Combination Chuck Enables Off-Machine Presetting

The Gripfast Combination Power Chuck from Pratt Burnerd International, a division of 600 UK, provides lathes with a chuck, collet chuck and mandrel chuck in a single unit, available in sizes ranging from 165 to 800 mm. According to the company, the chuck's counterbalance feature negates centrifugal force effects, ensuring constant gripping force and 90-percent jaw force at maximum operational speed of 6,000 rpm. A duplicate set of master jaws and an off-machine jaw-setting fixture enables jaw presetting off the machine for change-overs as fast as 30 sec. The master jaws accept a range of standard or special collet pads, enabling the unit to be quickly converted to a collet chuck. The company's Setrite feature promotes adjustment accuracy of the jaws, collet pads and mandrel. The chuck can be supplied with optional large through-bore capacities to fit different models of CNC production lathes in combination with existing chuck assemblies.