The term “flying cut” refers to the cutting mode in which the laser is turned on while the head is moving. In normal mode cutting, the machining process has separate paths, so the laser always turns on and off after the movement of the head shafts have stopped.
Piercing On The Fly
To accomplish this kind of cut, the machine and the numeric control must be capable of turning the laser on and off, as well as being precisely positioned at a certain point within a minimum time interval (fractions of a second). To do this, the material thickness must be fine enough to be drilled without any activation time, a process known as “piercing on the fly.”
This cutting mode is useful for certain jobs that involve parts with many interior holes, in which the cutting movements are alternated with short empty movements. In these cases, the machining time is considerably reduced, with a subsequent increase in productivity.
The machining order and process used for the holes must be correct to ensure the best possible performance during fly-cutting mode. The algorithm that calculates the machining order must detect holes in the screens to perform this type of cut.
Depending on the shape of the hole, it has to be partitioned and reformatted to machine the maximum number of elements without changing direction to avoid processing the corners and minimising the speed reduction time for a change in direction. Empty movements are also optimised so they are as short as possible between two cuts and have the smallest possible change of direction.
On a screen with rectangular holes, all the horizontal cuts should be made first, followed by the vertical cuts (or vice versa). Meanwhile, a screen with circular holes is cut one hole at a time, optimising the path of the movements.
Arches And Segments
Apart from these two types of screens, which are the most common, it is also possible to machine another type of hole, composed of arches and/or segments. In this case, the feasibility and optimisation of the machining order with this cutting method depends on the shape and position of the holes.
APMEN Sheet Metalworking, August 2017