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Chapter 4. How to Use a Milling Machine

Using an End Mill


What is the End Mill?

An end mill as shown in Figure 1 is one of the indispensable tools in the milling processing. The end mill has edges in the side surface and the bottom surface. The fundamental usage is that the end mill is rotated, and makes a plane of a material in the right-and-left direction or a plane of a bottom side of the end mill. We can make various shapes of mecahnical parts with the end mill.

The edge of the end mill is very weak. In case beginning o cuttings, we have to take care so that the end mill may touch to a material as slowly as possible.

Fig.1, End Mill

End Mill with Throw Away Tips

Figure 2 shows an end mill with throw away tips. When the tips have bad sharpness, they can be changed easily. Ant it gets good sharpness again.

Fig.2, End Mill with Throw Away Tips

Three Important Elements for Milling

In the case of the milling process, the rotating speed, the cutting depth and sending speed are very important. These imporatnt elements are affected by the materials, the shapes and the roughness of the surface and etc. Generally, in order to get the high roughness, the cutting depth must be set to small, and the sending speed must be set to low.

If you don't know the values ...

If you do not know the suitable values of the three elements, you should set a small cutting dedpth, a low sending speed and a low rotating speed for safety.

Fig.3, Three Important Elements


Automatic Sending

A general milling machine has an automatic sending mode. This is veru conbenient and to get efficient processing. But it is too dangerous that a beginner may often send the table to the opposite direction. Please use the automatic sending mode after enough experiences.

Procedure of Milling Processing

For an example of the milling processing, a mechanical part is made by the milling machine in followings.


(1) Cut Board Material
A material was cut by a band saw. The size is bigger about 3 mm than the final size.

(2) Cutting of Bottom Surface
The material is cut with the bottomedge of the end mill. In such ways, two face of the material can be cut.

(3) Cutting of Side Surface
The material is cut with the side edge of the end mill. When the vise is set in the vertical position accurately, the material can be get the accurate rectangle easily.

(4) Shaped Part
The material is shaped with the end mill. Since it has a complex shape, we are careful in the processing.

(5) Drilling
The tool is changed from the end mill to a drill.

(6) Completed Part
This is a completed part. It is not so simple shape, but the milling process is not so difficult.
Fig.4, Procedure of Milling Processing

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