We often hear that there are hard rails and linear rails in CNC machining centers. Is the hard rail better or the linear rail better? What is the difference between the two?
CNC Machining Center: What is a hard track? What is a linear track?
Hard rail refers to the rail and bed is one casting, and then machined on the basis of the casting rail. That is, the shape of the guide rail is cast on the bed, and then machined into the guide rail after quenching and grinding, there is also the bed and guide rail is not necessarily one piece, such as inlaid steel guide rail, which is machined and nailed to the bed.
Line rail usually refers to rolling guide, is now often used in the machine tool industry, the kind of linear module used, we usually call such components for “linear guide”.
Is hard rail better? Is it better to have a linear track?
In fact, there is nothing good or bad about hard rails and linear rails, they can only be said to be suitable or not because their focus is different. Let’s take a look at their respective advantages and disadvantages.
1. Advantages, disadvantages and applications of hard rail
The hard rail has a large sliding contact surface, good rigidity, strong shock resistance, strong load-bearing capacity, and is suitable for heavy-duty cutting.
The hard rail is dry friction. Due to the large contact surface, the friction resistance is also large, and the moving speed cannot be too fast. At the same time, crawling is easy to occur, and the gap on the moving surface will cause machining errors. The maintenance of the machine tool track is the top priority. Once the track is not sufficiently lubricated, it will cause the track to burn or wear out, which is fatal to the accuracy of the machine tool.
The application of hard rails is suitable for heavy cutting, large molds, high hardness workpieces, and workpieces with general accuracy requirements.
2. Advantages, disadvantages and applications of linear rails
Nowadays, the running speed of many machine tools is extremely fast, especially the idle speed. This is largely due to the credit of the linear rail; the linear rail can be pre-tensioned to achieve zero gap between the rails with high accuracy; in terms of service life, the linear rail is much higher than the hard rail.
The cutting force of the linear rail is smaller than that of the hard rail. It is only for the hard rail. In fact, the linear rails of many machine tools have greatly improved their carrying capacity.
The application of linear rail is suitable for high-speed machines, high-speed cutting, suitable for processing products and small precision molds. Nowadays, more precision machining centers use linear rails.
