Laser Engraving Machine
Laser Engraver: Guide to Engraving Curved Surfaces
Laser engraving machines can not only engrave flat materials, but also for curved objects, even irregular shaped objects, such as natural stone. You can use a laser engraving machine to engrave patterns on any curved surface, it’s so easy! As a professional in the EMIT Laser machine manufacturer, I will give you some guides on curve engraving so that you can freely engrave your creativity.
How to adjust the Focal Length for Curved Surfaces?
Basically, when processing materials with a laser engraver, it is necessary to measure the focal length using a flat material. EMIT laser engraver’s LaserPro series is very easy because you can use an autofocus pin and measure at the push of a button!
However, when engraving on ballpoint pens or glass cups, the material itself has an R (curved surface), so the focus deviates during processing.
Of course, if the focus shifts, the processing quality will be affected. So how long is the focal length? I will verify it.
Laser engraving with a focal length of 0-5mm
What is the effect on the processing quality by trying to increase the focal length of laser engraving machine from 0mm to 5mm?
This time, we used MDF material that makes it easy to understand the changes. If you look at this picture, you can see that the characters are blurred as the focal length increases.

Processing quality and focal length
The blurring caused by the focal length is related to the mechanism of the laser processing machine. The laser beam has the same structure as a science experiment where you burn black paper with a magnifying glass.
(Sunlight = laser beam, magnifying glass = focus lens, black paper = MDF (material))
In other words, changing the focal length increases the diameter of the laser.

In the photo, the characters are blurred from around 3 mm, and the quality of laser processing has changed.
Therefore, if the focal length is around 2mm, you can engrave without changing the quality.
If you change the material, there will be a slight difference in the distance at which it looks fine, but any material can be sculpted finely up to a focal length of approximately 2 mm.
By the way, there is an optional product called “Rotary attachment” for processing cylindrical objects.
- Rotary attachment: A special device used when laser processing cylindrical objects.

- Attach the rotary attachment to the laser engraving machine.

- Paste the masking tape and engraving.

There are different sizes of rotating attachments, and you need to choose according to the diameter of your engraved object. Each machine of our company can be equipped with additional rotating attachments, and you can customize it according to your actual needs.
If you have any question about engraving curved surfaces, please feel free to contact us.