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BK MIKRO 4 is a broken tool detection system designed for tool detection as well as for object and free space monitoring applications.

The complete BK MIKRO 4 system includes:

  • Control unit - BK4110
  • Sensor (scanner) - BK4SC (TK4K.xx)
  • Connection cable - BK4C5
  • Mounting Bracket - BKMB
BK Mikro 4  System

BK Mikro 4 typical uses:

  • Monitoring of a scanning position or tool whose precise location has been previously entered by "teach-in" or "learn". This position is then checked after each cycle to verify the tool or position is still present within a +/- 10 degree window.
  • Monitoring a scanning range or position selectable via two adjusting switches. This is used to carry out tool checks on tools whose diameter varies more than the +/- 10 degree checking window set with a Teach/Learn cycle.
  • Monitoring an area for free space using the two adjustable switches to set the scanning range.
    • A typical free space monitoring application would be to verify a part has been ejected from the sub-spindle of a lathe before the main spindle tries to load another part into it.

Further features enabling customized system configuration include:

  • Fault and OK outputs are Relay Contacts which can be selected to either normally open or normally closed.
  • Selection of clockwise or counter-clockwise travel direction for the scanning wand.
  • Two settings of controlled acceleration and deceleration allowing for the checking of small diameter tooling.
  • Internal diagnostics which detect cable breaks.
BK Mikro 4

Principle of Operation:

BK Mikro 4  Operating Principle
Once a position is set either with a Teach/Learn or via the adjusting switches the system is ready for operation. Simply apply a 24vdc signal to the "Start" terminal to initiate the scanning cycle (this can be done via the CNC, PLC or with a relay). The wand will rotate to the selected position and verify that the tool or object is present. If everything is alright the unit will output an "OK" signal to allow the machine cycle to continue. If the tool is broken the wand will travel past the stored position and the controller will output a "KO" signal to let the machine know there is a problem and shut down automatically. The wand must also travel to a minimum position. This is important because if the wand is blocked with chips or an obstacle the unit will output a fault alerting the operator that there is a problem.

Competitor systems only fault if the wand travels past the checking position completing an internal circuit (limit switch). This will allow a broken tool to go undetected because the wand is stuck and the unit thinks everything is ok allowing for scrap parts or machine crashes.

Control Unit:

BK Mikro 4  Control Unit

Controller Technical Data:

  • Housing: Insulated Material Housing, Protection Class
  • Protection Type: IP 20
  • Dimensions (W x H x D): 45mm x 75mm x 107.5mm
  • Case Mountings: DIN Rail, 35mm, to DIN EN 50022
  • Power Supply Voltage: 24 VDC or 120 VAC
  • Power Consumption: 6 VA max
  • Control Voltage: 24 VDC (internal/external)
  • Inputs: Input Current: 5mA approx.
  • Pulse Duration: 6ms min.


BK Mikro 4  Scanner

Scanner Technical Data:

  • Housing: Anodized Aluminum
  • Protection Type: IP 67
  • Wand Length: 165mm (standard)
  • Scanning Angle: 0° to 270°
  • Control Unit Connection: Connector, M12x1, 3 pins
  • Temperature Range: 0°C to +80°C
  • Sensing Cycles: > 10 million with normal deceleration

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