tool based on factors such as the blank allowance of their typical workpieces, cutting capacity (metal removal per unit time), required machining accuracy, and the types of cutting tools that can be configured.
In recent years, the trend towards higher speeds in CNC machine tools has been rapid. Spindle speeds have increased from several thousand to tens of thousands of revolutions per minute, and rapid traverse speeds for linear coordinates have risen from 10-20 m/min to over 80 m/min. Naturally, machine tool prices have also increased accordingly, requiring users to make informed choices based on their technical capabilities and equipment availability. For example, the maximum spindle speed on a vertical machining center can reach 50,000-80,000 r/min, and except for some special machining cases, the corresponding cutting tools are generally very expensive. Some high-speed lathes can reach speeds of 6,000-8,000 r/min or higher, requiring high-performance cutting tools.
For a small number of special workpieces, machining with only three linear coordinates is insufficient. It is necessary to add rotary coordinates (A, B, C) or additional tool coordinates (U, V, W). Currently, these requirements can be met by machine tools on the market, but the price of machine tools will increase significantly. In particular, for some requirements such as four-axis or five-axis linkage machining, a comprehensive consideration and arrangement of the corresponding programming software and measurement methods is necessary.
IV. Selection of Machine Tool Precision
The precision requirements for machining key parts of typical components determine the precision level of the CNC machine tool selected. CNC machine tools are further categorized according to their application, including basic, full-function, and ultra-precision types, each with varying achievable precision. Basic CNC machine tools are currently used in some lathes and milling machines, with a minimum motion resolution of 0.01 mm and motion and machining accuracy both above (0.03-0.05) mm. Ultra-precision CNC machine tools are used for special machining operations, achieving precision below 0.001 mm. This discussion primarily focuses on the most widely used full-function CNC machine tools (mainly machining centers).
According to accuracy, CNC machine tools can be divided into ordinary type and precision type. Generally, there are 20 to 30 accuracy inspection items, but the most characteristic items are: single-axis positioning accuracy, single-axis repeatability positioning accuracy, and roundness of test pieces processed by two or more axes.
Positioning accuracy and repeatability comprehensively reflect the overall accuracy of all moving parts of the axis. Repeatability, in particular, reflects the positioning stability of the axis at any point within its stroke, a fundamental indicator of its stable and reliable operation. Modern CNC systems have rich error compensation functions, capable of stably compensating for system errors in each link of the feed transmission chain. For example, variations in the clearance, elastic deformation, and contact stiffness of each link in the transmission chain often reflect different instantaneous motion quantities depending on the load on the worktable, the length of the travel distance, and the speed of the positioning movement. In some open-loop and semi-closed-loop feed servo systems, the mechanical drive components downstream of the measuring element are also significantly affected by random errors due to various accidental factors, such as the drift in the actual positioning position of the worktable caused by the thermal expansion of the ball screw. In short, if given the choice, choose the equipment with the best repeatability!
Milling accuracy of cylindrical surfaces or milling spatial helical grooves (threads) is an indicator for comprehensively evaluating the servo following motion characteristics of the CNC axes (two-axis or three-axis) and the interpolation function of the CNC system of a machine tool. The evaluation method is to measure the roundness of the machined cylindrical surface. In CNC machine tool test cuts, there is also the method of milling oblique square quadrilaterals, which can also determine the accuracy of two controllable axes during linear interpolation motion. When performing this test cut, a milling end mill for finishing is mounted on the machine tool spindle, and a circular test piece placed on the worktable is milled. For small and medium-sized machine tools, the circular test piece is generally taken to be between Ф200 and Ф300. Then, the cut test piece is placed on a roundness meter to measure the roundness of its machined surface. Obvious milling cutter vibration marks on the milled cylindrical surface indicate that the interpolation speed of the machine tool is unstable; obvious elliptic error in the milled roundness indicates that the gain of the two controllable axis systems of the interpolation motion is mismatched; when there are tool stop marks at the points where the controllable axis moves in different directions on the circular surface (in continuous cutting motion, when the feed motion stops at a certain position, the tool will form a small section of extra metal cut off on the machined surface), it indicates that the forward and reverse clearance of the axis is not properly adjusted.
Single-axis positioning accuracy refers to the error range when positioning at any point within the axis's travel. It directly reflects the machining accuracy capability of a machine tool, making it the most critical technical indicator for CNC machine tools. Currently, the regulations, definitions, measurement methods, and data processing for this indicator vary among countries worldwide. Commonly used standards in various CNC machine tool catalogs include the American National Standard (NAS) and the recommended standards of the American Machine Tool Builders' Association (ANP), German Standard (VDI), Japanese Standard (JIS), International Organization for Standardization (ISO), and Chinese National Standard (GB). Among these standards, the Japanese standard has the lowest requirements because its measurement method uses a single set of stable data as a basis, then uses ± values to halve the error value. Therefore, the positioning accuracy measured using its method is often more than twice as high as that measured using other standards.
Although the other standards differ in how they process data, they all reflect the need to analyze and measure positioning accuracy according to error statistics. That is, the error of a positioning point in the travel of a certain controllable axis of a CNC machine tool should reflect the error of that point being positioned thousands of times during the long-term use of the machine tool. However, we can only measure a limited number of times (usually 5-7 times) during the measurement.
V. Selection of CNC System
As market demands diversify, machine tool manufacturers often offer the same machine tool with multiple CNC options or multiple CNC system functions.
The CNC systems provided by machine tool manufacturers are divided into mainstream systems and adaptable systems. Mainstream systems are generally more technologically mature, but they have different requirements for users. For example, users may have requirements such as a pursuit of quality from well-known brands, a desire for better after-sales technical support in China, or that the CNC systems used by the user unit are concentrated in a few companies, so as to facilitate user mastery and spare parts availability. Therefore, users prefer to configure CNC systems that they trust or are familiar with.
The performance of available CNC systems varies greatly, directly impacting equipment price. Therefore, one should not unilaterally pursue high-level or new systems, but rather prioritize the performance of the main machine tool, conducting a comprehensive analysis of system performance and price to select a suitable system. Currently, some of the world's more renowned CNC systems include FANUC (Japan), SINUMERIK (Germany), NUM (France), FIDIA (Italy), FAGO (Spain), and AB (USA). Major machine tool manufacturers also have their own systems, such as MAZAK and OKUMA. Domestically, there are also CNC system suppliers from companies like Aerospace Group, Electromechanical Group, Huazhong University of Science and Technology, Liaoning Lantian, Nanjing Dafang Group, and Northern Kaiqi, each offering a range of products in various specifications.
The basic principles for users to choose a system are: high performance-price ratio, convenient use and maintenance after purchase, and long market life (do not choose obsolete systems, otherwise spare parts will not be available after a few years of use).
In addition to the basic functions, CNC systems offer many optional features. For systems integrated into machine tools, since the basic CNC system functions required for machine tool use are already selected by the manufacturer, users can add additional functions to their order list based on their production management, measurement requirements, tool management, programming requirements, etc., such as DNC interface networking requirements.
VI. Selection and Configuration of Automatic Tool Changer (ATC), Automatic Tool Changer (APC), and Tool Holder
1. Choosing an ATC
On CNC machine tools with comprehensive machining capabilities, such as machining centers, turning centers, and CNC punch presses with interchangeable punches, automatic tool changers (ATCs) are a fundamental feature. Their performance directly affects the overall quality of the machine and constitutes a significant portion of the equipment investment (accounting for 10%–30% of the total cost). Therefore, when selecting the main machine tool, the performance and tool storage capacity of the ATC must be carefully considered. Currently, the selection of ATCs for machining centers is relatively standardized. The following section uses the ATC device in a machining center as an example to illustrate the selection principles.
Field experience shows that about 50% of the failures in machining centers are related to the ATC device. However, the ATC is a basic component for improving the processing efficiency of the equipment. Therefore, it is recommended that users choose ATC with simple structure and high reliability as much as possible, while meeting the usage requirements. This can also reduce the price of the whole machine accordingly.
The following describes the main technical parameters related to the ATC device.
(1) Tool holder model
The tool holder type depends on the specifications of the tool holder mounting hole on the machine tool spindle. Currently, most machining center spindles use the ISO-specified 7:24 taper bore, commonly available in sizes 40, 45, and 50, with some also using sizes 30 and 35. Smaller machine tools generally require smaller tool holders, but smaller tool holders are disadvantageous for machining large and long holes. Therefore, if a larger tool holder is available for a given machine tool, it should be chosen, although this will affect the tool magazine capacity and tool change time. In recent years, machining centers and CNC milling machines have been developing towards higher speeds. Numerous experimental data show that when the spindle speed exceeds 10,000 r/min, the 7:24 taper bore will expand due to centrifugal force, affecting the tool holder's positioning accuracy. Therefore, one suggestion is to use the HSK series of short taper toolholders recommended by German VDI. In addition, there are some over-positioning taper toolholders in Japan that have simultaneous contact between the taper and the end face, but the HSK series is better in terms of centering accuracy and repeatability. Currently, there are very few manufacturers producing them in China.
For tool holders with the same taper specification, there are Japanese BT standards, American CAT standards, German VDI standards, etc. They specify different sizes for the gripper of the robotic arm and different sizes for the tension pins of the tool holder. Therefore, all factors must be considered when making a selection. For users who already own a certain number of CNC machine tools or are about to purchase a batch of CNC machine tools, they should choose a single standard tool holder series that can be used interchangeably as much as possible.
(2) Tool change time
Tool change time refers to the time for exchanging tool holders, that is, the total time from removing the used tool from the spindle to installing a new tool. It can be further subdivided into two categories: tool-to-tool time and total tool change time (Chip-to-chip). Total tool change time includes the time from when the old tool finishes machining and leaves the machining area to when the new tool is installed on the spindle and ready for the next machining cycle. Currently, the fastest pure tool change time can reach approximately 0.7 seconds, while the total tool change time is between 3 and 12 seconds. Vertical machine tools generally have shorter tool change times than horizontal machine tools. Shorter tool change times mean higher machine tool productivity.
(3) Maximum tool weight
Maximum tool weight refers to the maximum allowable tool weight under automatic tool changing conditions. For a taper toolholder around 40, the maximum allowable weight is 7-8 kg; for a 50 taper toolholder, it's 15 kg; some heavy-duty tools can reach 25-30 kg, but the tool changing speed must be slowed down in these cases. The maximum tool diameter and length are mainly limited by the size and space of the tool magazine.
(4) Tool magazine capacity
Some machining centers offer several tool magazine capacities, ranging from a dozen to 40, 60, or 100 tools. Flexible machining units (FMCs) with central tool magazines can store nearly a thousand tools. The tool magazine capacity should generally be sufficient to meet basic needs and should not be too large, as larger capacities increase cost, complexity, and failure rate, and also complicate tool management. In single-machine operation, when changing to a new workpiece, the operator must clean the tool magazine according to the new process data. The more irrelevant tools in the magazine, the greater the cleaning workload and the more prone to human error. Therefore, users should generally calculate the required number of tools based on the process analysis of typical workpieces to determine the tool magazine capacity. If not considering a flexible machining unit or flexible manufacturing system, the tool magazine should generally be selected based on the number of tool holders required for a single workpiece clamping. According to foreign process analysis of typical workpieces processed by small and medium-sized machining centers, the tool storage capacity for small and medium-sized machine tools should be between 4 and 48 tools.
In machine tools incorporated into flexible manufacturing units, considering the requirement to process multiple workpieces and multiple processes simultaneously, a large-capacity tool magazine is required. In this case, corresponding tool management measures should be added.
2. Selection of knife handle and cutting tool
After determining the machine tool and automatic tool changer (ATC), the required tool holders and cutting tools (tools) must be selected. The tool holder series used in CNC machine tools are basically standardized, especially those used in machining centers, such as CAT from the US, BT from Japan, and JT from my country. CNC machine tools ultimately rely on cutting tools for machining workpieces, but the connection between the cutting tool and the machine tool, and the clamping position provided to the robot arm during automatic tool changing, all depend on the tool holder. Therefore, selecting tools essentially includes configuring both the cutting tool and the tool holder. The selection of the cutting tool depends on the machining process requirements. After the cutting tool is determined, a corresponding tool holder must be configured. For example, if the process requires drilling a small hole with a diameter of 6mm, then a 6mm diameter straight shank twist drill bit is selected, and a tool holder capable of holding the drill bit must also be chosen. Some tool holders now also come with dedicated cutting tools, such as precision boring tool holders. In short, most of these accessories are standardized and supplied by specialized manufacturers; machine tool users should select them appropriately based on the specific machining object. Since there is a wide range of tool holders to choose from, selecting too many will increase investment, while selecting too few will affect the machine tool's operating rate, so it should be treated with caution.
For machining workpieces with a total batch size exceeding several thousand pieces and repeated production runs, the use of composite tools can be considered in the process planning. This involves utilizing the advantages of CNC machine tools, such as high main cutting power and good machine tool rigidity, to perform powerful cutting with multiple blades and edges, thereby improving productivity and shortening the production cycle. However, a composite tool is much more expensive and becomes a specialized tool, so it is only economical when there is a sufficient quantity of workpieces.
In recent years, many new products have been developed for cutting tools used in CNC machine tools, greatly enriching the machining processes of CNC machine tools. Examples include universal vertical milling heads, back-scraping tools, deburring tools, speed-increasing heads, thread milling cutters, and internal cooling tools (see product catalogs for details).
3. Automatic worktable exchange
Automatic exchange tables are accessories configured on the main machine, and are available in quantities of 2, 4, 6, or 10. Except for dual exchange tables, they are primarily used in flexible manufacturing units. Dual exchange tables can significantly reduce auxiliary time for loading, unloading, positioning, and clamping complex parts, increasing machine tool uptime. However, adding this feature requires an additional investment of at least 100,000 yuan. Multiple exchange tables are used in flexible manufacturing units, suitable for 24-hour minimally staffed or unmanned management, and adaptable to the alternating production of multiple workpiece types. Here, it is crucial to implement enhanced quality inspection measures; otherwise, an investment increase of 20%–50% is uneconomical.
VII. Selection of Machine Tool Functions and Accessories
When selecting CNC machine tools, in addition to meeting the basic functional requirements and components, the optional functions and accessories should also be fully considered. The selection principle is: comprehensive configuration to fully utilize the maximum potential of the machine tool, taking into account both short-term and long-term benefits. For items that add only a small price increase but bring significant convenience to use, they should be configured as comprehensively as possible. Accessories should be provided to ensure the machine tool can be put into immediate use upon arrival at the site. It is crucial to avoid situations where a machine tool purchased for hundreds of thousands or even millions of yuan is rendered unusable for an extended period due to the lack of a single accessory costing tens or hundreds of yuan.
When selecting functions for a CNC system, practicality should be the primary consideration; too many functions are unnecessary, especially for equipment integrated into mass production lines. Simplicity is key. For machine tools with diverse product types and small batch production, enhanced programming functions are necessary, such as random program creation (background programming), motion graphics display, human-machine interface programming (GPS), and macro programming. While these can speed up programming, they also increase costs. Another option is to simplify the CNC system's programming functionality by configuring a separate automatic programming machine and its communication interface with the CNC system. Program processing is pre-processed on the programming machine, and then the data is sent to the CNC system after a few minutes. This approach further improves machine tool uptime.
Many accessories have been developed to improve machining quality and operational reliability, such as automatic measuring devices, contact probes and corresponding measuring software, tool length and wear detection, and machine tool thermal deformation compensation software. The selection principle for these accessories is to prioritize reliability over novelty. For auxiliary functional accessories, such as cooling, protection, and chip removal devices, the choice depends primarily on future on-site requirements and process specifications. For example, considering future requirements for machining large-mass cast iron parts, high-sealing protective covers, high-flow shower-type cooling systems, and paper coolant filters should be selected. In short, accessories should be selected to match production capacity.
VIII. Technical Services
As a high-tech product, CNC machine tools involve professional content from multiple disciplines. For such complex equipment, relying solely on the efforts of the user unit is far from sufficient, and indeed very difficult, to apply and maintain them effectively. It is essential to rely on and utilize professional teams in the industry. Therefore, when purchasing CNC machine tools, one should also comprehensively consider the pre-sales and after-sales technical services provided, with the aim of ensuring the equipment functions effectively as quickly and efficiently as possible.
For some new CNC machine tool users, the biggest challenge is not the lack of funds to purchase equipment, but the lack of a highly qualified technical team. Therefore, new users require personnel and technical support from the very beginning, including equipment selection, delivery, installation and acceptance, operation, programming, and mechanical and electrical maintenance. These conditions are difficult for users to resolve in a short time. Currently, machine tool manufacturers generally emphasize pre-sales and after-sales service, assisting users with process analysis of typical workpieces, conducting feasibility studies, and providing comprehensive technical services, including process equipment development, programming, installation and commissioning, trial cutting, and rapid warranty service after full production commencement. They also provide various technical personnel training programs for users.
In short, companies that prioritize building a strong technical workforce and improving employee skills will be able to make good use of CNC machine tools. Therefore, when selecting machine tools, it is recommended that users invest some funds in purchasing technical services tailored to their specific needs to ensure the equipment can be put to use as quickly as possible.
