Alignment and Setup Procedures

The safe and efficient use of any milling machine is largely dependent on how well the machine and work-holding fixtures are aligned and how rigidly and securely the work is setup. work that is nor held securely may move during the machining process, causing the part to be ruined. there is also the possibility that improperly held work will be pulled out of the fixture or vise, resulting in damage to the machine and possible injury. There are a few types of alignment that is machine alignment, table alignment,head alignment, vise and fixture alignment.

Machine Alignment
Plain milling machines, both vertical and horizontal, do not require table alignment in normal use because the table cannot be swiveled. Overarm-type vertical milling machines that do not have either a swiveling or fully universal head do not require head alignment because the head can move up and down only.

Table Alignment
The table on universal milling machine must be checked for alignment whenever it is being returned to 0˚ position or when a job involving precise angular relationships is to be done. NEVER trust the graduations on the saddle or on any other parts of the machine when really accurate work must be done.

A rigid mounting for the dial indicator is necessary so that flexing and slippage do not alter the readings. The dial indicator must be mounted to the table of the machine because the motion of the table relative to the face of the column is being checked.

Head alignment
The head on vertical milling machines with semi universal or universal heads must be checked before doing jobs requiring accurate alignment between the head and table. It’s important to align the spindle perpendicular the table when drilling, boring, and flycutting operations are performed. The following procedure is suggested for alignment the head of vertical milling machines with semi universal or universal head.

1. Clean the table thoroughly and place a flat and parallel plate on it if one is available.
2. Attach the dial indicator to spindle.
3. Feed the spindle down, with the dial pluger at operator’s right of left side until it registers about one-fourth of its operating range, and zero it.
4. Carefully rotate the spindle one revolution.
   (a)If the head and swiveling or semi universal type, the fore and aft readings in line with the cross feed will be identical; the right and left readings may vary if the head is not vertical.
   (b)If the head is of the universal type, the reading may vary on both axes.
5. Adjust a semi universal head by loosening the head and swiveling it so that the dial indicator reading is cut in half. Recheck the spindle and readjusting the head if necessary.
6. Universal heads should be adjusted in one plane at a time.
7. Securely tighten all head locking bolts and recheck.
   

Vise and Fixture Alignment
Vise alignment-the solid jaw of the vise is always the reference surface. The dial indicator is attached to the arbor of a horizontal milling machine or held in the collet of a vertical milling machine. The following procedure is suggested for aligning plates and other fixture with major flat surfaces

1. Clean all parts thoroughly. Make sure that there areno burrs or nicks on mating surface.
2. Lightly clam the vise or fixture in approximately the correct position.
3. Bring the dial indicator in contact with one end of the part to be aligned. Move in about one-forth of the indicator’s operating range and zero the indicator.
4. Move the table or cross slide the full length of the jaw or fixture.
5. Note the variation in indicator reading, and move the vise or fixture in the appropriate direction, using a soft hammer.
6. When the indicator shows no deviation, retighten all bolts and recheck.
   
   
   

Choosing A Milling Cutter

Selecting a milling cutter is not a simple task. There are many variables, opinions and lore to consider, but essentially the machinist is trying to choose a tool which will cut the material to the required specification for the least cost. The cost of the job is a combination of the price of the tool, the time taken by the milling machine, and the time taken by the machinist. Often, for jobs of a large number of parts, and days of machining time, the cost of the tool is lowest of the three costs.

Material :
High speed steel (HSS) cutters are the least-expensive and shortest-lived cutters. Cobalt steel is an improvement on HSS and generally can be run 10% faster. Carbide tools are more expensive than steel, but last longer, and can be run much faster, so prove more economical in the long run. HSS tools are perfectly adequate for many applications. The progression from HSS to cobalt steel to carbide could be viewed as very good, even better, and the best.

Diameter :
Larger tools can remove material faster than small ones, therefore the largest possible cutter that will fit in the job is usually chosen. When milling an internal contour, or concave external contours, the diameter is limited by the size of internal curves. The radius of the cutter must be less than or equal to the radius of the smallest arc.
Flutes: More flutes allows a higher feed rate, because there is less material removed per flute. But because the core diameter increases, there is less room for swarf, so a balance must be chosen.

Coating :
Coatings, such as Titanium nitride, also increase initial cost but reduce wear and increase tool life.

Helix angle :
High helix angles are typically best for soft metals, and low helix angles for hard or tough metals.

Types of Cutters

End mill
End mills (middle row in image) are those tools which have cutting teeth at one end, as well as on the sides. The words end mill are generally used to refer to flat bottomed cutters, but also include rounded cutters (referred to as ball nosed) and radiused cutters (referred to as bull nose, or torus). They are usually made from high speed steel(HSS) or carbide, and have one or more flutes. They are the most common tool used in a vertical mill.



Slot drill
Slot drills (top row in image) are generally two (occasionally three or four) fluted cutters that are designed to drill straight down into the material. This is possible because there is at least one tooth at the centre of the end face. They are so named for their use in cutting keyway slots. The words slot drill are usually assumed to mean a two fluted, flat bottomed end mill if no other information is given. Two fluted end mills are usually slot drills, three fluted sometimes aren't, and four fluted usually aren't.


Roughing end mill
Roughing end mills quickly remove large amounts of material. This kind of end mill utilizes a wavy tooth form cut on the periphery. These wavy teeth form many successive cutting edges producing many small chips, resulting in a relatively rough surface finish. During cutting, multiple teeth are in contact with the workpiece reducing chatter and vibration. Rapid stock removal with heavy milling cuts is sometimes called hogging. Roughing end mills are also sometimes known as ripping cutters.


Ball nose cutter
Ball nose cutters (lower row in image) are similar to slot drills, but the end of the cutters are hemispherical. They are ideal for machining 3-dimensional contoured shapes in machining centres, for example in molds and dies. They are sometimes called ball mills in shop-floor slang, despite the fact that that term also has another meaning. They are also used to add a radius between perpendicular faces to reduce stress concentrations.


Slab mill
Slab mills are used either by themselves or in gang milling operations on manual horizontal or universal milling machines to machine large broad surfaces quickly. They have been superseded by the use of Carbide tipped face mills that are then used in vertical mills or machining centres.


Side-and-face cutter
The side-and-face cutter is designed with cutting teeth on its side as well as its circumference. They are made in varying diameters and widths depending on the application. The teeth on the side allow the cutter to make unbalanced cuts (cutting on one side only) without deflecting the cutter as would happen with a slitting saw or slot cutter (no side teeth).


Involute gear cutter
The image shows a Number 4 cutter from an involute gear cutting set. There are 7 cutters (excluding the rare half sizes) that will cut gears from 12 teeth through to a rack (infinite diameter). The cutter shown has markings that show it is a

• 10 DP (diametrical pitch) cutter

• That it is No. 4 in the set

• that it cuts gears from 26 through to 34 teeth

• It has a 14.5 degree pressure angle

Hobbing cutter
These cutters are a type of form tool and are used in hobbing machines to generate gears. A cross section of the cutters tooth will generate the required shape on the workpiece, once set to the appropriate conditions (blank size). A hobbing machine is a specialised milling machine.


Face mill (indexable carbide insert)
A face mill consists of a cutter body (with the appropriate machine taper) that is designed to hold multiple disposable carbide or ceramic tips or inserts, often golden in color. The tips are not designed to be resharpened and are selected from a range of types that may be determined by various criteria, some of which may be: tip shape, cutting action required, material being cut. When the tips are blunt, they may be removed, rotated (indexed) and replaced to present a fresh, sharp face to the workpiece, this increases the life of the tip and thus their economical cutting life.


Fly cutter
A fly cutter is composed of a body into which one or two tool bits are inserted. As the entire unit rotates, the tool bits take broad, shallow facing cuts. Fly cutters are analogous to face mills in that their purpose is face milling and their individual cutters are replaceable. Face mills are more ideal in various respects (e.g., rigidity, indexability of inserts without disturbing effective cutter diameter or tool length offset, depth-of-cut capability), but tend to be expensive, whereas fly cutters are very inexpensive.


Woodruff cutter
Woodruff cutters make the seat for woodruff keys. These keys retain pulleys on shafts and are shaped as shown in the image.


Hollow mill
Hollow milling cutters, more often called simply hollow mills, are essentially "inside-out endmills". They are shaped like a piece of pipe (but with thicker walls), with their cutting edges on the inside surface. They are used on turret lathes and screw machines as an alternative to turning with a box tool, or on milling machines or drill presses to finish a cylindrical boss (such as a trunnion).

Milling Cutters

Milling cutters are cutting tools used in milling machines or machining centres. They remove material by their movement within the machine or directly from the cutters shape (a form tool such as a Hobbing cutter). Milling cutters come in several shapes and many sizes. There is also a choice of coatings, as well as rake angle and number of cutting surfaces. Below are the features of a cutter.

Shape :
Several standard shapes of milling cutter are used in industry today, which are explained in more detail below.

Flutes / teeth :
The flutes of the milling bit are the deep helical grooves running up the cutter, while the sharp blade along the edge of the flute is known as the tooth. The tooth cuts the material, and chips of this material are pulled up the flute by the rotation of the cutter. There is almost always one tooth per flute, but some cutters have two teeth per flute.[1] Often, the words flute and tooth are used interchangeably. Milling cutters may have from one to many teeth, with 2, 3 and 4 being most common. Typically, the more teeth a cutter has, the more rapidly it can remove material. So, a 4-tooth cutter can remove material at twice the rate of a 2-tooth cutter.

Helix angle :
The flutes of a milling cutter are almost always helical. If the flutes were straight, the whole tooth would impact the material at once, causing vibration and reducing accuracy and surface quality. Setting the flutes at an angle allows the tooth to enter the material gradually, reducing vibration. Typically, finishing cutters have a higher rake angle (tighter helix) to give a better finish.

Center cutting :
Some milling cutters can drill straight down (plunge) through the material, while others cannot. This is because the teeth of some cutters do not go all the way to the centre of the end face. However, these cutters can cut downwards at an angle of 45 degrees or so.

Roughing or Finishing :
Different types of cutter are available for cutting away large amounts of material, leaving a poor surface finish (roughing), or removing a smaller amount of material, but leaving a good surface finish (finishing). A roughing cutter may have serrated teeth for breaking the chips of material into smaller pieces. These teeth leave a rough surface behind. A finishing cutter may have a large number (4 or more) teeth for removing material carefully. However, the large number of flutes leaves little room for efficient swarf removal, so they are less good for removing large amounts of material.

Coatings :
Tool coatings can have a great influence on the cutting process The right coating can increase cutting speed and tool life, and improve the surface finish. Polycrystalline Diamond (PCD) is an exceptionally hard coating used on cutters which must withstand high abrasive wear. A PCD coated tool may last up to 100 times longer than an uncoated tool. However the coating cannot be used at temperatures above 600 degrees C, or on ferrous metals. Tools for machining aluminium are sometimes given a coating of TiAlN. Aluminium is a relatively sticky metal, and can weld itself to the teeth of tools, causing them to appear blunt. However it tends not to stick to TiAlN, allowing the tool to be used for much longer in aluminium.

Shank :
The shank is the cylindrical (non-fluted) part of the tool which is used to hold and locate it in the tool holder. A shank may be perfectly round, and held by friction, or it may have a Weldon Flat, where a grub screw makes contact for increased torque without the tool slipping. The diametre may be different from the diametre of the cutting part of the tool, so that it can be held by a standard tool holder.

Attachment and Accessories

Swivel Vise
6 1/2" Flame hardened Vise with swivel base

Universal Dividing Head
w/40 to 1 ratio Universal model with gears to drive from left side of machine table. Supplied with tailstock, indexing plates for manual operation rapid index featur and tailstock.

Infinite Variable Power Feed Unit

Way Covers
Covers are bellow design, made of neoprene coated material; Covers the ways top of knee and column.

Riser Block
Use to obtain clearance for very large workpieces. Riser blocks extends the height range 4"-8"-12" are easily mounted to the colulmn of the machine with four bolts.

Rotary Tables
These tables can be mounted either horizontally or vertically, suppolied with 3 dividing plates. A wide range of angular divisions can be made using a index plated having several circles of equal rotation of the workpiece to within 20 seconds of arc.

Slotter Tool Kit
Slotter Tool Kit with 7 shaping tools and 3 bit holders.

"Slotter" Vertical Shaping Attachment
The 3/4 HP vertical shaping head performs intricate shapes. Rear mounted, may be swung into place to perform light shaping operations. Adjusted to any vertical or compound angle to the table, can produce shapes which normally requires special broach. It is a must in cases of blind holes. It is mounted on the ram rear and can be rotated 180° to position it over the table for usage. 4" stroke from 80-420 spm.

Spindle

Lagun H.D. Geared Power Feeds
8 speed

Multi Angle Attachment
(all Angle Head)
Supplements the Right Angle Attachment. Any corner with a small radius can be finished milled. The unit is supplied with 3 collets of 1/8"-3/16-1/4". Rotational speed is increased 50%.
Available for R-8, #30, and #40 taper.

Power Draw Bars
Air operated

Precision Ground Ball Screws
X-Y with support

Right Angle Head
Designed to simplify right angle work by reducing the need of special tooling and difficult fixtures. Ideal for cavities and pocket jobs. It as aligning pads for quick positioning. Available for R-8, #30, and #40 taper.

Arbor Support and Mill Arbor
For use with right angle attachment for horizontal milling. Support features needle bearings.

Collet Chuck with 12 Collets
For 40 Taper

Digtial Read Out (DRO)
2,3, and 4 axis systems from Acu-rite®, Anilam®, Newallu®, and Sony®. Resolutions of 0.0005", 0.0002", or 0.0001 professionally installed.

Electric Power Draw-Bar

Erickson Quick Change Lock
Nut and Wrench

Milling Machine Care

Machines are almost same like human. Human needs care in order to have a better life and health, then this also can be applied to the machines. If we use a machine without caring about it, certainly it will break down someday. What if we do care about the machine? Will the machine's life span be longer? The answer for this question is YES! If a machine with good care, the performance of the machine will be as good as a new machine. Besides that, the life span will also be longer and this will save up the cost of getting a new machine. So here are some tips of taking good care of milling machine. Have a look below:


1.) Check and lubricate the machine with the recommended lubricants.

2.) Clean the machine thoroughly after each job. Use a brush to remove chips. Never attempt to clean the machine while it is running.

3.) Keep the machine clear of tools.

4.) Check each setup for adequate clearance between the work and the various parts of the machine.

5.) NEVER force a cutter into a collet or holder. Check to see why it does not fit properly.

6.) Use a sharp cutter. Protect your hands when mounting it.

7.) Have ALL guards in place before attempting to operate a milling machine.

8.) Start the machining operation only after you are sure that everything is in satisfactory working condition. It may be necessary to make special fixtures to hold odd shapes and difficult to mount work.

9.) Use attachments designed for the machine.

WARNING! Do NOT attempt to feel the machined surface while the cut is in progress or while the cutter is rotating. Stop the machine before making measurements and adjustments.

Precautions When Operating Milling Machine

Precaution is meant by a measure taken in advance to avoid danger in order to secure good result. When we handling a machine, precautions have to be taken in order to secure good result of the workpiece and personal safety. The precautions when operating milling machine as shown below:

1.) Avoid performing a machining operation on the milling machine until you are thoroughly familiar with how it should be done.

2.) Some materials that are machined produce chips, dust-, and fumes that are dangerous to your health. NEVER machine materials that contain asbestos, Fiberglass, beryllium, and beryllium copper unless you are fully aware of the precautions that must be taken.

3.) Maintain cutting fluids properly. Discard them when they become rancid or contaminated.

4.) Be sure the cutter rotates in the proper direction. Expensive cutters can be quickly ruined.

5.) Carefully store milling cutters, arbors, collets, adapters, etc., after each use. They can be damaged if not stored properly.

6.) Never start a cut unless you are sure there is adequate clearance on all moving parts!

7.) Exercise care when handling long sections of metal. Accidentally contacting a light fixture or busbar can cause severe electrical burns and even electrocution!

8.) Carefully read instructions when using the new synthetic oils, solvents, and adhesives. Many of them dangerous if NOT handled correctly.

9.) Use adequate ventilation for jobs where dust and fumes are a hazard. Return oils and solvents to proper storage. Wipe up spilled fluids. Do NOT pour used coolants, oil, solvents, etc., down a drain.

Milling Safety Practices

Milling machines, like all machine tools, should be cleaned after each work session. A medium width paint brush may be used to remove accumulated chips.

CHIPS are RAZOR SHARP; do NOT use your hand to remove them. NEVER remove chips with compressed air. The flying chips may injure you or a nearby person.

If cutting oil was used, the oily mist produced by the compressed air is highly flammable. If ignited by an open flame, it can produce explosive results. Finish by wiping down the machine with a soft cloth.

The following procedures are suggested for the safe operation of a milling machine.
Become thoroughly familiar with the milling machine before attempting to operate it. When in doubt, obtain additional instructions.

1.) Wear appropriate clothing and approved safety glasses!

2.) Stop the machine before attempting to make adjustments or measurements!

3.) Get help to move any heavy machine attachments, such as a vise, dividing head, rotary table, or large work.

4.) Stop the machine before trying to remove accumulated chips.

5.) Never reach over or near a rotating cutter!

6.) Be sure the work holding device is mounted solidly to the table, and the work is held firmly.

7.) Spring or vibration in the work can cause thin cutters to jam and shatter!

8.) Avoid talking with anyone while operating a machine tool, nor allow anyone to turn your machine on for you.

9. )Keep the floor around your machine clear of chips and wipe up spilled fluid immediately! Place sawdust or special oil absorbing compound on slippery floors.

10.) Be thoroughly familiar with the placement of the machine's STOP switch or lever.

11.) Treat any small cuts and skin punctures as potential infections! Clean them thoroughly. Apply antiseptic and cover injury with a bandage. Report any injury, no matter how minor, to your instructor or supervisor.

12.) Never "fool around" when operating a milling machine! Keep your mind on the job and be ready for any emergency!

Horizontal Milling Machine : Construction

The main parts of the horizontal mill are the base, column, knee, saddle, table, spindle, overarm and arbor supports. Below is the illustrations of a horizontal milling machines and it’s parts.




Column : The column of the milling machine, along with the base, are the major structural components. They hold, align, and support the rest of the machine.

Table : Holds and secures the workpiece for machining.

Saddle : The saddle is attached to the knee. The saddle provides the in and out, or Y axis table travel.

Knee : The knee supports the saddle and the table. The knee can be moved up and down for workpiece positioning.

Base : The base of the milling machine, along with the column, are the major structural components. They hold, align, and support the rest of the machine.

Spindle : The spindle holds the tool and provides the actual tool rotation.

Spindle Reverse Lever : The position of this lever determines the spindle direction. The three positions of the handle are In, Middle, and Out. The middle position is the neutral position. Never move the spindle reverse lever when the spindle is turning.

Spindle Speed Selection Lever : The spindle speed selection lever is used to change the spindle R.P.M. setting. This type of machine has a geared head so the spindle speed can only be changed when the spindle is stopped.

Spindle Clutch Lever : The spindle clutch lever engages the spindle clutch to the motor. By manipulating the spindle clutch lever the operator can start and stop the spindle.

Feed Rate Selection Lever : The feed rate selection lever is used to change the feed rate setting. The feed rate settings are expressed in inches per minute.

Motor Start and Stop Buttons : The motor start and stop buttons control the power to the main motor for the machine.

Clamps : The knee, table and saddle all come equipped with clamps. The clamps are used to maintain the position of their respective components. All of the clamps should be locked when machining, except the clamp for the axis that is moving.

Handles : The table and saddle handles are used to manually position the part with respect to the tool.

Knee Crank : The knee crank is used to raise and lower the knee.

Table Feed Directional Lever : The table feed directional lever establishes the direction of table feed. When the table feed directional lever is positioned to the left or right, the table will feed in that direction at the selected feed rate or at a rapid traverse rate when using the rapid traverse lever.

Saddle Feed Directional Lever- The saddle feed directional lever establishes the direction of in and out feed. When the saddle feed directional lever is positioned to the left or right, the table will feed in or out at the selected feed rate or at a rapid traverse rate when using the rapid traverse lever.

Lever : This lever is used to put the spindle in the Fast/Slow gear range. The Fast/Slow gear range lever allows the operator to select the speed range from which to set the R.P.M. setting from. Turn the spindle by hand while engaging this lever. This will help mesh the gears.

Draw In Bolt : The arbor draw in bolt draws the tool holder into the spindle. The arbor draw bolt is equipped with a jam nut to keep the draw in bolt from loosening up during operation.

Rapid Traverse Lever : The rapid traverse lever engages the rapid traverse gear on the feed motor. The rapid traverse is used for rapid table positioning. The appropriate feed direction lever must be engaged in order for the rapid traverse lever to be used.

Oil Flow Sight Gage : The oil flow sight gage assures to the operator that while the spindle is turning it is being properly lubricated. When the spindle clutch is engaged a steady flow of oil should be visible in this sight gage.

Oil Level Sight Gage : The oil level sight gage indicates the oil reservoir level. The oil level in this sight gage should be visible at all times.

Arbor Support : The arbor support supports the end of the arbor that is opposite the spindle. The arbor support is attached to the overarms bars.

Arbor Support Lock Nut : The arbor support lock nut fastens the arbor support to the overarm bars.

Overarm Bars : The Overarm bars align and support the arbor support.

Oil Reservoir : The oil reservoir holds and distributes oil to the overarm support bushing and arbor bearing collar. Proper lubrication and fit between the arbor bearing collar and the arbor support bushing are crucial.

Arbor Support Bushing Adaptor : The bushing adaptor comes in various sizes. The bushing adaptor allows the operator to use different size arbor support bushings in the same arbor support and also allows for slight adjustments for fit between the bushing and the collar.

Vertical Milling Machine : Construction

The main parts of the vertical milling machine are the base, column, knee, saddle, table, ram, and tool head. Below is the illustrations of the vertical milling machines and their parts.

Motor : The motor supplies the power to the spindle.

Toolhead : The toolhead houses the spindle. The toolhead is located at the end of the Ram. The toolhead also contains the motor.

Column : The column of the milling machine, along with the base, are the major structural components. They hold, align, and support the rest of the machine.

Table : Holds and secures the workpiece for machining.

Saddle : The saddle it attached to the knee. The saddle provides the in and out, or Y axis travel of the table.

Knee : The knee supports the saddle and the table. The knee can be moved up and down for workpiece positioning.

Ram : The ram allows the Toolhead to slide in and out. The ram gives the machine greater capacity and flexibility. It is recommended that the tool head be kept as close to the column as possible during heavy milling work.

Base : The base of the milling machine, along with the column, are the major structural components. They hold, align, and support the rest of the machine.



Clamps : The knee, table and saddle all come equipped with clamps. The clamps are used to maintain the position of their respective components. All of the clamps should be locked when machining, except the clamp for the axis that is moving.

Handles : The table and saddle handles are used to position the part with respect to the tool.

Oiler : The oiler feeds lubricant, under pressure, to the knee, table, and the saddle. Always give the oiler "one shot" before you begin operating the machine.

Knee Crank : The knee crank is used to raise and lower the knee.

Hi/Low Speed Range Switch : This is the spindle reversing switch. This switch and the Hi/Low gear lever work in conjunction to one another. Make sure that the switches are set alike to avoid mistakenly running the spindle backwards.

Speed Change Handwheel : This is the variable speed control. The handwheel works in conjunction with the spindle speed indicator. Do not turn this handwheel unless the spindle is running.

Spindle Brake : This handle engages the spindle brake. The handle can be moved in either direction to enable the brake. Never enable the brake with the spindle on.

Hi/Low Gear Change Lever : This lever is used to put the spindle in the Hi or Low gear range. Turn the spindle by hand while engaging this lever. This will help mesh the gears.

Quill Feed Handle : This is the handle you use to raise and lower the quill manually.

Quill Feed Selector : This crank is used to select the feed rate for the quill feed. The feed rates include 0.0015", 0.003", and 0.006" per revolution rates.

Power Feed Engagement Lever : This lever engages the power feed worm gear. When the lever is in the proper position, the power feed worm gear is engaged.

Feed Reverse Knob : The position of this knob determines the quill feed direction. The quill feed reverse knob position is influenced by the spindle direction. The three positions of the knob are; In, Middle, and Out. The middle position is the neutral position. Check the feed direction above the workpiece before engaging the power feed.

Feed Lever Control : The feed lever is a clutch which engages the quill feed. The quill feed will stay engaged until the quill stop comes in contact with the micrometer adjusting nut or the Feed Lever is released.

Quill Clamp : The quill clamp is a friction type clamp to be used when milling or anytime you don’t want the quill to move.

Quill : The quill contains the spindle assembly. The quill can be moved manually or by using the automatic quill feed.

Spindle : The spindle holds the tool and provides the actual tool rotation.

Arbor Draw Bolt : The arbor draw bolt draws the tool holder up into the spindle. The arbor draw bolt is equipped with a jam nut to keep the draw bolt from loosening up during operation.

Spindle Speed Change Dial : The spindle speed change dial is the spindle speed selector. On this type of milling machine the main power must be on to change speeds, but the spindle must be stopped.

Feed Rate Change Dial : The feed rate change dial is used to select the feed rate for the power feed table movement.

Table Feed Directional Lever : The table feed directional lever establishes the direction of table feed. When the table feed directional lever is positioned to the left or right, the table will feed in that direction at the selected feed rate or at a rapid traverse rate when using the rapid traverse lever.

Head Handwheel : The head hand wheel is used to hand feed or position the head up or down.

Head Clamp Lever : The head clamp lever locks or un-locks the head. The head should always be locked when ever it is not being positioned.

Spindle Starting Lever : The spindle starting lever starts the spindle. On some styles of vertical milling machines lifting the spindle handle may also start the feed motor. The spindle handle, when pulled down and held down, actuates the magnetic spindle brake.

Saddle Feed Directional Lever : The saddle feed directional lever establishes the direction of in and out feed. When the saddle feed directional lever is positioned to the left or right, the table will feed in or out at the selected feed rate or at a rapid traverse rate when using the rapid traverse lever.

Rapid Traverse Lever : The rapid traverse lever engages the rapid traverse gear on the feed motor. The rapid traverse is used for rapid table positioning. The appropriate feed direction lever must be engaged in order for the rapid traverse lever to be used.

Motor Start/Stop Buttons : The motor start and stop buttons control the power to the main motor for the machine.

~Various Pictures of Milling Machine~ n Tools~

Various types of Milling Machines~

Tools that used by milling machines~