CNC engraving
When the machine learns to write.
Those who rely on long-term labelling and illustration use CNC engraving for precise and long-lasting results. In the industrial sector, the handling of machines is secured by instructions on switch cabinets, for example. These should not be applied using imprints or adhesive films, especially when working in chemically aggressive environments.
Special features
What you need to bear in mind for CNC engraving
Speed
and accuracies
With milling engraving, speeds of 8 to 12 metres per minute and an accuracy of around one millimetre can be expected. The material can also be cut and otherwise milled into shape. For other processes, such as laser engraving, these values depend primarily on the heat resistance of the materials. Roughly speaking, they are between 10 m/min and 100 m/min.
Engraving depth
Depending on how deeply the surface can be penetrated, CNC engraving can achieve very precise results in every layer. Deep engraving with laser technology in particular is a tried and tested means of engraving acrylic glass, even within the workpiece. It can also be used to achieve and visualise different colour layers in multi-layered engraving materials.
Engraving lines and labelling
Different CNC engraving processes offer different degrees of precision for engraving lines and labelling. Choose a process that suits your application and with which you can achieve your goals most economically. In order to determine the optimum concept, our experts offer you support in a consultation.
Materials at
CNC engraving
From wood to glass, stone and metal, virtually all materials that are suitable for CNC machining can be processed. Metals, for example, are milled and then burnished for multi-coloured results, and stainless steel can also be engraved using CNC engraving. Sandblasters are sometimes used for stone materials such as marble or granite.
Angle for engraving cutter
The gravers should always have a point grind so that they do not break away during engraving. Different point angles are required depending on the engraving depth and material of the milling cutter or workpiece. Either no angle is required at all for scribe engraving with gravers or tangent values are calculated for milling heads based on depth and graver diameter.
Maintenance, cleaning
and cooling
The maintenance requirements of a CNC machine with engraving technology are no greater than those of a machine concept used to machine workpieces in moulds. These are actually the same tools, which are either operated with a different programme or a different setting. Therefore, there is no change in cleaning and cooling, for which certain nozzles - depending on the material - are required.
FAQ
Answers to the most frequently asked questions about CNC engraving
For engraving, it may be sufficient to use a so-called pantograph, which is controlled by a lever. Ideally, the engraving machines have CNC technology and several axes. This allows the machines to be used flexibly. The concept envisages use as a CNC milling and engraving machine.
The CNC machine can even be converted into a CNC 3D printer in no time at all by changing it with suitable tools. So-called portal milling machines with up to five axes ensure high efficiency in workpiece machining and can produce very complex geometries in a small machining area. This dynamism and adjustability of the milling tools is particularly important for the production of embossing tools.
If the machine is used for different applications, machine downtimes are prevented, the costs per system are reduced and the production chain is streamlined. The latter is due to the fact that engravings can be applied to the same component directly after mould milling.
In certain cases, the machine is equipped with a template and a process route is transferred manually. However, in addition to CNC machines, tried and tested methods are still used for engraving today. These include, for example, the hand grinder or needle embosser. CNC technology is a very young process in the field of engraving and in a historical context, and has only made great progress since the last century. After industrialisation in the 19th century, many manual engraving techniques, some dating back to antiquity, were mainly used for marking.
For example, various CNC engraving techniques are used for the labelling and illustration of trophies. Often, engraving technicians still work with a hand-held Dremel, as the engraving on a trophy for the winning team is decided right next to the pitch - most machines are currently not compact enough for such applications.
However, thanks to technical advances in CNC engraving, bulky and cylindrical pieces can now be processed very easily and efficiently. Nevertheless, programmeless engraving is easier in certain situations and for some bulky workpieces. In this case, the machine is aligned manually by engraving along a template. From an economic point of view, this is not suitable for series production and templates must first be created in an additional work step.
Otherwise, the possible applications are very extensive. From lithophanes, photorealistic 3D prints in acrylic glass and plastics, lighters and belt buckles to front panels and control cabinets. Both in the private and industrial sectors, CNC engraving is popular wherever motifs and lettering need to be permanently captured.
Acrylic and Plexiglas are frequently engraved in industry - we have more information on this for you under Plexiglas engraving.
Due to their chemical properties, CO2 lasers ("carbon lasers") can only be used on organic materials. Diode lasers work with a specific wavelength of the laser beam and are ideal for metalworking. The surface is either discoloured with a bundled beam of light or vaporised at micro level. It is possible to carry out deep engraving and 3D engraving with such laser heads. However, diode lasers really come into their own in CNC engraving when signs and surfaces are to be provided with logos, symbols or lettering on a purely superficial level.
The machine concept with a CO2 laser is completely different here, as large processing surfaces are used for deep and long engraving sections. With the carbon laser, signs can not only be labelled, but also punched and cut. It is therefore possible to use this CNC engraving process to produce both contours and patterns on the workpiece at the same time.
Which programmes and settings a CNC machine requires for engraving depends first and foremost on the CAD/CAM software. Ideally, the machine concept takes into account a lean production chain so that all data and milling routes are transferred to the workpiece using the same software - both the mould milling and the engraving. If different programmes are used for these steps, a different software solution may be required for the CNC engraving machine.