Compact measuring device checks pull-in force of micro-tool holder

OTT-JAKOB Spanntechnik, a German manufacturer of tool clamping systems, has launched the Power-Check Micro, a spindle clamping force measuring device for compact HSK E15, E16 and E20 spindle interfaces. It complements the established Power-Check 2 and Power-Check Magazine, which measure pull-in force on larger spindle tapers such as HSK (up to 160), BT, SK and CAT types.

Smaller interfaces are typically used on precise, high-speed machines in sectors including dentistry, jewellery, electronics, medical devices, aerospace, automotive and small toolmaking. In Britain and Ireland, the devices are supplied exclusively by GEWEFA UK. Weighing only 200 g and measuring 48.8 x 43 x 41.5 mm, the Power-Check Micro suits restricted working areas. Powered by two replaceable lithium batteries, it provides up to 1,000 hours of operation without mains supply.

Three interchangeable screw-on adapters allow compatibility with different HSK sizes and clamping systems from all manufacturers. Like its larger counterparts, the unit measures axial force exerted by the drawbar to secure the tool holder in the spindle. Maintaining correct clamping force is essential: even small deviations can accelerate tool wear, cause vibration, lead to poor surface finish or, in extreme cases, result in tool failure.

Based on established OTT-JAKOB technology, the Power-Check Micro delivers precision and reliability in a compact format tailored for small machines. It measures forces up to 5.0 kN and maintains accuracy within ±0.1 kN across the range. The device operates reliably between 10°C and 35°C and up to 50% relative humidity.

A notable feature is the adjustment ring with 0.05 mm graduations, allowing simulation of different tool holder tolerances within a ±0.2 mm range. Unlike conventional systems that reference nominal sizes, this capability enables checks that reflect real-world component dimensions more accurately.

For safety, the device must be inserted manually and should never be presented to a rotating spindle. To use it, the operator switches on the unit, places it into the tool interface by hand and activates the drawbar via the machine control. A flashing green LED confirms active status while the device transmits one data point per second to a receiver. After measurement, the clamping is released and the unit removed.

Wireless 2.4 GHz transmission is supported by OTT-JAKOB receivers, including a USB radio stick for PC data logging and analysis, as well as RS 485-A/D and IO-Link modules for integration with digital manufacturing systems.

The Power-Check Micro is offered as a stand-alone device or as a complete kit with a storage case, receiver, batteries, instructions and software. Annual recalibration and regular inspection are recommended to maintain performance.