Press Release Summary:
Step Chucks 16C and 20C are engineered with force control to prevent crushing or distorting thin-wall parts during turning and grinding operations. Units mount directly to spindle and use spring-loaded design as primary closing mechanism. Force-limiting step chuck assembly adjusts grip while eliminating need to manually adjust draw bar force. Since proper grip force is predetermined and applied to process, concentricity is maintained.
Original Press Release:
New Force-Limiting Step Chuck Takes the Headache Out of Thin-Wall Turning
Hardinge has engineered "force control" into 16C and 20C step chucks to prevent crushing or distorting thin-wall parts during turning and grinding operations. The concept incorporates a unique spring-loaded design as the primary closing mechanism. The lathe closer will bottom out before the spring system reaches its solid height. The Hardinge Force-Limiting Step Chuck's features and benefits makes it an ideal replacement for the standard power chuck when turning large or small diameter, delicate or thin-wall parts. The lathe operator will have better control over the cutting process while reducing scrap and maintaining part specifications. Excessive grip force on a delicate or thin-wall part can easily distort or crush a part so that when it is released it will not hold the concentricity. Similarly, you can not hold an out of round shape and maintain that shape when an excessive gripping force is applied. The force-limiting step chuck assembly adjusts the grip while eliminating the nuisance of manually tweaking your draw bar force. The actuation of the system is force independent from the machine draw bar. You can operate at normal pressure, eliminating any loss of closing cycle time associated with a low pressure setting. Hardinge has identified and has engineered solutions for multiple force levels. Each application will be tested for proper use. Not only is there concern for maintaining OD and ID concentricity, but also maintaining a straight, non-distorted face cut for example on a thin-wall aluminum part. Additionally, accurate bore tapers can be achieved. The standard power chuck just doesn't cut it for delicate or thin-wall turning. The Hardinge Force-Limiting Step Chuck offers many advantages over standard and specialized power jaw chucks. Concentricity will be maintained because the proper grip force is predetermined and applied to the process automatically. The standard power chuck grip force is controlled by manually adjusting the draw bar force and tweaking it until you have a satisfactory workpiece, but you're likely to increase setup time and create scrap along the way. The Force-Limiting Step Chuck weighs less than a power chuck and does not require a hoist to mount it. It mounts directly in the Hardinge spindle with minimal overhang from the spindle bearings, therefore transferring spindle accuracy direct to the workpiece. There is less weight on the spindle as compared to a power jaw chuck so that faster rotating speeds can be achieved. The smaller outside diameter provides less inertia and lower mass providing shorter acceleration and deceleration times, at the same time allowing more tool clearance. There is less setup involved because you don't have to bore soft jaws or position hard jaws as you do on a power chuck. Similarly, the Force-Limiting Step Chuck can be used for small diameter parts, such as a connector, to avoid crushing and distortion. Custom shapes can be engineered for holding non-round parts. Hardinge's Force-Limiting Step Chucks are hardened and ground and ordered to size according to each individual application. Threads are heat-treated and the body is spring-tempered to assure accuracy and durability for long life. Currently the force-limiting step chucks are used in Hardinge CNC lathes with a draw bar stroke of 1/2 inch or less, available in 16C and 20C sizes. Applications include gripping thin-wall tubing, pipe, castings, housings, and soft or delicate materials that cannot withstand standard chucking methods. Call Hardinge today for more information on this system. Request brochure T-351 or view Hardinge workholding products online at www.hardingetooling.com. Hardinge Inc., Phone: 800-843-8801.