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Classification and main parts of centre lathe

Short answer

Lathes are classified as speed, engine, bench, toolroom, capstan/turret, automatic, and special purpose. Main parts: bed (supports all), headstock (spindle and speeds), tailstock (support and drilling), carriage with cross-slide, compound rest, tool post, apron, feed rod and lead screw for turning and threading.

(a) Classify lathes. (b) With a neat sketch, name the main parts of a centre (engine) lathe and state the function of each.

(a) Classification of lathes

  • Speed lathe: simple, 3 or 4 speeds, no feed or carriage; for wood turning, polishing, centring.
  • Centre or engine lathe: general purpose, power feed, lead screw; most common in workshops.
  • Bench lathe: small engine lathe mounted on a bench for light precision work.
  • Tool room lathe: precision engine lathe with a wide speed range and many attachments.
  • Capstan and turret lathes: hexagonal turret holds many tools for repetitive production of small parts.
  • Automatic lathes: loading, feeding and tool change are automatic (cams); for mass production.
  • Special-purpose lathes: wheel lathe, gap-bed lathe, T lathe, CNC lathe.

(b) Main parts of an engine lathe

 headstock           tailstock
 +------+  chuck       __ quill
 |gear  |==[O]--job--<|__|
 +------+   tool post      
 =====[ carriage ]============ bed (ways)
  legs   apron   lead screw & feed rod
  • Bed: heavy cast iron base with precisely machined ways on which carriage and tailstock slide; supports all parts.
  • Headstock: fixed at the left end; houses the spindle, gear box giving different speeds, and carries the chuck or face plate.
  • Tailstock: on the right; supports long jobs with a dead centre and holds a drill or reamer; its body can be set over to turn a taper.
  • Carriage: slides along the bed; consists of saddle, cross slide, compound rest, tool post and apron.
  • Apron: attached to the carriage; holds the gears and clutch for hand and power feed and the half-nut for thread cutting.
  • Feed rod and lead screw: the feed rod gives power feed for turning; the lead screw (Acme thread) moves the carriage for thread cutting.
  • Cross slide and compound rest: cross slide moves the tool at right angles to the axis (facing, depth of cut); the compound rest swivels for taper turning.
  • Tool post: clamps the cutting tool.

✓ Answer checked by Claude Opus 5.5 (high effort)

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