3-Axis Laser Marking

In conjunction with Cambridge Technology (CTI), Synrad's Applications Lab has set up a 400 W Synrad laser with a Pro Series 2 3-axis marking head, giving us the ability to demonstrate and qualify large field and/or 3D marking applications. A 3-axis marker, instead of a standard 2-axis marking head, may be necessary for a variety of reasons. Much larger mark fields are attainable and can measure up to several feet square. In addition, smaller spot sizes are attainable in comparable field sizes to those provided by 2-axis markers. Also the optical design of 3-axis markers allows better laser power handling capabilities and as a result, higher power lasers can be used. Finally, a 3-axis marker allows you to dynamically adjust the focus point on the fly allowing you to mark steps, slopes, contours, or even curved surfaces without moving the part or marker.

For simple 2D marking on a plane, the choice for cost effectiveness between a 2-axis marker and a 3-axis marker is dictated by many variables. For applications which need the flexibility of large dynamic mark field sizes combined with the smallest possible spot size, the 3-axis marker is the clear winner in speed and cost. However, for small fixed field sizes which do not need optimal spot sizes, a 2-axis marker can be faster and more cost effective.

For this application demonstration, an anodized aluminum alignment fixture was marked with text labels on both its upper and lower surfaces, which were separated by a distance of 50.8 mm (2 inches). To mark both surfaces in a single mark session, we created two filled 5 mm high TrueType® text objects using CTI's ScanMaster Designer software. Using 100 W of power, we marked the filled text objects in both Z-axis planes in a cycle time of 3.84 seconds.

For information on Cambridge Technology 3-Axis Heads, please contact Mike Fitts at mfitts@cambridgetechnology.com

Laser Marking Beverage Glass

Laser marking steeply curved surfaces is difficult even for 3-axis heads. Line of sight issues eventually become a problem due to the geometric constraints of the surface being marked. This means that marking the circumference or even the side wall of a cylindrical object is impossible with stationary markers. However with WinMark Pro’s radial bitmap marking feature and a simple stepper motor, steeply curved surfaces or an entire circumference can be easily marked, using a standard FH Flyer marking head. This setup means the beam is always perpendicular to the part surface and the mark is always centered under the marking head to maintain perfect focus.

To demonstrate this feature, we marked a bitmap logo on a beverage glass by wrapping around the curvature of the glass while always being perfectly in focus. A Synrad 60 W laser was used for these tests along with a Flyer marking head equipped with a 125 mm HP (High Power) focal length lens and controlled by Synrad’s WinMark Pro laser marking software. This setup produced a focused spot size of 180 mm (0.007”) on the glass surface. The glass was rotated by a simple stepper motor controlled by a single input and a single output connected to the Flyer head.

The mark file consisted of a 55.4 mm x 76.2 mm (2.18” x 3”) imported bitmap logo. For this bitmap object, the Power was set to a duty cycle equivalent to 60 W and the Velocity was set to 1905 millimeters per second (75 in/sec). The Resolution was set to 300 scan lines per inch to match the gearing of the stepper motor (also 300 steps per inch) to prevent distortion of the graphic. The Radial Marking Property was set to Yes with the Part Moving Input and Step Command Output properties set according to the I/O scheme described in WinMark Pro Application Note #7 (available here on the WinMark Pro website).

The resulting mark was completed in 19.55 seconds. Each bitmap scan line is marked in a stationary position directly underneath the marking head before the glass is rotated slightly for the next scan. However, as seen in the video, the step and rotate process is so quick that the glass appears to rotating in a continuous motion during the marking process.

Lasers in Manufacturing Event - Be our Guest!

To attend LME 2011 for FREE as Synrad's guest, click here and enter code: SYNRAD. You must register in advance to receive free event admission, so please act now.

The Lasers For Manufacturing Event (LME) is being held September 27-28, 2011, in Schaumburg, Illinois at the Renaissance Schaumburg Convention Center Hotel. This premier event will focus solely on lasers in manufacturing. See the latest in laser technology, attend educational courses, network with the industry's elite, and find solutions to current and future manufacturing needs.

During the show, stop by Synrad's booth, #2046 to see laser processing video presentations and samples of laser processed materials.

Coming Soon - Firestar i401

The new Firestar i401 laser provides 400 watts of near-perfect beam quality from a single tube. Built around a hybrid waveguide/unstable resonator design, the i401 is driven by four field-replaceable integrated RF modules resulting in a rise time of less than 100 μs, which is 33% faster than existing f-Series lasers. Internal beam conditioning before the output aperture first conditions, aligns, and then rotates the linear beam polarization 45° as an aid in applications where a circular polarizer is used.