Components of milling machines & function-Base, Column, Knee, Arbor, Saddle

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What is the milling machine? mention main parts used in milling machine.

• Milling is the process of removing material by high speed rotating tool against the workpiece with feed. milling machine mainly used in indutry for manufacturing parts, machining of parts, surface finishing of parts etc.
• Main parts of milling machine:

1. Base
2. Column
3. Knee
4. Overhanging arm
5. arbor
6. worktable
7. saddle

Components of milling machines

Anotomy of milling machines

Base

• foundation of milling machine on which whole machine loaded.

• This base is made of casting, due to which we get high co strength and load carriying capacity is high.
• It carries the column at its one end and also it's act as coolant reservoir.

column

• It also a hollow verticle supporting part of milling machine, which support parts like arbor, overhanging arm.
• Its mounted verticle on base. column also contain oil reservoir by which oil supply to all the axis.
• The front verticle face of column is accuretly machined and is provided with dovetail guide way for supporting the knee.

Arbor

• arbor is work as bearing, which use to provide support to the spindle.
• It is like an extension of the machine spindle on which milling cutters are securely mounted and rotated.
• The arbors are made with taper shanks for proper alignment with the machine spindles having taper holes at their nose. The draw bolt is used for managing for locking the arbor with the spindle and the whole assembly.
• The arbor assembly consits of the following componenets. arbor, spindle, spacing collars, bearing bush, cutter, draw bolt, lock nut, key block, set screw.

Overhanging arm

• It is mounted on the top of the column, which extends beyond the column face and serves as bearing support for the other end of the arbor.
• To support the projecting arbor, it can slide horizontally, forward and backward and adjusted at required position.

overhanging arm assembly,

Brace

• it is an extra support, which is fitted between the knee and the over arm to ensure further rigidity to the other end of the arbor.

yoke

• extra support, its used in some of milling machines.

spindle

• it is situated in the upper part of the column and receive power from the motor through belts, gears and clutches and transmit it to the arbor.
• In the spindle milling cutter is situated and spindle rotate at R.P.M. as motor rotated and remove material from workpice.

Knee

• Knee is rigid grey iron casting which slides up and down on the verticle ways of the column face.
• By operating the screw jack (elevating screw)with the help of hand wheel or power feed, the table height can be adjusted.
• With the movement of the knee the table height or distance between the cutter and workpiece can be adjusted.
• It contain gears and assembly by which machine's axis are moves. knee provide support to the saddle on which work table mounted.

Saddle

• Intermediate part between the table and knee which act as a support for the table.
• To provide cross feed to the table, the saddle can be adjusted crosswide along the guide ways provided on the top of the knee.
• Horizontal guide ways are provided at the top of the saddle along which the table can be moved in a longitudinal direction.

Table

• The table is rest on the saddle and travels longitudinally. A lead screw under the table engages a nut on the spindle to move the table horizontally by hand or power.
• In universal machines, the table may also be swiveled horizontally. For this pupose the table is mounted on circuler base.
• The top of the table is accuretly finished and T slots are provided for clamping the work and other fixtures on it. mainly T slot cutter used in milling machine

vice

• it is a work holding device, which hold the workpiece on table at time of operation.

Hand wheel

• In Manual milling machine various axis are moves by rotating hand wheel given for each axis. below some are mention that used for axis motion.
• Cross feed hand wheel: By this we can move table inward and outward.
• Table transverse hand wheel: By this we can able to move table left or right.
• Verticle knee transverse crank: This crank is useful to provide up and down motion of knee.

 

Conclusion

What is the main parts of a milling machine & his functions?

1. Base: Supporting structure of whole machine.
2. Column: verticle support for overhanging arm and his assembly.
3. Knee: It moves up and down across the column to provide up and down motion to the worktable.
4. Saddle: Intermediate part between the table and knee which act as a support for the table.
5. Work table: it is T slot bed on which workpiece are mounted.
6. Overhanging arm: provide support to the spindle
1. Arbor: work as bearing to provide support to the spindle
2. Brace: Support spindle knee side
3. Yoke
4. Spindle: spindle is used to rotate cutting tool at perticular R.P.M. to remove material.
5. Cutting tool: Cutting tool has ability to remove material from other surface.

FAQS

What are the 3 basic types of milling machine?

• Column and knee type milling machine
• Manufacturing type or fixed bed type milling machine
• planer type milling machine

What are the different types of CNC milling operations?

1. plain milling 
2. Face milling
3. End milling 
4.  Slot milling 
5. Form milling

What is the Function of arbor in milling machine?

Milling machine spindle are may be self holding and self releasing. for that in arbor there are one or three types of taper available to hold the spindle. 

1. Standard milling taper 
2. Brown and sharp taper 
3. Brown and sharp taper with Tang