CNC Machines from Germany for industry, business, education and hobby

Practical use of CNC machines

In the area of metal and wood processing industries CNC controlled machines have long become indispensable. Even in the leisure sector smaller hobby CNC machines are on the rise and allow their owners a simpler and faster implementation of new ideas. The first question that arises is: What makes a CNC machine become a popular tool?

How do CNC machines work?

CNC machines are computerized machine tools that are capable to produce precise and extensive workpieces fully automatic! This requires a modern control technology.

Often, a so-called CAM system is used. It is able to convert the data of a CAD program, which usually designes the components using a postprocessor, in a CNC program. Of course, certain factors must be considered, such as:

• speed
• feed
• tool

CNC machines are equipped with one of these three control types:

• PTP-control
• Link control
• Path control

The latest CNC machines may have more than six processing axes: the main axes X, Y and Z and the auxiliary axes A, B and C each represent a rotation around the main axes. Three-dimensional workpieces can be realized in a very short time.

Programming CNC machines

Nowadays on most CNC machines little or no programming is required. However, manual programming of a CNC machine can be beneficial in correcting small errors.

The conventional textual programming requires manual entry of path conditions, the G functions and the additional functions, called M functions. These were standardized as ISO 66025 for all CNC machines and are commonly used with the G-code name according to DIN / ISO.

This manual input or programming is completely unnecessary today. Modern CAD / CAM systems replace the textual programming by a graphical, workshop-oriented CNC programming. So, the designer simply draws the desired workpieces within the CAD program that converts this drawing into a finished CNC file. Subsequently, the computer-controlled CNC machine moves as programmed processing the workpiece.

Since it is now even possible to integrate a quality control in the manufacturing process, is no more need for constant supervision of CNC machines. The tool wear is monitored fully automatically.

Two ways of measuring the travelled distance

Any conventional machine can be extended by using standardized components to a CNC machine. It is important to keep in mind that with conventional milling machines, the backlash between the machine spindle and the spindle nut is compensated by the operator and by climb milling. Modern CNC machines are equipped with drive systems with ball screws or linear drives, which are virtually free of backlash. This also makes synchronous milling possible.

CNC machines measure the distance travelled in two ways :

• The direct travel measuring system – A glass scale measures the position directly on the moving axis.

• The indirect travel measuring system – The rotation angle of the ball screw is measured this implies the linear axis position.

A so-called PLCA functions as link between the physical machine and the movement control. A program is stored by the manufacturer that guarantees the function, of example, operating modes, safety door, coolant, lubrication and other aggregates. It serves as a linker and primarily determines the machine’s capabilities. Therefore, it remains unchanged even after delivery of the machine.

CNC Machines from CNC-STEP

Which fields make use of CNC machinery?

• Automotive Industry
• Aircraft industry
• Mobile communications
• Toy industry
• Metalworking industry e.g. for the production of washing machines bicycles machine parts
• Modelling
• Architecture
• Wood Processing Industry e.g. wooden toys, candle arches, Crests
• For dosing e.g. applying adhesive
• For placing
• Processing of granite, marble for producing busts, figures, monuments, grave stones, plaques
• Jewellery industry
• Plastics Processing Industry
• Dentistry for implants and inlays
• Orthopedics for reproductions of intervertebral discs
• and much more

Price of a CNC machines

Here you could give a simple answer:

Prices range from about five hundred euros to several hundred thousand euros.

Much more important than the price are your wishes and requirements. The more precisely you know what you require to be satisfied, the more accurate a suitable offer can be made.

The most important criteria when buying CNC machines:

• Locate an authorized dealer – A milling machine should always be purchased from an authorized dealer. Only a fully-trained sales staff can suggest an appropriate model to meet your requirements.

• List your requirements – As individual as your wishes can be, as individual should be the given advice, because the more precisely your milling machine is tuned to the key points, such as size, performance and workpiece to be machined, the better milling results you will achieve later.

• Make sure not only the price is good but also the service is unbeatable – A dealer should offer you free support even after purchasing a machine so that the entry is easier and cheaper. He should also advise you adequate and understandable as a CNC beginner and maybe even offer a free demonstration to facilitate the entry and the purchase decision.

• Attention with DIY hobby homemade CNC milling machines – With reasonable price attracted customers buy unusable CNC machines sold without any warranty and important securities such as valid CE declaration and current EMC testing. Please refer to our contribution about “Rip-off when buying a CNC machine.”