When engraving curved surfaces, laser engraving machines generally use auxiliary systems, such as rotation aids, so that cylinders such as bamboo tubes, wine bottles, and bird cages can be engraved. In addition, there is another kind of surface that is irregular and uneven. You can choose a laser head that can automatically adjust the focal length to work. Now laser engraving machine manufacturers have been able to produce laser heads that automatically focus on metal and non-metal materials. This makes surface engraving possible.