Work holding on lathe machine
- 1. Method Of holding work
- 2. Method of Holding Work • There are several method of holding work piece on the lathe machine. This presentation looks on a few of them.
- 3. Chucks
- 5. Chucks • Used extensively for holding work for machining operations – Work large or unusual shape • Most commonly used lathe chucks – Three-jaw universal – Four-jaw independent – Collet chuck
- 6. Three-jaw Universal Chuck • Holds round and hexagonal work • Grasps work quickly and accurate • Three jaws move simultaneously when adjusted by chuck Key
- 7. Four-Jaw Independent Chuck • Used to hold round, square, hexagonal, and irregularly shaped workpieces • Has four jaws – Each can be adjusted independently by chuck Key • Jaws can be reversed to hold work by inside diameter
- 8. Collet Chuck • Collet chuck is used to hold smallCollet chuck is used to hold small workpieces.workpieces. • Used for high-precision work • Spring collets available to hold round, square, or hexagon-shaped workpieces • Each collet has range of only few thousandths of an inch over or under size stamped on collet
- 10. | Collet Chuck Special adapter fitted into taper of headstock spindle, and hollow draw bar having internal thread inserted in opposite end of headstock spindle. It draws collet into tapered adapter causing collet to tighten on workpiece.
- 12. Work Held Between Centre
- 13. Work Held Between Centres
- 14. Face plate • A faceplate is the basic workholding accessory for a lathe. It is a circular metal plate which fixes to the end of the lathe spindle. The workpiece is then clamped to the faceplate, typically using t-nuts in slots in the faceplate, or less commonly threaded holes in the faceplate itself.
- 15. Faceplate • Used to hold work too large or shaped so it cannot be held in chuck or between centers • Usually equipped with several slots to permit use of bolts to secure work
- 16. Mandrel • Holds internally machined workpiece between centers so further machining operations are concentric with bore • Several types, but most common – Plain mandrel – Expanding mandrel – Gang mandrel – Stub mandrel
- 17. Plain Mandrel
- 19. Gang Mandrel
- 20. Summary • The method use is highly based on the: • Shape of metal • Length of metal • Type of operation to perform • Condition of the workpiece