Understanding the Centre Lathe: components & functions

• Centre Lathe is a machine that removes metal from a cylindrical metal piece to achieve the desired size or shape.

Parts of the Centre Lathe

• The headstock contains the gears and mechanisms to drive the spindle
• Chuck: holds the workpiece
• Guard: provides safety by protecting the operator from flying chips and coolant
• Coolant supply: cools and lubricates the cutting tool and workpiece
• Light: illuminates the work area
• Tool post: secures the cutting tool
• Top slide: provides fine adjustments to the cutting tool position
• Gear levers: control the spindle speed
• Tailstock: supports the workpiece at the opposite end of the headstock
• Leadscrew: used for threading operations
• Motor lever: starts and stops the motor
• Cross slide: moves the cutting tool perpendicular to the lathe axis
• Saddle handle: controls the longitudinal movement of the saddle
• Feedshaft: provides automated longitudinal feed to the cutting tool
• Emergency stop: immediately stops the lathe
• Lathe bed: is the base of the lathe and provides a rigid support for all the components.

Equipment used

• Three-jaw chucks allow for quick and accurate centering because the jaws move simultaneously.
• Four-jaw chucks allow each jaw to be adjusted independently, making them suitable for holding irregularly shaped workpieces.
• Chuck key: is used to tighten or loosen the chuck jaws.
• Live centre: has a bearing rotation, which provides better rotation, making it suitable for supporting workpieces in between centres
• Dead centre: is a metal shaft with a point.
• Centre drill: creates holes for the live or dead centres.

Metal Lathe Tools

• Lathe cutting tools: made from high-speed steel.
• Shank: is the part of the tool that is fixed into the tool post.
• The cutting tool should be centred to the same height as the tip of the tailstock centre to ensure good finish.

Operations on the Metal Lathe

• Facing off: A piece of steel is placed in the chuck, and a lathe cutting tool levels the end.
• Parallel turning: A layer of material is removed from the rod's surface, with a Vernier calliper used to measure.
• Taper turning: A small amount of metal is removed to form the taper.
• Drilling: The tailstock supports the drilling with a drill chuck attachment.
• Knurling: A knurling tool presses a pattern onto a round section, typically for a grip.

Health and Safety

• Always receive safety instruction before operating the centre lathe.
• The guard must be in position during operation.
• The material must be securely placed in the chuck.
• The metal should not extend too far from the chuck as this increases the risk of an accident.
• Always wear safety goggles
• Hands and fingers must be kept at a safe distance from rotating parts.
• Lathes should have emergency stop switches.
• The machine should be set to operate at recommended speeds and feeds.
• Apply appropriate coolants to the material being turned.