Activity 2.3.3 G Code
Introduction
In this activity you will learn how to communicate with a CNC machine. You will
practice reading and interpreting G Codes.
Equipment
 Pencil
 Computer with CNC Base
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Computer Integrated Manufacturing Activity 2.3.3 G Codes – Page 1
Use the grid below to draw a set of straight lines and arcs to create capital alphabetical characters for your initials (first, middle, and
last), marking all endpoints and centerpoints on the grid intersections. Design must contain a minimum of 3 arcs. We will use a 1/8
in. end mill to produce the initials. Note: The grid consists of 1/16 in. spaces. Remember to consider tool cutter compensation so that
each letter will end after milling with a dimension of 1.50 x 0.75 in. Label each of the significant points in your design with an
alphabetical letter. Chart each of the significant coordinates in the table below using absolute coordinates. Note: Remember to
record arc center points as well as end points.
© 2013 Project Lead The Way, Inc.
Computer Integrated Manufacturing Activity 2.3.3 G Codes – Page 2
Coordinates for Straight and Curved Letter Initials Using Linear and
Circular Interpolation
Absolute Coordinates
Point
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
AA
BB
CC
DD
EE
FF
GG
HH
II
JJ
KK
LL
MM
NN
OO
X
Absolute Coordinates
Y
Point
PP
QQ
RR
SS
TT
UU
VV
WW
XX
YY
ZZ
AAA
BBB
CCC
DDD
EEE
FFF
GGG
HHH
X
Y
© 2013 Project Lead The Way, Inc.
Computer Integrated Manufacturing Activity 2.3.3 G Codes – Page 3
NC Code – Straight & Curved Letter Initials –
Linear & Circular Interpolation
Absolute Coordinates
Write G&M code that would allow a 1/8 in end mill tool to create
the design using absolute coordinates.
Bloc
k
G
X
Y
Z
I
J
Safe Position
Cut Increment
Spindle Speed
Feed Rate
Plunge Feed Rate
Tool 6
R
F
M
0.1 Above Material
0.0625
3000 RPM
18 IPM
9 IPM
1/8 End Mill
T
S
; Comments
%
O00001
N00
G17 G20 G28 G40 G49 G80 G90
(Safe start)
N10
N20
M06
G43 H06
N30
N40
M03
G54 G00
N50
N60
N70
(Tool Change – Tool 6 -1/8
End Mill)
T06
X
Y
(Spindle On CW – Speed
3000 RPM)
(Rapid to Above Point A)
Z0.1
G01
S3000
Z -0.0625
(Rapid to 0.1 Above Part)
F9.
(Plunge 1/16 @ 9 in./min)
F18.
(Cut to point B)
© 2013 Project Lead The Way, Inc.
Computer Integrated Manufacturing Activity 2.3.3 G Codes – Page 4
Block
G
G01
X
Y
Z
Z.1
I
J
R
F
M
F9.
T
S
; Comments
(Retract from part)
G28
(Go to machine zero)
M30
(Rewind program)
%
© 2013 Project Lead The Way, Inc.
Computer Integrated Manufacturing Activity 2.3.3 G Codes – Page 5