Tool Break System MaintenanceFast Tool Break Monitoring (SBBK)The "Fast tool break monitoring" option allows tools to be checked for breakage during a tool change. Only complete broken tools are detected, not breaks in individual cutting tips. Length changes of 2mm and more (tolerance), which may result in a tool break, are detected. SBBK is activated for each tool in the user-specific tool datum $TC_TPC3 by setting bit 3 (decimal value = 8) (See image SBBK Active) . As a result, the tool is checked for breakage after each tool change. The Fast tool break monitoring (SBBK) scanner, is located above the provisioning place (tool change area) and can be accessed by removing the access panel above the tool change door. 
Measuring is carried out "mechanically" by scanning the tool with a measuring needle. During the measuring process, the tool is located in the provisioning place. The measuring needle moves at maximum speed out from the idle position towards the measuring angle (see diagram). The measuring angle to be approached is derived from the determined reference value of the tool (See Image SBBK Reference Value), to which a tolerance value is applied. Before the tool is scanned, the speed is reduced. To prevent a waiting period occurring during measuring, the traverse movement can be triggered at the next machining position as early as the tool change. Drilling tools with the following geometric data can be reliably checked. - Tool length: 70 mm to 600 mm - diameter: 1 mm to 5 mm - Point angle: up to 118° 
Fast tool break monitoring is intended particularly for time-critical NC machining, which involves predominantly those tools listed below. The following tool types can be monitoring particularly effectively with the "Fast tool break monitoring" option. - Drilling tools diameter up to 5 mm, e.g - HSS Drills - Coated Drills - Solid carbide drills - Step drills - Tap up to M6
 Calibration of the SBBK Broken Tool Detect is no longer required, as only a reference measurement is carried out. When a new tool is loaded into the machine, or when an existing tool has no value in the OEM Tool SBBK Ref field, an initial reference value scan is performed of the tool while in the provisioning place. The reference values must be recalculated if the installation position of the SBBK device is changed, the needle is exchanged or the motor is replaced. To avoid having to delete all values manually, the control system contains an NC cycle to reset all values. This cycle is called MS_SBBKINI and must be run from the MDA mode. Upon running of this NC cycle, all reference values are deleted and recalculated on the next tool provisioning. The SBBK unit can also activated (1) or de-activated (0) in General MD 14512[60], bit 0. In addition, the tolerance is found in General MD 14510[160] (5=0.5°), and a user specific tolerance can be programmed within the NC cutting program using the variable GV_SBBK_TOL=1 (tolerance in 1/1°). |