## Constant linear speed turning

[Constant Linear Speed ​​Cutting] is also called fixed linear speed laser cutting, which means that when turning non-cylindrical inner and outer diameters, the turning speed of the lathe spindle can be continuously changed to keep the cutting linear speed at the real-time cutting position constant (constant). CNC lathes above mid-range generally have this function. Using this function can not only improve the work efficiency, but also improve the quality of the cnc machining surface, that is, the consistency of the surface roughness of the cut end surface or conical surface.

Take the two steps above as an example.

The linear speed generally has a specific value. This value is given by the tool manufacturer. This value will be rigorously calculated after the blade is designed and produced. Then mark it behind the blade box. In fact, we will give a speed when turning an outer circle or an inner hole. This speed may be given according to experience, it may be told by your master, or written by a programmer. In fact, the most correct method is to use a formula to calculate Reasonable speed, what blade is turned at what speed, can not be damaged blade to turn high speed, high-end blade to turn low speed, to hold back him. How should this value be calculated?

V = ∏ * D * n / 1000

V: Linear speed Unit: m / min

∏: pi (3.14)

D: diameter of outer circle Unit: mm

n: speed unit: rpm

The specific value is calculated by the above formula. We must know the diameter of the workpiece in turning. It is the value of X when placed in the CNC machine. If there is this behind the Vc blade box, there is a constant. When the formula is transformed, it is easy to calculate.
Turn this step at a constant linear speed. If we use the above blade to turn, then we calculate the rotation speed of the tool under the outer circle of 40 and 80.

Looking at the above figure, we can see that the rotation speed is about 1300 when the diameter is 80 and 2700 when it is 40. In practice, there can be no such high, it is impossible to stand against the cutting parameters. To reduce a grade, I said this, I want to tell you that the speed of the tool is different at different diameters. The diameter changes, the speed changes, and the cutting speed Vc does not. change. The biggest advantage of this is to ensure the stability of the cutting and benefit the life of the tool. Conducive to the roughness of the cnc machining parts surface.

How to show different outer circles in the program, the speed is different, and the Vc is the same. Is it to write an outer circle, you have to calculate a rotation speed yourself? It is not so complicated. In fact, it is very easy. In automatic programming, we only need to set a constant linear speed for turning, and specify a Vc to limit the maximum rotation speed. It’s the same, there is no difference, the program that comes out is that the program header is different, and the remaining node parameters are the same.