Design and analysis of Power hack Saw attachment to a Center Lathe
Center Lathe
description
Transcript of Center Lathe
• The Centre Lathe is used to manufacture cylindrical shapes from a range of materials including; steels and plastics.
• Components that assemble to make an car engine work have been made using lathes.
• The Lathe may be operated by people (manual lathes) or computer controlled lathes (CNC machines) that have been programmed to carry out a particular task.
A basic manual centre lathe
• The lathe is controlled by a person turning handles on the top slide and cross slide in order to make a part.
Lathe Parts
• Lathe bed Made from rigid cast Iron Accurately machined
slideways Slideways guide carriage
& tailstock Headstock on upper end
of the lathe bed
Lathe parts
• Headstock Holds lathe spindle
and gears Chuck is fitted to
spindle Spindle is hollow for
long bars
Lathe parts
• Tailstock Can be moved along
slideways Can be clamped
in any location Inside tapered
to hold drill chuck
Lathe parts
• Carriage Moves along bed
between tailstock and headstock
Saddle – across the lathe
Apron – hangs down in front
Lathe parts
• Top Slide (Compound slide)
Fitted to top of Cross slide Carries toolpost and cutting
tool Can rotate to any angle Is used to turn tapers
Lathe parts
• Feed shaft Used to move the
Carriage automatically
• Lead screw Used when screw
cutting on the lathe
Lathe Parts
• Three Jaw Chuck Self centring Holds round and
hexagonal work 3 jaws are connected Jaws are stamped 1,2 & 3
and fitted in order Chuck key used to open
Lathe parts
• Toolpost Fitted on top slide and
carries the cutting tool or the cutting tool holder
Can adjust the height on some types
Can carry 4 different tool holders
Lathe parts
• Tool holders Used for holding
cutting tool bits Available in Right
hand, left hand and straight
• Cutting Tools Can be High Speed
Steel held in tool holders
Can be also Ceramic (Tungsten carbide) bits held directly in toolpost
Cutting Tool Angle
• Clearance angle Ensures only the
cutting edge of the tool touches the work
Too much clearance causes chatter
Cutting tool angle• Rake Angle Allows the chip being cut
to flow out Changing the rake
changes the power used in cutting and the heat generated
Large rake = soft ductile materials
Small rake = hard brittle materials
Cutting tools
• We can put different shapes on the High speed tool bits to cut different shapes on the workpiece
Parallel Turning• The tool moved parallel to
the work and cylindrical shapes are formed
• Also known as sliding
Parallel Turning
• The student can Parallel turn the work on the lathe manually or use the automatic traverse option
Facing off
• The tool is moved at right angles to the work using the cross slide
• Flat surfaces are produced
Knurling
• A knurling tool is used to press a pattern onto a round section.
• The pattern is normally used as a grip for a handle.
• This provide a grip for the round parte.g. Screwdriver
Parting off• If the student wants to cut
off the part they have turned, they can use the hacksaw and a vice or use the parting off tool on the lathe.
Setting the tool height
• The cutting tool on the lathe must be set to the exact centre of the work-piece
• We use the centre of the tailstock to guide us to the correct height
Screw-cutting on the lathe
• Lathes are also used to cut threads in round bars
• These threads take up different profiles e.g iso (60°) ACME etc.
• These threads can be seen on bench vices, lathes etc.
• In Industry it is not efficient or profitable to make everyday products by hand.
• On a CNC machine it is possible to make hundreds of the same item in a day.
• First a design is drawn using design software, then it is processed by the computer and made using the CNC machine.
• In industry, CNC machines can be extremely large.