If you're marking on slanted or curved part surfaces, you may think that you need a 3-axis laser system. After all, traditional 2-axis, or 2D, laser marking systems can only mark on a single plane, right? The truth is, 2D laser markers are capable of much more than you think.
The best way to determine the most appropriate laser marking system for your application is to understand these technologies. Here is MECCO’s quick guide to help you learn the basics.
Overall, laser engraving and marking is a solid choice for a range of applications and creates clear, easy-to-read identification on parts. With the wide variety of part geometries, different laser technologies have been developed over the years that offer a variety of methods to accomplish the range of marking needs.
A laser’s scanhead controls its ability to mark single or multiple planes of a part’s surface. There are two options on the market: 2D and 3D laser marking systems. These two dimensional and three dimensional laser scanheads use a corresponding number of axes to focus the laser beam for marking. Therefore, they are also referred to as 2-axis and 3-axis laser systems.
The difference is that 2-axis lasers typically mark on one plane of a part, while 3-axis scanheads can mark on a 3D contour.
The 3-axis laser scanheads have been around for about 20 years, and their ability to change focal distance quickly, compared to a linear stage that moves the laser up and down, is appealing for those wanting to mark over areas of a part that have odd contours and slants.
The typical applications that make use of the quick-changing focal distance are more commonly referred to in the industry as 2 ½ D. This is because the laser marks two or more planes on a part, and thus, it is not fully taking advantage of the 3D capabilities.
Imagine a set of steps on which you need to mark each step’s top side. Instead of having to move the actual laser up or down on a Z axis, the 3-axis scanhead can quickly change focal distance to each step.
However, the ability to quickly change focal distance comes at a great price. The 3-axis laser scanheads are much more expensive than traditional 2-axis scanheads, and they’re limited to just +/- 21mm of adjustment. Therefore, it's best to ensure that the additional focal distance functionality is appropriate for your marking application before drastically increasing your cost.
Most marking applications on flat, slanted, or curved surfaces can actually be performed with a 2-axis scanhead with the correct lens.
How? Often, a large field lens with a greater depth of focus, like a 330mm or 420mm, can be utilized to successfully mark parts that seem to require 3-axis. The added benefit is that a 2-axis scanhead doesn’t use any moving parts to accomplish the marking, so it requires less maintenance.
Only 5% of laser marking applications require 3-axis lasers, meaning that it is quite the exception that you could justify the higher cost.
That’s why it's important to partner with a manufacturer that seeks to understand your needs and engineer a solution for you. At MECCO, we optimize our laser marking machines to accommodate the requirements of your application. As experts, we understand how best to utilize laser, scanning, and lens technology to provide the most robust and efficient system.