CNC Grinding Machine

1. Metal Removal Process
ASSIGNMENT

3. What is CNC Machine?
 Computerized Numerical Control
 Comprises of the computer in which the
program is fed for cutting of the metal of
the job as per the requirements

4. Components of CNC
Machine
 Coding
 Input device
 MCU
 Drive System
 Machine tool
 Feedback System

6. Functions of CNC
 Control function (control the axes)
 Interpolation function(trajectory)
 Feed function
 Spindle function (spindle speed)
 Auxiliary functions(stopping and steering)
 Tool function( select desired tool)
 Graphic display function(CRT or LCD)
 Self-diagnostic function (caution from failure)
 Communication function (to adapt FMS)

7. Motion of grinding wheel
 Grinding wheel can follow any linear
path in X Y Z direction
 Along with that it can rotate about a
fixed axis of rotation only in one
direction
 But the axis of rotation can be adjusted
in three-dimensions

8. The types of work pieces and operations typical of grinding:
(a) cylindrical surfaces, (b) conical surfaces. (c) fillets on a
shaft, (d) helical profiles, (e) concave shape, (f) cutting off
or slotting with thin wheels, and (g) internal grinding.

9. Recirculating Ball Screw
Mechanism for Table movement
 Widely used in CNC tools
 The thread form used is Gothic arch

10.  The balls rotate between the screw
thread and the nut, and recycle around
the thread.

11.  The efficiency of the recirculating ball
screws is about 90%
 Movement is obtained by the rolling
motion of the balls between the screw
and the nut
 The balls put pressure on opposite sides
to allow bi-directional motion of table
 The table can move in 2 perpendicular
axes

12. Stepper Motor
It is used in Grinding Machines
 downfeeding grinding wheel
 automatic wheel dressing
Diagram of a typical
stepper motor

13.  Stepper Motor is used to control the axis
of the rotating grinding machine
 The toothed electromagnets present
inside the motor gets attracted to the
gear teeth, when given charge.
 This divides the motion into no. of equal
steps
 Optical encoder is used in the feedback
system to observe and control the rotary
motion of the grinding wheel

14. Thank you