1. Firstly, in the different concepts of machining centers, engraving and milling machines, and engraving machines
At the beginning of our country, there were only CNC engraving machines, and the biggest advantage of engraving machines was carving. Its disadvantage was that it was unable to process materials and workpieces with higher hardness. Subsequently, engraving and milling machines emerged in the later stage, filling the gap of engraving machines. They can both carve and mill, making them a high-precision CNC machine tool.
Engraving and milling machines are suitable for milling small workpieces, precision machining of small molds, and processing materials such as copper and graphite; While low-end engraving machines prefer to process non-metallic plates with low hardness such as wood, bicolor plates, and acrylic plates, high-end engraving and milling machines are more suitable for polishing and polishing wafers, metal shells, etc., while the machining center is large in size and heavy in weight, which is mainly used for processing workpieces with large milling quantities. Large molds are suitable for materials with high hardness, and are also suitable for roughening common molds.
2. The rotational speed of the machining center is different from that of the engraving and milling machine
CNC machining center machines are usually equipped with 8000rpm/min as standard; The most common engraving and milling machine is 240000 rpm/min. Engraving machines are generally the same as engraving and milling machines, with very high rotational speeds. If used for high gloss processing, engraving machines can even reach 80000 rpm/min. Generally, engraving and milling machines use electric spindles, and if the rotational speed can reach 80000 rpm/min, they use air floating spindles.
3. The spindle power of the machining center engraving and milling machine is different
CNC machining centers use the BT-40 spindle, while engraving and milling machines use the BT-30 spindle. CNC machining centers typically range from several thousand watts to tens of kilowatts, while engraving and milling machines typically only range within ten kilowatts
The cutting tools can be divided into five categories according to the form of the surface processed by the workpiece:
Tools for processing various external surfaces, including turning tools, planers, milling cutters, external surface broaches, files, etc;
Hole processing tools, including drills, reamers, boring cutters, reamers, internal surface broaches, etc;
Thread processing tools, including taps, dies, automatic thread cutting heads, thread turning tools, thread milling cutters, etc;
Gear processing tools, including hobs, gear shapers, shaving cutters, bevel gears, cutting tools, etc;
Cutting tools, including serrated circular saw blades, band saws, hacksaws, cutting turning tools, TPSG extrusion tap TINs, etc.
In addition, there are also combination tools.
According to the cutting motion mode and corresponding blade shape, cutting tools can be divided into three categories:
Universal tools, such as turning tools, planers, milling cutters (excluding formed turning tools, forming planers, and forming milling cutters), boring cutters, drill bits, reamers, cutting tools, and saws;
Forming tools, whose blades have the same or nearly the same shape as the cross-section of the workpiece being processed, such as forming turning tools, forming planers, forming milling cutters, broaches, conical reamers, and various thread processing tools;
Generative cutting tools are used to process the tooth surface of gears or similar workpieces, such as hobs, gear shapers, shaving cutters, bevel gear planers, and rolling knurling cutters, using the generative method
CNC machining centers are divided into wire rail type machining centers and hard rail type machining centers. So what are the differences between them before? What machining centers were used for machining parts and what machining centers were used for machining molds? Today we will discuss this issue in detail, so that when choosing a machining center in the future, everyone can know whether to use wire rails or hard rails
What is the difference between CNC line rail machining centers and CNC hard rail machining centers?
Line Rail Processing Center: What is a line rail? In fact, its full name is linear guide rail, which generally refers to rolling guide rail. At present, we often see two types of structures: one is a ball guide, and the other is a roller guide. The difference between these two types is that the ball guide is a point contact type, and the roller guide is a line contact type. In fact, their principles are the same, mainly rolling on the guide to drive sliding.
What are the advantages of CNC rail machining centers
1. The linear guide rail is supported by rolling parts, and its rolling and sliding performance is stronger than that of the hard rail friction and sliding performance, without climbing
Appearance.
2. Due to its small coefficient of friction, it moves faster.
3. Also, due to the small coefficient of friction, the wear is relatively small.
4. Generally, linear guides are made of better materials and more precise equipment, so their accuracy is also high.
5. The later maintenance is convenient, and after the guide rail is worn, the replacement of the line rail is convenient, while the hard rail is more troublesome due to the need to adjust the clearance.
Disadvantage of CNC rail machining center: Due to its small contact surface, its rigidity is lower than that of hard rails.
What is a CNC hard rail machining center?
The hard rail, as we often refer to it, refers to the integrated casting of the guide rail and the bed. Its material grade is generally not lower than HT250, and the Brinell hardness of the body is between HB180-HB240. After high-frequency or ultra audio quenching treatment, the hardness of the guide rail is generally above HRC50 °, making it have excellent wear resistance (steel embedded guide rails are also a type of hard rail). The hard rails used in CNC machining centers are generally rectangular structures, commonly known as rectangular guides.
What are the advantages of a hard rail machining center?
Advantages: The sliding contact surface of the hard rail is large, making the machine tool rigid and stable.
What are the drawbacks of hard rail machining centers?
Disadvantages: Due to the large contact surface, the friction resistance is also high, the wear is fast, the movement speed is limited, and defects such as crawling are prone to occur. Therefore, most machining center machine manufacturers use the rail pasting process to reduce the wear and creep defects of hard rails.
How to choose CNC line rail machining center and CNC hard rail machining center
Due to its faster speed and higher accuracy, the wire rail machining center is suitable for high-speed cutting, making it more suitable for processing small precision molds or workpieces with low hardness and high accuracy. However, there are gaps on the moving surface of the hard rail machining center for movement, and the friction coefficient is high, which can easily cause adhesion and lead to machining errors. Therefore, the hard rail machining center is more suitable for processing workpieces with high hardness, However, workpieces with low precision requirements are processed.
After understanding the above knowledge, you must know how to choose between a wire rail machining center and a hard rail machining center.
