11. • Thin jobs can be held by means of
magnetic chucks.
Collet Chuck
Magnetic Chuck
Collet chuck isCollet chuck is
used to hold smallused to hold small
workpiecesworkpieces
Thin jobs can beThin jobs can be
held by means ofheld by means of
magnetic chucks.magnetic chucks.
12. Three jaw chuck
- For holding- For holding
cylindrical stockcylindrical stock
centered.centered.
- For facing/center- For facing/center
drilling the end of yourdrilling the end of your
aluminum stockaluminum stock
Four-Jaw Chuck
- This is independent
chuck generally has four
jaws , which are
adjusted individually on
the chuck face by means
of adjusting screws
42. Drilling And Drills
Types of drills
– Twist drill: most
common drill
– Step drill:
produces holes
of two or more
different
diameters
– Core drill: used
to make an
existing hole
bigger
66. Top
View
Front
View
Tool At Home
O0001
N005 G54 G90 S600 M03
N005 Sequence Number
G54 Fixture Offset
G90 Absolute Programming Mode
S600 Spindle Speed set to 600 RPM
M03 Spindle on in a Clockwise Direction
67. Top
View
Front
View
O0001
N005 G54 G90 S600 M03
N010 G00 X1.0 Y1.0
G00 Rapid Motion
X1.0 X Coordinate 1.0 in. from Zero
Y1.0 Y Coordinate 1.0 in. from Zero
68. Top
View
Front
View
O0001
N005 G54 G90 S600 M03
N010 G00 X1.0 Y1.0
N015 G43 H01 Z.1 M08
G43 Tool Length Compensation
H01 Specifies Tool length compensation
Z.1 Z Coordinate .1 in. from Zero
M08 Flood Coolant On
69. Top
View
Front
View
O0001
N005 G54 G90 S600 M03
N010 G00 X1.0 Y1.0
N015 G43 H01 Z.1 M08
N020 G01 Z-.75 F3.5
G01 Straight Line Cutting Motion
Z-.75 Z Coordinate -.75 in. from Zero
F3.5 Feed Rate set to 3.5 in./min.
70. Top
View
Front
View
O0001
N005 G54 G90 S600 M03
N010 G00 X1.0 Y1.0
N015 G43 H01 Z.1 M08
N020 G01 Z-.75 F3.5
G00 Rapid Motion
Z.1 Z Coordinate .1 in. from Zero
M09 Coolant Off
N025 G00 Z.1 M09
71. Top
View
Front
View
O0001
N005 G54 G90 S600 M03
N010 G00 X1.0 Y1.0
N015 G43 H01 Z.1 M08
N020 G01 Z-.75 F3.5
N030 G91 G28 X0 Y0 Z0
G91 Incremental Programming Mode
G28 Zero Return Command
X0, Y0, Z0
X,Y,& Z Coordinates at Zero
N025 G00 Z.1 M09
72. Top
View
Front
View
O0001
N005 G54 G90 S600 M03
N010 G00 X1.0 Y1.0
N015 G43 H01 Z.1 M08
N020 G01 Z-.75 F3.5
N035 M30
N030 G91 G28 X0 Y0 Z0
N025 G00 Z.1 M09
M30 End of Program
In this case, we are using a simple analogy to stress how a programmer must be able to visualize a CNC program’s execution. We first look at how a machinist would machine a hole in a work piece held in a vise on a milling machine. Then we’ll show how the same operation will be performed with a CNC program.
The machinist standing in front of the milling machine has everything they need right in front of them. They wouldn’t forget something as simple as turning the spindle on before trying to drill the hole. On the other hand, a CNC programmer must typically work with nothing more than a blueprint, a pencil, a calculator, and a blank piece of paper. They must be able to visualize every motion and function of the program’s execution in their minds.
Here is the same operation (drilling a hole) performed by a CNC program. Each step will be explained.