Advanced Engraving Techniques: 3-D Engraving
WHAT IS THE DIFFERENCE BETWEEN 2-D AND 3-D ENGRAVING?
Almost all rotary engraving machines available today are 2-Dimensional or 2-1/2-Dimensional systems. In 2-D engraving, the engraving cutter is set to a specific depth of cut mechanically by the equipment operator or via software or hardware commands from the engraving controller. The entire job is engraved at the specified depth unless physically reset by the machine operator. For a true 2-D engraving system, there is no automatic way to change the depth of cut during the engraving job. Air actuated Z-axis systems such as older Dahlgren and Newing-Hall systems are 2-D.
"2 ½-D engraving" is a term that refers to the machine's ability to change the depth of cut during the engraving job. During engraving, the system can vary the distance the cutter moves into the material at the beginning of the down stroke of the tool. This allows different parts of the job to be engraved at different depths. There is no variation of depth while the tool is down in the material, only different depths each time the tool enters the material. Thus the user can achieve a "stair step" effect in different parts of the job with different depths in the material. 2 ½-D engraving systems cannot operate the X, Y, and Z axis at the same time to ramp into the material.
In true 3-D engraving, the engraving tool can vary in depth during the cutting process. The engraving system has complete control of all three axes of travel (X, Y, and Z) as required to achieve the desired effect. In most 3-D engraving applications, the shape of the cutting tool is carefully described to the 3-D software. The software generates the necessary tool path to completely rout or cut-out the design at a much higher accuracy and level of detail than is possible with 2-D processes, particularly when the engraving is required to be deep into the material.
For example, if the operator wishes to engrave raised letters into a material .15" deep, the 3-D software will use the cutting tool architecture (its width and shape), to determine the required engraving paths. If the area between characters in the job is less than the width of the cutter used to rout out the final depth, the software will instruct the hardware to raise the cutter enough to clear the characters and complete the engraving. This 3-D cleanup pass results in much sharper engraving definition than is possible with 2-D processes.
Another application of 3-D engraving is to read a gray scale bitmap image such as a photograph and generate a 3-D profile based on the gray level of the bitmap. This allows the operator to scan and engrave pictures as a 3-D relief image into many materials. The Vision-Pro™ 3-D Photomachine allows this type of engraving. It is a slow process, but with practice can yield some interesting results.
ARE THERE DIFFERENT TYPES OF 3-D ENGRAVING?
The 3-D technique most common to the engraving and sign-making market is the 3-D Carve or Edge cleanup 3-D. Programs such as Vision-Pro™, EngraveLab™, Casmate™ and EnRoute™ can do this type of 3-D work. With this process, the software uses the shape of the artwork being engraved and the shape of the cutting tool to determine the depth to engrave. When the tool encounters narrow locations in the artwork, such as serifs in letters, the cutting tool draws itself out of the material so as not to "blowout" the definition of the engraving in this small area. The cutter also draws itself up all inside comers of the job to create very sharp inside edges in the engraving. This creates a very striking effect not possible with normal 2-D or 2 ½-D engraving techniques.
Some users think that the process described above is not "true 3-D" since these software programs cannot generate a true surface. This is not really the case, since these programs do instruct the cutter to move X, Y, and Z-axis together, to complete the engraving. This is 3-D engraving, just not the upper end of the 3-D spectrum.
More advanced and more expensive software programs can generate complete 3-D surfaces. The user can scan artwork and instruct the software to automatically create a 3-D embossed surface from the scan. This is used in die and mold making, as well as other advanced applications requiring a complete 3-D surface. If the customer has a need for this process, there are ways to achieve the results even with a less sophisticated 3-D package.
AT THIS TIME THERE IS LITTLE COMPETITION FOR 3-D ENGRAVED PRODUCTS, AND THE ABILITY TO PROVIDE THESE ITEMS CAN GIVE YOUR SHOP A DISTINCT ADVANTAGE IN THE AWARDS AND INDUSTRIAL ENGRAVING MARKETS. SOME OF THESE INCLUDE THE FOLLOWING:
- High quality 3-D engraving for acrylic awards.
- 3-D photo machining of photographs on acrylic, wood, and other materials.
- Small 3-D sign-making (some work currently done with small sign routers)
- Injection mold die-making and other mold making processes.
- Lost wax mold-making for jewelry manufacturing applications.
WHO WOULD WANT TO USE THIS PROCESS?
- High-end awards retailers that are looking for a new look or new product to offer their customers.
- Many types of industrial engravers that need 3-D engraving capabilities for relief die- and mold-making, and other specialized engraving applications.
- Injection molding companies looking to replace chemical 3-D etching processes with 3-D engraving for their business.
- Anyone looking to the future that wants an engraving system that they can add this important process to in the future as their business grows or changes.
ARE THERE ANY SPECIAL HARDWARE OR SOFTWARE REQUIREMENTS?
Beyond the need for a 3-D capable engraving system, the user would need the following:
- A fairly powerful engraving system with enough memory to compute 3-D tool paths efficiently.
- An engraving table and associated electronics that has a "true" motorized Z-axis. Unfortunately, air-driven systems cannot do this kind of work.
- A compatible 3-D engraving software to generate 3-D tool paths. Vision-Pro™, EngraveLab™, Casmate™ and EnRoute™ offer 3-D options to generate the 3-D carve type of engraving. Vision-Pro™ and EngraveLab™ also offer the 3-D Photomachine option with their 3-D package. Higher-end packages such as Cimigrafi™, ArtCAM™, SmartCAM™, or one of the other high-end Computer Aided Manufacturing (CAM) packages are needed to generate true 3-D surfaces for engraving.
- A compatible graphics creation program such as EngraveLab™, Casmate™, or CorelDRAW™ to generate artwork to use to create the 3-D tool paths from. This is required when the 3-D tool path generation program does not offer the drawing tools to create the artwork in their own package.
WHAT KINDS OF TOOLS ARE NEEDED FOR 3-D?
Depending on the desired effect, the only tools required would be some additional engraving cutters sharpened specifically for 3-D work. Most 3-D work can be done with the same engraving tools used for normal 2-D engraving. For 3-D engraving into hard materials such as metals, a collet spindle is recommended for the highest quality engraving.
If you plan to do work in wood or in sign materials, several sizes and architectures of router bits may be used. Again, they can be used if you have a collet type spindle.
3-D engraving is not really complicated and can be done by many of today's engraving systems; however, it's also not for everyone. If you have the hardware to support it and the customer base yearning for fresh products, then 3-D is definitely worth serious consideration. Part of your future plans should include providing new and innovative awards to your customers. If you don't, the competition will.