Why is it a good idea to buy a second-hand CNC milling machine? What are the advantages of this type of machine tool? What does it offer the machine shop and its operators? With a used milling machine equipped with CNC technology you can save considerably compared with buying a new machine.
What is a second-hand CNC milling machine?
Milling machines are among the most widely used machine tools in machine shops and, in recent years, those equipped with CNC technology have been the most in demand. Milling machines are conventional machine tools that perform various metal-cutting machining operations.
To do so, they use a cutting tool with one or more cutting edges, called a milling cutter. The cutter rotates and approaches (or not, depending on the machine) the surface of the workpiece. As it does so, material is removed in the form of chips.
Today there are different types of milling machines in industry. They are classified by tool orientation (horizontal, vertical), by number of axes (three, four or five axes) and as special machines (gantry milling machines).
What is numerical control?
A second-hand CNC milling machine is a type of machine tool that incorporates CNC technology. In other words, it is equipped with a main computer that runs the various programs and operations the machine can perform on a workpiece. It determines which cutting tool to use, its speed, the depth of cut and so on.
For a second-hand CNC milling machine to work properly, an operator first has to design the part on an external computer. The design is then loaded into the milling machine's computer. The machine works using an alphanumeric system (letters, numbers and symbols) that is programmed (automatically or manually) to carry out a specific job.
CNC machine tools of this kind are among the most advanced in the machining industry. They require hardly any operator intervention; the machine itself selects the machining parameters and also repositions the workpiece (if necessary) or changes cutting tools. To this end, the milling machine has a tool magazine that can hold a large number of cutting tools. The machine switches between these tools as required to perform the necessary operations.
Why buy a second-hand CNC milling machine?
CNC is one of the most pioneering technologies available today and, being among the most advanced, it is also the most expensive. Why does a CNC machine cost more? Bear in mind that conventional machines do not have a computer as CNC machines do; consequently, the electronic components of the latter make them more expensive.
A CNC machine is a sound purchase as long as it is used intensively in the workshop, because in the long run it allows you to recoup its cost. And is it a good idea to buy the machine second-hand? You may be surprised to learn that companies selling second-hand CNC milling machines recondition them and set them up before delivering them to the customer.
A used CNC milling machine lets you save a great deal, as its price has already depreciated and the investment will not be as large as for a brand-new machine; moreover, as mentioned above, used machines are delivered fully refurbished, inspected and with the corresponding quality marking. You will also have specialist technical service able to train your machine shop operators, and you will find spare parts and components much more easily in the event of a breakdown.
The benefits of CNC machining
Besides the benefits that buying a second-hand CNC milling machine can bring, simply acquiring a CNC machine offers a number of advantages for the workshop. Numerical control is very easy to use, although it requires an engineer capable of designing parts on a computer. However, once this is done and the design has been loaded into the machine, a single operator can work simultaneously with several machines of this type.
CNC also has the benefit of lowering production costs and shortening lead times. This is because a computer numerical control milling machine can work at high speed and produce parts in series. Moreover, since the machine has a tool magazine that changes the cutting tools, the operator does not need to stop the machine to change tools; the CNC milling machine does it automatically.
Finally, if the workpiece needs to be repositioned for another operation, the machine tool itself will move it into the most suitable position without stopping production.