Lens maintenance: After the machine has been working for a period of time, a layer of gray will be adhered to the surface of the lens due to the working environment, which will reduce the reflectivity of the reflective lens and the transmittance of the lens, ultimately affecting the working power of the laser. Maintenance method: Gently wipe the surface of the lens clockwise with a degreased cotton dipped in ethanol to remove dust. In short, we should regularly do the precautions for laser engraving machines, in order to greatly improve the lifespan and work efficiency of our machines.