What Is CNC Engraving?
CNC engraving is a subtractive manufacturing technique that involves the gradual removal of a certain amount of material from the workpiece surface along a predetermined path. The CNC engraving machine produces desired visible markings on the workpiece’s surface by making shallow cuts to machine fine details. You can use this machining process to add information such as personalizing texts, serial numbers, measurements, markers, or alignment points in mechanical items.
It is a modern method of engraving that relies on computer numerical control technology to guide the engraving tool to achieve the utmost accuracy and precision control. Product teams across different industries employ engraving machining in various applications, especially for decorative purposes.
Understanding the CNC Engraving Process
To achieve the best results from the CNC engraving process, it would be best to understand how the process works. How the engraving process works is as follows:
The first step in the CNC engraving process is to create a visualization or design model of the engraving pattern with CAD software. It is crucial to fully understand the computer-aided design software package to efficiently generate complex patterns with high accuracy.
CAM (computer-aided manufacturing) software is a unique software product designers/engineers use to create programs for the CNC engraving machine based on the CAD design.
The engineer depends on this software to choose appropriate tooling for the engraving operation, process parameters, and program tool paths. Most especially, the CAM software produces a G-code file containing a language the CNC machines can understand.
A machinist sets up the workpiece in the CNC engraving machine before the process begins. Here, the machinists position the workpiece appropriately to avoid machining errors.
The CNC technology reduces human input during the engraving process. The process involves using a CNC router to cut material away from a workpiece along a defined path to achieve the preferred shape or design.
Types of CNC Engraving
Machinists often utilize different CNC engraving techniques in cutting different patterns and texts into surfaces of different CNC machining materials. Although these engraving processes may offer similar results, they differ in specific ways. Common types of CNC engraving include:
Diamond Drag Engraving
As its name implies, this process involves dragging a diamond tip with sharp edges across a workpiece’s surface to create desired markings. Diamond is a reliable engraving tool since it is the hardest known material. Besides, the diamond drag engraving method doesn’t require tool rotation. As a result, scratching is the primary process for cutting material from a surface.
CNC diamond drag engraving delivers excellent precision control over the movements of the tool, ensuring highly accurate and quicker operations. This process is ideal for engraving the hardest metals due to the diamond’s superior hardness.
CNC Rotary Engraving
This CNC engraving process removes material from the surface of the substrates using rotating cutters. The rotary engravers have cutting edges in the form of flutes and are somehow similar to a regular machining tool.
A unique spindle holds and spins the rotary engravers in the CNC engraver. CNC rotary engraving is a high-speed method with speeds up to 20,000 RPM. Besides, it has a cut depth range between 0.5 – 3mm based on the material properties of the workpiece and design demands. Consequently, these capabilities render CNC rotary engraving highly versatile, cost-effective, and compatible with different materials.
CNC Laser Engraving
CNC laser engraving is a popular method that uses a high-intensity laser beam to heat the surface of a workpiece to a point where it sublimes, leaving an indentation. Laser engraving machines feature a laser head that generates the laser beam that melts the workpiece’s surface. This process is swift and precise since the laser head’s movement is CNC-controlled. More importantly, the laser’s engravings are reliable and have an extended lifespan.
However, it would help to know that laser marking, laser engraving, and etching, even though they may offer similar results. Laser marking provides a lower indentation depth compared to laser engraving. Similarly, laser etching is a different process that involves using chemical reactions to material from the substrate’s surface.
Materials Suitable for CNC Engraving Machines
CNC engraving machines are of different kinds, each with distinct properties and capabilities. These CNC engravers can machine various machining materials irrespective of the application. Common materials these engraving machines can work with include:
Metals
Generally, metals are the most popular material a CNC engraving machine works on. Metal engraving is a less intense form of CNC milling. You employ the same cutting parameters and types of CNC cutter When engraving metal.
A CNC milling machine functions as a CNC engraving machine at a stage in its operation as a laser engraver aims to engrave the surface of metals rather than cut it. The same applies to CNC routers commonly used in engraving patterns and making 3D parts with intricate designs.
Nevertheless, metals are difficult to engrave and may require sophisticated tooling such as coated cutters. As such, engraving metal is more expensive than engraving other materials like plastics. A CNC engraving machine can engrave metals like gold, silver, copper, aluminum, brass, stainless Steel, and mild steel. Aside from these common metals, titanium alloys are harder metals compatible with engraving.
Besides, hardness is one of the most critical properties to consider in CNC engraving as it helps determine how difficult it is to deform its surface. Hence, an expert opinion is to consider using spring-loaded diamond or high-performance engraving cutters for extremely hard materials.
Plastics
CNC engraving machines are efficient when it comes to engraving plastic materials. There are extensive polymers that are compatible with CNC engraving. These include ABS, nylon, polyurethane, polyethylene, polyamide, and polystyrene. Most especially, thermoplastics are more suitable for engraving machines because they show excellent thermal stability than other plastics.
CNC laser engravers and rotary engravers are suitable for making patterns and texts on the surface of plastic materials. However, laser engraving is the more popular choice when engraving plastics since it is very fast, accurate, and requires low maintenance.
Although engraving signs on plastics can be easy, machining flaws such as burrs occur, causing them to soften due to heat from cutting. However, you can effectively manage these challenges to achieve excellent results, such as increased productivity.
Wood
Wood engraving offers a range of artistic applications, including gifts, luxury items, and home decor. Wood is a natural, soft, and economical option among the materials compatible with laser and CNC rotary engraving machines. Common types of engravable woods are cork, balsa, birch, softwood, and hardwood.
However, it would help to note that wood is anisotropic, and its properties are not uniform in all areas. They may vary with knots, growth rings, and grain orientation. As a result, consider these when determining the suitable wood for your engraving projects.
In addition, oil and moisture content can hinder the effectiveness of laser CNC engravers. Likewise, be careful of wood dust when using a rotary CNC engraving machine.
Cost Factors in CNC Engraving
Several factors contribute to the cost of CNC engraving processes. Below are some of them:
Material Selection
The chosen material for the CNC engraving process is a significant machining cost determinant. Various materials with a hard surface are unlike softer materials because they often demand special tools, which adds to the cost of engraving.
Design Complexity
The complexity of your engraving design or pattern can influence the overall costs of the process, as intricate designs may require longer programming time, slower feed rate, and special tools.
Tooling Costs and Machine Maintenance
You may need specialized tools that are expensive to execute some engraving tasks. Consequently, tooling costs may increase significantly if the design demands special tools or consistent tool changes. Also, periodic maintenance of engraving machines for efficient performance influences the cost of the engraving process.
Tolerance and Surface Finish
CNC engraving may require high-precision machining to achieve tighter tolerances and superior-quality surface finishes to meet the stringent quality requirements of particular applications. As such, it may become costly because you have to use a slower cutting speed and additional surface treatment.
Advantages of CNC Engraving
Considering the fact that CNC engraving is a widely used process in various industries, you would agree that it offers immense benefits. Here are some of the common advantages of CNC engraving:
Customization
Since these engraving machines use CAD/CAM software, product teams in different industries achieve easy customization of CNC parts and components with the desired design and text. Likewise, the process allows you to make immediate modifications to your CAD design during the process.
More so, CNC engraving offers excellent high efficiency in CNC machine shops specializing in rapid prototyping or handling many projects simultaneously. The process helps to efficiently mitigate errors or change to a different design, optimizing productivity.
Higher Precision and Accuracy
The CNC engraving technology offers high precision and dimensional accuracy since a computer controls the process. The CNC engraving machine can engrave signs with about +/- 0.0025mm tolerance. The high level of this process makes it a perfect choice for various applications requiring engraving.
Time Efficient
Manual engraving used to be time-consuming and laborious because artisans commonly used hand tools and depended on human skills to operate. However, modern CNC engraving machining is a fast and automated process. As a result, it creates CNC engravings much quicker and meets design requirements.
Applications of CNC Engraving
CNC engraving is highly versatile and provides excellent results in different applications in several industries. The most common applications of engraving include:
- Industrial Marking
- Sign Making
- Awards and Trophies
- Jewelry and personalized items
- Architectural elements
- Woodworking
- Automotive parts
- Aerospace components
- Medical devices
Choosing the Right CNC Engraving Service
Choosing the right CNC engraving service experts for your project is crucial to achieving excellent results. You can choose from the different engraving techniques to add vital details and descriptions to your parts. However, choosing a CNC shop with the right engraving machines and expertise is advisable to effectively handle this secondary manufacturing operation.
AT Machining is your best bet whenever you need a top CNC machining services provider. We specialize in various CNC machining processes, including CNC engraving, milling, turning, drilling, etc. Our certified engineers and technicians have years of experience machining high-quality CNC engraved parts. Submit your CAD files today for an instant quote!
Conclusion
CNC engraving is an efficient solution for modern manufacturing industries, providing vast capabilities and applications. It allows you to make desired artistic markings, signs, or patterns on machined products made with metals, wood, plastics, or other solid materials.
As such, product designers in various industries continue to rely on engraving to make accurate and precise shapes and designs on the surface of machined parts.
FAQs
How Does CNC Engraving Differ from Laser Engraving?
The CNC engraving technique uses sharp cutting tools to remove material from a workpiece held and secured in a position. The process can only engrave one part at a time since the cutting tool needs to reset for the next part. In contrast, laser engraving utilizes a high-power laser beam to heat a workpiece’s surface to vaporize desired material off its surface. The workpiece doesn’t need to be fixed here since it is a no-contact process.
What Are the Common Cutting Tools Used in CNC Engraving?
The V-bit cutter with a solid carbide tip is the standard CNC engraving cutter. Full carbide cutters are another common choice. Diamond-tipped cutters are suitable for more rigid materials, while ball-end mills are your go-to option for working with a rounded surface.
