CNC milling machines use computerized controls and rotating cutting tools to remove material from a workpiece. There are two main types - horizontal and vertical milling machines - classified based on the orientation of the spindle axis. Milling operations include planer milling (point-to-point and straight cuts) and contour milling. Common planer milling operations are end milling, face milling, drilling and boring, while contour milling is used for profile milling.

1. CNC MILLING MACHINE
OPERATIONS

2. CNC Milling Machine
• CNC milling, is a machining process
which employs computerized
controls and rotating multi-point
cutting tools to progressively remove
material from the workpiece in the
form of chips and produce a final
part.

3. Milling Process
• Milling is the process of machining using
rotary cutters to remove material by
advancing a cutter into a workpiece.
• The milling cutter is a rotary cutting tool,
often with multiple cutting points.
• The cutter in milling is usually moved
perpendicular to its axis so that cutting
occurs on the circumference of the cutter.
(but in drilling, the tool is advanced along its
rotation axis).

4. Milling Machine – Spindle axis
• Main classification of milling machine
is based on its spindle axis.
• According to the spindle axis milling
machines are classified into two
main types.
–Horizontal Milling machines
–Vertical Milling Machines

5. Vertical Vs Horizontal Milling Machines

6. • Base of both milling machines supports the entire machine.
• Column also a structural member which houses the knee, spindle,
bearing, gear box, clutches, shaft, pumps, power transmission
mechanism for motor to spindle, etc.
• Knee mounted in front of the column is for supporting the table and to
provide an up or down motion along the Z axis.
• Saddle consists of two slideways, located at 90º to each other, for
providing motions in the X & Y axes by means of lead screws.
• Table is mounted on top of the saddle and can be moved along the X
axis. T slots on top of the table used for mounting / clamping workpiece.
• Arbor is an extension of the spindle for mounting cutters.
• Milling head consisting the spindle, the motor, and the feed control unit
is mounted on a swivel base such that it can be set at any angle to the
table.
• Ram on which the milling head is attached can be positioned forward
and backward along the slideways on the top of the column.
Vertical Vs Horizontal Milling Machines

7. Milling Vs Lathe Machines
Milling Lathe
Usually used to
machine flat surfaces
Usually used to
machine cylindrical
surfaces
Cutter rotates against
moving workpiece
Workpiece rotates
against the moving
cutting tool
Usually multi point
cutting tools used
Usually Single point
cutting tools are used

8. Up Milling Vs Down Milling
Up Milling Down Milling
cutter rotates in a
direction opposite to the
table feed.
cutter rotates in the same
direction as the table
feed.

9. Plain Milling
• Plain milling is the milling of a flat surface with the
axis of the cutter parallel to the machining surface.
Horizontal milling Vertical milling

10. End Milling
• End Milling is the milling of a flat surface with the axis
of the cutter perpendicular to the machining surface.
Horizontal milling Vertical milling

11. CNC Milling machine Types
• CNC Milling machines are mainly
classified in to three types;
1. Horizontal machining center
2. Vertical machining center
3. Universal machining center

12. 1. Horizontal machining center

13. 2. Vertical
machining center
3. Universal
machining center

14. CNC Milling machine operations
• Main operations of CNC Milling machine is
classified in to two types;
 Planer Milling
 Contour Milling

15. Planer Milling Operations
• Planer milling operations involves point to point
and straight cut motion control systems.
• Operations under planer milling which involves
straight cut motion control system includes, end
milling, face milling, plain milling, chamfer milling
and boring (by interpolation).
• Operations under planer milling which involves
point to point motion control system involves
drilling, boring, counterboring, countersinking,
reaming and tapping.

16. Point to point control CNC Milling Operations
Drilling
CBR
CSK
Taping
Reaming

17. Straight cut control CNC Milling Operations
Pocketing Facing Slotting
Chamfering Boring

18. Contour Milling Operations
• Contour milling operations involves profile milling
of cavities & Cores, Contour area machining, and
machining of profile corners, etc.
XY control - Roughing
ZX / ZY control - Finishing