laser marking on green cylinder

How to Mark a Curved, Cylindrical, or Multiple-Plane Part with a Laser

To produce top quality permanent marks, laser marking systems must be focused on a specific point. If your part is flat, then marking will be easy. If your part has a curve, angle, or multiple planes, however, you will need to change the focus of the laser.


There are three options for marking irregular parts:

    • You can change the focus manually by measuring the distance between the laser and the part. Then, adjust the focus by hand.
    • You can use a programmable Z-axis tool post that can be programmed to automatically move when needed.
    • You can use optics to change the focus on-the-fly.


While the first two options will produce a permanent mark, they require time and effort to achieve quality. The best and the fastest method is to use optics. The lens’ mechanical movement inside the laser cavity changes according to the parameters of the part.

How Variable Focus Optics Works

With variable focus optics, the laser uses a unique lens that changes the focal distance at incredible speeds. This allows the marker to instantly mark on irregular surfaces. With other methods, there is a delay as the laser must stop marking to move the part to the next focal plane. But, with variable focus, the laser continues to mark without delay between focal points.

What is Vari-Z™?

Telesis Technologies makes a series of proprietary variable lenses for laser marking systems called Vari-Z™. The technology embedded in these lasers has focal range of up to ±78 mm. This gives them an incredible range for marking multiple planes, contoured, and cylindrical parts. And it does this without moving the laser and very minimal delay in the lens adjustment. In fact, the cycle time while using Vari-Z will be very near to what the cycle time would be if marking a flat plane. And because there is no need to move the laser or part, it eliminates worn pallets and fixtures on the production line.

AutoFocus for your laser

When paired with an AutoFocus system, the Vari-Z™ laser can automatically adjust the laser to find the focal point of a part. This allows multiple-sized parts to be marked without moving the laser. With AutoFocus, each time the laser receives a command to print, a sensor measures the distance to the part. Then, the Vari-Z™ system adjusts the lens for focus. With Telesis Vari-Z™ and AutoFocus, you can be assured of a perfectly focused mark each and every time!


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