Week 3, 4, 5 and 6
Edge Finder
Different models are manufactured. Three basic types are the edge finder, wiggler or center finder. Used to accurately determine the edge of a part or center of a pre-machined hole
Split-nut Lever
Engaged the carriage directly to the lead screw, is used only for threading, will only engage when the feed is set in the neutral position
Vertical Milling Operations
Face milling, End milling, Keyway cutting, dovetail cutting, T-slot and circular slot cutting, Gear cutting, drilling, boring, jig boring
Spindle
Is the shaft which is used to hold and drive the cutting tools of the milling machine Mounted on the bearings and supported by the column Spindle is driver by the electric motor The draw bolt and jaunt is used to secure the holder and arbor in the spindle
Table
It is a rectangular casting which is present on the top of the saddle Used to hold the work or work holding devices The table can be operated by hand or by power
Plain Vise
Jaws parallel or 90 degree to axis of spindle
Milling Clamp Kit
Kit provides a selection of studs, nuts, tee nuts, clamps and stepped blocks Can help securely hold down all jobs, vices and fixtures to bed of milling machine
Knurling Tool
Kurling tool with one set of rolls in self-catering head.
Solid Dead Center
Support during cutting Most common have solid morse taper shank 60 degree enters, steel with carbide tips Care must be taken to adjust and they must be lubricated occasionally
Carriage / Apron Handwheel
The carriage hand wheel is used to manually position and/or hand feed the carriage in the longitudinal or z-axis
X and Y
The digital read out on school mills only have these axis
Solid Collet
These are a lot more rigid than spring collets. Pulled into spindle by draw-bar. Driven by setscrew that bear against flats of cutter shank.
Tool Holder (tool post)
This is where cutting tool is mounted Usually three different kinds: Single, four sided square and quick change
Quill Fine Feed Handwheel
This offer operator controlled slow manual feed.
3 Common Lathes
Toolroom, heavy-duty, Gap-Bed
Feed Rod
A mechanism used for precise linear movement of the lathe carriage.
Keyway
A precise machined slot or pocket. Usually milled with an end mill.
Lead Screw
A screw for operating the lathe carriage when cutting threads
Center Drilling
A small twist drill used to make centers in a work piece to be turned between centers Used as a center drill guide on centreline of a part before drilling, because of length and tip angle twist drills will tend to deviate if a center drill is not used first Center drills can also be sued to spot holes on the mill or drill press. This is to prevent twist drill from wandering
Quick Change tool post
Allows the use of multiple tools, allowing tools to stay centre even if the holder is removed.
End Milling
Also known as face milling. Common form of removing material to create a variety of features in work piece
Knurling
Alter either the shape or finish of round work piece Normally performed on work mounted in chuck Can also be done on work mounted between lathe centers Process of impressing a diamond-shaped or straight-line patter into the surface of the work piece. Improves its appearance, provides better gripping surface and increases work piece diameter when press fit required.
Head
Attached to end of ram Made to swivel in one plane Universal type machines allow swivel in 2 planes
Knee
A casting that supports the saddle and table All gearing mechanism is enclosed within the ______ The ______ is supported and adjusted by a vertical positioning screw The elevating screw is used to adjust the knee up and down by raising or lowering the lever either with the help of hand or power feed
Drilling
Calculated RPM is a good starting point, but you may have to reduce speed Must take into consideration tooling, machine, how work piece is being held etc.
Four Sided square tool post
Can hold hour different cutting tools
Swivel Base Vise
Can swivel through 360 degree in horizontal plane
Universal Visa
Can swivel through 360 degrees in horizontal place and tilted from 0 to 90 in vertical plane
Tool Set Too Low
Causes high cutting forces and ship will curl tightly Insert fracture may happen Poor surface finish Part being machined may climb over tool and be torn from machine
Headstock
Clamped on left-hand of bed Spindle hs hollow cylindrical shaft supported by bearings, provides drive through gears to work-holding devices; has a live centre, faceplate or chuck fitted to spindle nose to hold and drive work Driven by stepped pulley or transmission gears Feed reverse lever reverses rotation of feed rod and lead screw
Milling Machine
Combines vertical spindle of drill press with longitudinal and traverse movements of ______ _______. Used to produce one or more machined surfaces accurately on work piece. Work piece held on work table or holding device and brought into contact with cutter. Spindle speed changed by variable-speed pulley/crank or by belt changes and reduction gear. Milling process may be vertical, horizontal, angular, or helical. Can machine in one, two, or three planes. Used for milling, drilling, boring and reaming.
Quick Change Gearbox
Contains number of different size gears Provides feed rod and lead-screw with various speeds for turning and thread cutting operations NEVER change speed when lathe is running
Feed Lever
Controls RPM and travel speed of carriage Distance carriage will travel in one revolution of spindle Controlled by change gears in quick-change gearbox chart mounted on front of quick-change gearbox indicates carious feeds
Tool Set too High
Cutting point is above center line of part being machined This will shorten the life of the insert or carbide tooling Will also case poor surface finish When facing may cause insert to fracture and leave nipple on material being machined
Lathe Size and Capacity
Designated by largest work diameter that can be swung over lathe ways and generally the maximum distance between centers. Manufactured in wide range of sizes. Typical lathe: 13 in. swing 6 ft long bed 36 in. between centers. A-Swing B- Distance between Centers C-Length of Bed D-Radius
Tapping Procedure
Face part to make sure it is square and flat to the work piece Center drill face (3/4 of the taper on center drill) Drill proper tap drill size to determined depth Chamfer hole to remove burrs Place tap in drill chuck and tighten Place machine gears in neutral Push tailstock towards chuck till tap is in piece While applying pressure on tailstock manually spin chuck Observe tap slowly cutting metal as to rotate part and keep turning chuck back and forth until approximately 0.250" deep Stop applying pressure to tailstock and rotate chuck opposite direction to remove tap Finish tapping part in vice at the bench with tap handle
Apron
Fastened to saddle Houses hears and mechanism required to move carriage or cross-slide automatically Locking-off level inside apron prevents engaging split-nut lever and automatic feed level at the same time
Compound Rest
Fitted on top of cross-slide used to support cutting tool can be adjusted independently of the carriage or cross slide swivelled to any angle for taper-tuning (total of 90 degrees) Has graduated collar that ensure accurate cutting-tool settings (0.001 in) Used for tuning small tapers, precision feeding (manually)
Spring loaded Slip Clutches
Found only on feed rods When feed mechanism is overloaded the shear pin will break or this will slip and cause feed to stop
T-slot
Grooves in worktables, fixture and holding devices. Cutting is side cutting and mounted to then of a shank
Quill Feed Hand Lever
Handle used to raise and lower quill manually
Carbide Toolholder
Has square hole parallel to base of tool holder to accommodate carbide-tipped tool bits designated by letter C
Bed
Heavy rugged casting, made to support working parts of lathe, top sections are machined ways which guide and align major parts of lathe.
Tool Holder for indexable Carbide Inserts
Held in holder by cam action or clamps Types: Conventional, turret-type and heavy duty tool posts
Drill Chucks
Hold drills, reamers, center drills, edge finder etc. Can be both keyed and keyless. Never put an end mill in drill chuck.
Spring Collets
Hold end mills, cutting tools and accessories in machine spindle. Pulled into spindle by draw-bar that closes on cutter shank. Driven by means of friction between collet and cutter.
Three-jaw Universal Chuck
Holds round and hexagonal work Grasps work quickly and accurate within a few thousandths/inch All jaws move simultaneously when adjusted by chuck wrench causes by scroll plate into which all jaws fit Two sets of jaw: outside chucking and inside chucking
Gravity Fed Vertical Band Saw
Horizontal band saw on a vertical frame. An all-purpose band saw, it handles all metals, plastics, and wood in a wide variety of cuts. Can be used as a cut off saw, rip saw and notch blocks. The blade and vertical column travels on an inclined track that feeds into the cut in a straight path. Gravity enables the blade to find its most efficient feed rate. Counterweight control provides adjustment for optimum cutting pressure and long blade life. The work piece remains stationary and your hands need not be in the cutting area during cut-off, an important safety feature.
Ram
Horizontal beam precent at the top face of the column. It may be single casting which slides on the dovetail ways present on the top face of the column Used to move spindle closer or further away from column
Tool Set Center Line
Longer tool insert life Optimum chip breaking Very good surface finishing Little to no nipple on machined part when facing
Shear Pins
Made of brass Found on feed rod, lead screw and end gear train When the feed mechanism is overloaded this will break and cause the feed to stop
Base
Made ribbed cast iron may contain coolant reservoir
Knurling Procedure
Mount work and mark required length to be knurled. Set lathe to turn at one-quarter speed required for turning. Set carriage feed to .015 to .030 in. Set center of floating head of knurling tool even with dead-centre point. Set knurling tool at right angels to work piece and tighten it securely. Start machine and lightly touch rolls against work to check tracking. Move knurling tool to end of work to only half the roll face bears against work. Start lathe and then force knurling tool into work until diamond pattern come to point. Once pattern correct, engage automatic carriage feed and apply cutting fluid to knurling rolls. Knurl to proper length and depth. If knurling pattern not to point after length has been knurled, reverse lathe feed and take another pass.
Cross-slide
Mounted on the top of the saddle had a feed screw that travels at right angled to the main spindle axis Provides manual or automatic cross movement for cutting tool
Motor
Mounted on top of head Provides drive to spindle through V-belts or gears
Engine Lathe
Not a production Lathe, found in school shops, poolrooms and jobbing shops Basic to all lathes Accurate and versatile machine Operations that can be preformed on lathe are turning, tapering, herding, facing, drilling, boring and polishing Lathe is considered the forerunner of all machine tools First application was the potters wheel
Column
Often cast with base Machined faces provide ways for vertical movement of knee Upper part is machined to receive turret where ram is mounted
Single Tool Post
Only holds one cutting tool at a time
Facing
Operation used to remove metal form the end of a work piece Work piece is rotated against a single point tool Is used to machine work piece to specified length Mostly done on cylindrical parts, can also be done on non-cylindrical parts using different holding accessories for example a four jaw chuck
Shear Pins and Slip Clutches
Prevents damage to the feed mechanism from overload or sudden torque
Revolving Tailstock Center
Replaced solid dead centers for most machining operations Contains anti friction bearings which allow center to revolve with workpiece No lubrication is required between center and work Types: revolving dead center, long point center and changeable point center Parts to be turned with renters must be center drilled to provide bearing surface
Endmills
Type of milling cutter. Different from twist drilll because of its application and geometry. Can generally cut in all directions.
Tailstock
Upper and lower castings Adjusted for taper or parallel turning by two screws set in base (offsetting screw) Clamp lever locks tailstock in any position along bed of lathe. Spindle has internal taper to receive dead center Standard tapered-shank tools can be held in spindle Spindle-clamp used to hold spindle in fixed position Hand Wheel moves spindle in or out of casting, used to provide hand feed for drilling and reaming operations
Chuck
Used extensively for holding work for machining operations Work large or unusual shape Most commonly used lathe chucks
Saddle Traverse Crank
Used for moving table along the Y axis
Table Traverse Crank Handle
Used for moving the table from left to right on the X axis
Boring Head
Used to enlarge an existing hole. Boring head uses single-point cutting tool. Capable of achieving great accuracy.
Face Mill
Used to mill flat surfaces that are at right angles to axis or the rotating cutter. Come in multiple diameters and amount of inserts.
Carriage
Used to move cutting tool along lathe bed Consists of the Saddle, cross-slide and apron
Vertical Knee Traverse Crank
Used to raise or lower the saddle in the Z axis
Steady (Compound) rest
Used to support long work held in chuck or between lathe centres located on and aligned by ways of the lathe Positioned at any point along lathe bed Three jaws tipped with plastic, bronze or rollers may be adjusted to support any work diameter with ____ ______ capacity