This Longworth chuck is attached to the lathe via your scroll chuck grabbing onto the 60mm solid backing plate. This allows compatibility to most chucks, no need to worry about thread size and easy switching. CNC machining of the chuck ensures the disc plates rotate smoothly for adjusting the clamping diameter of the chuck. The compressible silicon rubber buttons are non-marring and won’t leave any scuff marks on your lathe turnings. A quick twist of the wing nuts locks the plates together and compresses the rubber buttons to grip your work piece. The chuck can grip your project from the outside (outside compression mode) or the inside (inside expansion mode). Once the gripper buttons are firmly up against your project, secure them by tightening the wing nuts. Requires a scroll chuck. Detailed Instructions available here. Longworth Chuck Size Outside Compression-Min. Outside Compression Max. Inside Expansion Min. Inside Expansion Max. 250mm (10") 75mm (3") 200mm (8") 145mm (5-3/4") 240mm (9-1/2") 300mm (12") 75mm (3") 250mm (10") 145mm (5-3/4") 290mm (11-1/2") 350mm (14") 75mm (3") 300mm (12") 145mm (5-3/4") 340mm (13-1/2") 400mm (16") 75mm (3") 350mm (14") 145mm (5-3/4") 390mm (15-1/2")
