Most everyone familiar with large-scale industrial laser processing has seen a high-throughput laser CNC machine whirling around, cutting out large sheets and tubes of steel or aluminum with dizzying speed. Those of us involved in laser microprocessing, where part quality depends on micrometers of processing accuracy, wonder if we can achieve such feats of machine throughput and still produce high precision parts. The answer is yes – and the question then becomes “how?” This article explores fundamental considerations in machine design and control that one must be familiar with to get the most throughput possible out of a precision laser microprocessing machine.
The criteria for determining an acceptable part is generally non-negotiable in a manufacturing process. Part tolerances are established by the requirements for a part to function properly or safely. They dictate the allowable error budget of the manufacturing process. The error budget is then “used up” by different error sources stemming from a machine’s design, its controller capabilities and the laser material interactions during processing. The key to achieving maximum throughput while manufacturing high-precision parts is to leave as much of this error budget as possible for dynamic tracking errors. Following sound system and structural design principles and choosing a highly capable motion controller – one that takes the most advantage of the dynamic tracking error budget – will maximize the throughput and therefore the economic justification for a laser micromachining system.
