Laser system for tool setting and tool breakage control

The LaserControl NT is a third generation from Blum-Novotest. A laser system installed in a machine tool creates a high precision light barrier. When the beam is interrupted by a tool, a trigger signal is produced allowing the control to read measurement values from axis positions. For reliable tool measurement, a tool is positioned in the laser beam and then measured “out of the beam”. The problem of the beam passing the tool between two cutting edges already in the direction of the receiver causing a measurement error is avoided by a microprocessor that is integrated into the laser system. This microprocessor generates the trigger signal for the machine control only when the effective radius -- the longest cutting edge -- completely leaves the beam when there was no interruption of the beam for the entire revolution of the tool. “Out of the beam” measurement eliminates the interference caused by coolant and allows the user to realise a reliable and essentially faster tool setting. Another advantage of the NT technology is the variable adaptation of the length of the laser system trigger signals. Until now, the trigger signal had to be adjusted to a defined period (for example, 5 ms); the single cutting edge control (control of every individual cutting edge of a multiple cutting tool concerning breakout or wear) could only be carried out at a specific speed. This is a disadvantage for HSC spindles as the tool length can vary considerably due to thermal growth and lower pre-tension of the bearings.