Fiber laser marking machine is becoming more and more popular in various fields. Because its price is getting lower and lower. And it is very easy to operate. But there are still some people who have a bad experience with laser machines. They may face many small problems or questions, especially focusing on the focus. Many people don't know how to find the focus. Why do you need to find the focus of fiber laser marking machine? The fiber laser marking machine needs to adjust the working size through the lens. The F-θ lens is a convex lens, just like a magnifying glass. We know that it has a focal length from lens to lens. At this length, all light power is concentrated on one point and has high power. The fiber laser marking machine uses this theory to focus all lasers on one point. The laser will leave marks after high temperature. Therefore, the laser marking machine can only work properly when the machine is in the correct focus. This is why we need to find the correct focus before using the laser machine. How to find the focus of a fiber laser marking machine There are mainly three ways to help us find the correct focus. 1. First, we need to find the focus manually. We can put a small metal piece in the working area and select the "Continue" button. Then we need to adjust the laser marking head up and down and check the laser. When a very strong laser acts on the metal surface, it is the focus. This way is the most common way and easy to learn. 2. Measure the length. F-theta lenses of different working sizes have special focal lengths. We can measure the length from the F-theta lens to the workpiece. There are some problems with this way because there may be some errors in the measurement. After finding the focus in this way, we still need to do some fine-tuning. 3. Red pointer outside. We installed an extra red pointer under the laser marking head. There are two points when the machine is turned on. When the two points coincide, it is the correct focus. Now we install it for all machines. It can save users a lot of time.