The focusing lens of laser cutting machine is a relatively sophisticated optical component, the cleanliness direct affect the processing performance and cutting quality of the laser cutting machine. So the regular maintenance of focusing lenses is very necessary, following is the proper operation:
1. Take out the lens from the focusing mirror bracket: Loosen the fastening screws, take down the gas nozzle and the lens barrel in proper order; blowing the dust on the lens surface by the balloon;
2. If the lens need to be cleared, must use the laboratory use soft cotton ball, dipped in acetone or alcohol with high degree, then awhirl wipe the lens gently and clockwise from the center to the edge. If necessary, both sides of the lens need to be cleaned; and the clearing should be careful and meticulous;
3. Install the lens barrel and gas nozzle, adjust the focal length, tighten the fastening screws, finished the installation of focusing lens, and be sure to keep the convex side down.

The maintenance of focus lens should pay attention to the following three points:
1. The material of focusing lens is ZnSe (zinc arsenic), more brittle, so must prevent to be thrown when disassemble it, and avoid to be crashed with hard object. The surface of the lens with antireflection film, which is easy to be contaminated and scrapped,  so the operating must in the dry, and oil free air, and do not handle the lens directly with hands, for the grease on hand will permanent damage to the lens surface. Oppositely, the clearing should be finished with some gloves and special tackling, and for smaller lenses, optical tweezers or vacuum tweezers are more convenient. No matter what method you use to clip the focusing lens of laser cutting machine, the only ways is to be clamped along the non-optical surface, such as frosted edges of the lens.
2. Generally, the lens should be checked before using, before and after cleaning. Because most of the contaminants and surface defects are very small, so the magnify equipment should be used when examining the lenses. In addition to the enlarging equipment, sometimes we need some brighter beam of light to illuminate the optical surface, to enhance the specular reflection of surface contaminants and defects, making it easier to be found.
3. When cleaning a laser cutting machine focusing lens, we often use some clean wipe paper and optical use solvent to prevent damage by other pollutants. The wipe paper must with suitable solvent and to be wet. For the consideration of softness of the materials, the clearing paper should be made of cotton, or use the cotton ball and lens paper.
The focusing lens of the laser cutting machine are easy wear parts, if it was cleared for some times but still cannot reach to the requirements, it should be changed, to ensure the laser cutting machine processing efficiency, so as not to delay the production.