Fail-Safe Collet Block Secures Parts Despite Air Loss

Hardinge’s fail-safe 5C collet block features a spring design to keep parts clamped and maintain concentricity even if air is lost during the machining process. Whether using a single collet block or a sub-plate of multiple blocks, air is required during setup to receive the part. After setup, the spring design holds the workpiece with 1,760 lbs of drawbar force and does not require air during the machining process. The spring-to-close design enables use of pallet shuttles without the need for air or hydraulic lines. The fail-safe design also eliminates the risk of scrapping parts, tparts flying off if loss of air should occur and downtime associated with chip buildup, the company says.

Modular units of the collet blocks can be used vertically, horizontally or in any position for machining or assembly operations. These units can line up on a trunnion plate for fourth-axis, multiple-part machining with a rotary table. Each unit has a 5" square footprint with four mounting holes 4" on-center. Maximum operating pressure is 75 psi. Multiple units will connect to a single pneumatic connection, but can have separate valves for controlled workpiece placement during setup.

The collet blocks feature a through-hole base design that enables coolant and chips to be flushed through, rather than building up. This eliminates the time needed to tear down and clean out the unit.

The company also produces the collets and step chucks for use in the collet blocks. 5C collets will hold round parts ranging to 1 ¹/₁₆", hex parts ranging to ²⁹/₃₂" or square parts ranging to ¾". Step chucks can be used to hold parts ranging to 6" in diameter. Sure-Grip expanding collets will grip the part internally for ID part sizes ranging to 3  ¹/₆₄ ". Dead-Length collets offer exact part length control when machining shoulders and faces, the company says. The part locates against the face of the collet, the back face of a stepped hole or the face of the work stop to ensure no longitudinal end movement. Manual chucks also will thread onto the spindle nose. Much of this spindle tooling can be shared with other CNC lathes.