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How to Replace Your CO2 Laser Focus Lens

How to Replace Your CO2 Laser Focus Lens

Wang wenting |


What is the focus lens?


In a CO2 laser engraver, the focus lens is a critical component that helps to focus the laser beam onto the material being engraved. The focus lens is typically made from a special optical material, such as fused silica, that can withstand the heat generated by the laser beam. The lens is placed in the beam path at a precise distance from the laser aperture and focuses the laser beam to a small spot size, which is necessary for precise, detailed engraving.
The focus lens can be adjusted to change the focus point and the spot size, which can impact the quality of the engraving. For example, a small spot size will result in finer, more detailed engraving, but will also take longer and require more laser power. Conversely, a larger spot size will result in quicker engraving, but may sacrifice some of the detail.

The consideration for the replacement focus lens

Replacing the focus lens in a CO2 laser engraver is typically necessary due to physical damage, optical degradation, misalignment, and the desire to improve performance. By regularly inspecting and replacing the focus lens as necessary, it is possible to ensure optimal performance and minimize the risk of damage to the laser system.

When considering the replacement of the focus lens in a CO2 laser engraver, several factors should be taken into consideration:
Quality of the lens: It's important to choose a high-quality focus lens that is capable of withstanding the high temperatures and laser radiation generated during operation. The lens should also be made from a material that provides good transmission of the laser beam and minimal absorption or scattering.
Lens diameter: The diameter of the focus lens should match the laser beam diameter to ensure that the entire laser beam can be focused onto the material being engraved.
Focal length: The focal length of the focus lens determines the distance between the lens and the material being engraved, and should be selected based on the size and thickness of the material, as well as the desired spot size and focus quality of the laser beam.
Compatibility with the laser engraver: The focus lens should be compatible with the laser engraver, and the lens mount or holder should match the design of the laser system to ensure proper alignment and performance.
Cost: The cost of the focus lens is an important consideration, as the price of high-quality lenses can vary significantly. It's important to balance the cost with the quality and performance of the lens to ensure the best value for the investment.
In conclusion, when considering the replacement of the focus lens in a CO2 laser engraver, it's important to take into consideration factors such as the quality of the lens, lens diameter, focal length, compatibility with the laser engraver, and cost to ensure that the best lens is selected for the specific application.

Monport CO2 laser focus length

Monport 80w Focal Lens Diameter: 18mm
Monport 150w Focal lens Diameter: 18mm
Focus lenses come in various sizes by diameter and focal distance you can insert lenses with different focal lengths, make sure you get the correct diameter for your lens barrel either 18 or 20 millimeters. Monport machines from 60w to 150w can accommodate 18mm and 20mm focal lenses, so you can completely replace them.


The Steps to Replace Focal Lens

Tools you need

  1. Small adjustable wrench
  2. Flat head screwdriver
  3. A Clean rubber glove


Step 1: Remove the air-assist nose from the head by pushing in the small blue ring and pulling out the hose. Then, unscrew and remove the hose's elbow fitting.

Step 2: Unscrew and remove the laser nozzle from the bottom of the laser head. Put on a clean glove and handle the focus lens with only that hand.

Step 3: Inside the nozzle, unscrew and remove the metal retaining ring that holds the lens in place. Then, remove the plastic o-ring and pop out the focus lens. Clean the lens before proceeding.

Step 4:  Inspect the lens closely for any dust or debris. Once it's clean, place it inside the laser nozzle with the convex side facing up.

Step 5: Place the plastic o-ring on top of the lens to protect it from metal components.

Step 6: Screw the internal retaining ring back into the laser nozzle.

Step 7:  Screw the laser nozzle back into the lens barrel, then screw the elbow fitting back into place and reattach the air assist hose.



The focus lens in a CO2 laser engraver is responsible for focusing the laser beam to a precise spot size, which is essential for achieving high-quality engraving results.
There are usually three steps to replace the focus lens. First, remove the air assist, open the lens barrel, and then replace the focus lens. During this period, you need to wear gloves to prevent secondary pollution to the lens, and then install and reassemble. Follow Monport's steps together to make your machine operate more accurately.