by Eric St. James
Advanced linear motor drives can help fabricators improve processing times
The advent of fiber laser technology has coincided with advances in machine tool axis drives. Traditional DC ad AC servo motor drives coupled to gearboxes or ball screws have long been the industry standard, but linear motors are beginning to replace them.
These new drives use electromagnets to levitate and propel the “carriage.” This technology loses no efficiency to friction of secondary drives and is capable of extraordinary speeds and rates of acceleration.
The high acceleration capability impacts laser cutting performance.
When axis acceleration and deceleration ramps are reduced, the time to arrive at maximum speed is shortened significantly and this directly translates to faster and more efficient processing speeds. One might be tempted to think this difference is negligible but the charts at the far right illustrate clearly the point.
Manufacturing is about efficiency. Reducing processing times is a constant objective and faster drives with higher power lasers do just that. The bottom chart to the right demonstrates that difference in time to produce a given part as rate of acceleration increases.
As the speed and acceleration of linear drive technology increases, there is a need to couple it with more laser power so that the speed is more properly leveraged. More heat is required to vapourize the material at the higher speeds, hence the dramatic difference in capacity with a 6 KW resonator versus the 2 or even 4 kW. Some fiber laser suppliers are now working with 8 and 12 kW resonators for even more dramatic results. With current developments, it will not be long before we are cutting quarter inch plate at the same speed we use to cut 22 gauge plate.
To see the acceleration differences, visit Paramount’s You Tube vidoe. SMT
Eric St. James is director of Paramount Machinery.