Scott Schmidt, Product Manager for Aerotech’s Laser Processing and Micromachining Group, recently interviewed Scott Tompkins, Senior Electrical Engineer with Innovative Laser Technologies, about the pros and cons of implementing high-speed scanners in precision laser applications. Scott Tompkins has over 20 years of experience in laser machine design and integration, and his answers provided some interesting insight from someone on the front lines of implementing this important technology. Let an expert in the field help you avoid the pitfalls and speed the commissioning of your next system.
Q. What is the easiest and most difficult element in setting up and integrating industrial scanners?
A. Configuration and Calibration are not easy especially when you are mixing software and hardware vendors.
Q. What high-speed galvo features do you wish were available but currently are not?
A. There is very little diagnostic info when using xy2-100 interface. We have found that vision through the galvo lens produces distorted images and would really like to improve the image so that we can do more detailed vision processing.
Q. What are some typical uses and applications for galvos in precision laser manufacturing?
A. Micromachining, welding.
Q. What are some challenges that might not be obvious when setting up and using scanners in high precision laser applications?
A. Laser pointing stability can create problems. We have developed tools to correct for it.
Q. Do you have laser preferences in high-speed scanning systems versus those systems with fixed-beam delivery? For instance, fiber delivery of the beam, mode-locked (or not) lasers, etc.?
A. No, we try to stay laser neutral.
Q. Do you typically use “standard” modelled correction tables to improve galvo accuracy, or must each device be individually calibrated using, for instance, mark-and-measure processes? What final point-to-point accuracy is required by the galvo?
A. We use mark and measure. As a general rule, accuracy is directly proportional to the final spot size.
Q. Do you have servo stage preferences in hybrid (servo + scanner) systems? For instance, split bridge, gantry, or simple stacked XY/Z configurations?
A. We usually end up with stacked XY, with the galvo head on Z.
Q. What system or motion controller features (if any) must typically be given up to accommodate galvos within an application solution?
A. The working surface or part must be very flat within the galvo field.
Q. Does availability of specific scanner features (for instance, aperture size, mirror coating wavelength, or power/pulse energy handling capability) influence the laser choice at all?
A. We have not found that to be the case.
Q. If you could choose one feature that would be ideal for your galvo applications, what would that feature be and what problem would it solve?
A. We would do a lot more vision processing through the galvo if the images were less distorted and clearer.