In this article we will try to illustrate in a clear and exhaustive way the operating principles of milling machines and their professional, craft and hobby applications.
What is the milling machine
The milling machine is an electric tool that can come in different forms, depending on the intended use for which it is designed, but is substantially similar to the drill in that it consists of a motor connected to a spindle, on which the chuck is located. allows you to mount different types of tips.
The milling machine owes its name to these tips, which are called cutters due to their particular shape, similar to a small strawberry.
Even if the operating principle is similar to that of the drill, the milling machine stands out for its greater versatility of use.
The distinctive feature of a drill, in fact, is that it can make holes in any type of material; the cutting action, therefore, is concentrated only on the tip of the interchangeable tools.
The cutting action of the cutters, on the other hand, is concentrated on the lateral part of the interchangeable tools, removing material from the workpieces at each passage of the machine; and it is precisely for this reason that milling machines can be used for various applications on an equally wide variety of materials, depending on the type of machine and the type of cutter mounted on the spindle.
The types of machines and possible applications
If you can only drill holes with the drill, you can also trim and groove with the milling machine, you can make slots, continuous pockets and moldings.
In carpentry, just to give a practical example, the milling machine is used to dig the grooves and pockets for the joints of the pieces of wood, to obtain the edges of the same with a high degree of finish, and to create the moldings of doors, doors and fixtures, to perform drilling and even boring.
The same processes can also be performed on plastics and non-ferrous metals, simply by using the specific cutters for these materials; in addition to carpentry, therefore, the milling machine also finds applications in carpentry and mechanics.
They are also widely used in the hobby field by DIY and DIY enthusiasts, in fact the best-selling milling machines are precisely those that fall into this specific market segment. The most common types are vertical milling machines, horizontal ones and so-called routers.
In vertical milling machines, the motor-spindle unit is positioned vertically, so as to work mainly on the surface of the pieces, and on the sides only if the work to be performed is limited to trimming or shaping the edge.
This type of milling machine is usually equipped with two side handles, to allow the operator to move the power tool more or less freely on the piece, which must be fixed to the bench and remain immobile while it is being worked.
The same goes for horizontal milling machines, which however have a different structure as the motor-spindle unit is mounted horizontally.
The horizontal models, in fact, are specifically made to work on the sides of the piece instead of on the surface, in order to create slots, grooves and pockets for the joints.
Also in this case, therefore, the piece must be fixed to the workbench so as to remain immobile while the operator moves the milling machine back and forth.
Routers, on the other hand, are small milling machines that are mainly used for edge trimming.
The micro milling machine
This particular type of milling machine is used both professionally and as a hobby, but the definition of micro milling machine is due not so much to the overall dimensions of the machine, which structurally speaking remains a stationary bench model, as to the diameter of the cutters it uses, which goes from 1 to 3 millimeters.
Micro-milling machines are therefore mainly used for high-precision machining on small pieces of metal, wood or plastic.
In the professional field they are used in goldsmiths, for example, for the processing and decoration of jewels, or to make components and pieces used for mechanics and precision engineering.
In the hobby field, on the other hand, micro-milling machines are mainly used by the most experienced model makers.
Given their nature, they are decidedly expensive compared to the other types described above and, depending on the model, the cost can vary from 350 to 950 euros and more. Also the interchangeable burs, being of the specialist type, are more expensive than the standard replacement burs.
CNC machines and industrial applications
The industrial applications of the milling machines are actually the same that are usually performed also in the artisan and hobby field, with the difference that the level of precision and the extent of the machining are much higher.
Unlike vertical and horizontal milling machines and routers, which being manually operated only work on three axes, industrial milling machines are integrated into a larger system called a machining center, which is capable of working on four or more axes.
A typical machining center consists of a milling machine mounted on an articulated arm, in turn connected to a base and controlled by a CNC machine, or computerized numerical control, and therefore can do without the human operator; by setting the working parameters through the computer software, in fact, the milling machine will work in full autonomy and with a level of precision in the order of microns.
The machining centers are therefore able to perform not only the standard processes described in the previous paragraphs, but also decorations and sculptures of extreme complexity quickly, efficiently and above all extremely precise. They are also used in prototyping, i.e. in the serial processing of identical pieces.
Thanks to technological development, however, CNC machines have recently begun to be used at an artisanal level; with the aid of a simple laptop and specific software, in fact, even a small laboratory can set up a fully automated workstation, for this reason many of the vertical and horizontal milling machines and routers currently on the market in the hobby market segment are designed to be connected to a mechanical arm or to a similar multi-axis control structure, easily manageable by computer.