With its Active Speed Control, Luton-based Trumpf Ltd (www.trumpf.com) says it has reached a major milestone on the road to autonomous machining.

The system looks straight through the nozzle at the cutting zone, monitoring it in real time and autonomously controlling the feed rate of solid-state laser machines — and responding immediately to any changes in the material being processed for gains in productivity.

It monitors numerous process parameters, including the position of the laser beam in relation to the centre of the nozzle during the entire cutting process, informing the operator of any deviations and helping avoid scrap.

Additional functions for automated laser cutting can easily be added to the system in the future, thanks to the software update feature.

Trumpf says the kerf reveals all sorts of information about part quality and process stability, and the easier it is for the molten material to escape from the kerf, the smoother the cutting process.

Active Speed Control monitors this flow of molten material in mild-steel and stainless-steel plates that are more than 4mm thick.

The sensor system observes the radiation that is emitted as the material melts to determine whether the molten material is emerging as planned, identifies the fastest-possible feed rate and makes any necessary
adjustments (many hundreds of times a second); it maintains the optimum feed rate even in cases where the thickness of the material varies within a single sheet, or where the top of the sheet is contaminated with rust or paint.

To allow for variations in material, operators will frequently reduce the machine’s feed rate; and while this can make the process more reliable, it often has a negative impact on the cutting process and the quality of the cut (a lower feed rate can cause heat to accumulate in the material and cause it to melt in an uncontrolled fashion).

The sensor system allows the machine to always work as fast as it can, while maintaining the required levels of process reliability.

In many cases, Active Speed Control even achieves speeds that are significantly higher than the default values specified in the standard cutting data.

Parts that have not been completely cut from the ‘skeleton’ or that feature a lot of slag lead to higher scrap rates and wasted time, especially if the cutting problems occur during a night shift.

However, with automatic feed control, this hardly ever happens.

In the event of a mis-cut, Active Speed Control brings the machine to a halt and the TruTops Monitor software immediately notifies the operator to take action; it also reduces burr and slag formation.