Download - Turning Part Program
EA C412FMS
Topics to be covered today:• Turning Part Programming• Example
G-Codes
• Majority of the earlier codes still valid
• G40- TNR compensation cancel
• G41- TNR left compensation
• G42- TNR right compensation
• G70- Finish cutting CC
• G71- Rough cutting CC
• G76- Thread cutting canned cycle
Function Fanuc
Spindle speed mode
G96 –constant surface speed
G97-constant RPM
Feed rate mode G94 – IPM or mm/min
G95 –IPR or mm/rev
Inch/Metric dimension
G20 – all dimensions in inch
G21- all dimensions in mm
Return to HP G28
INTRODUCTION
Z-axis
X-axisTool
X-axis travel
Tool
Z-axis travel
Z-axis is the axis of the spindle and X-axis is the direction of traverse motion of the tool post
STEPS FOLLOWED(TURNING OPERATION)
• Move the cutting tool to a point near the job in the rapid mode
• Set linear interpolation (G01) and move in X-direction to give the required depth of cut
• Move along Z-axis to the required length of the job
• Set rapid mode (G00) and retract the tool along X-axis
• Move to the start point using G00 mode
EXAMPLE-1Taper turning
15 5 15
35
Dia 15Dia 20
Given: The raw material available is 20 mm dia bar of length 35mm.
The operations involved are:
• Facing
• Turn to 15 mm diameter over 15 mm length
• Taper turning
15 5 15
35
Dia 15Dia 20
N005 G50 S1100
N010 G21 G90 G94 EOB
N015 M03 S1000
N020 T0101 EOB
N025 G00 X22 Z0.5 EOB
N030 G01 X0 F200 EOB
N035 Z0 EOB
N040 X20 (FACING)
N045 X15 EOB
N050 Z-15 EOB
N055 X20 Z-20 EOB
N060 Z-35 EOB
N065 G00 X25 Z20
N070 M30 EOB
Here, M06 need not be used because the tool and the spindle are independent. So there is no reason to stop the spindle for tool change.
G50 code followed by S1100 sets the maximum RPM of the spindle. This is the rated speed of the machine.
T0101 : - The tool offsets (length compensation)
EXAMPLE-2
20 5 10
R5
R520
N00 G90 G21 G94 EOB
N01 G28 U0 W0N02 T0404N03 M03 S1200
N04 G00 X0 Z1 EOB
N05 G01 Z0 F100 EOB
N06 G02 X10 Z-5 I0 K-5 F150 EOB
N07 G01 Z-15 EOB
N08 G03 X20 Z-20 I5 K0 EOB
N09 M30 EOB
Note that I have not used nose radius compensation. It has to be used here.
Tool Nose Radius Compensation
• The cutter compensation helps in making minor adjustments to the tool tip position in order to accurately produce machine features.
• Cutter compensation behaves differently based on whether tool tip programming or tool center programming is being used.
Tool center programming
G42
G41
With tool center programming, the tool will be automatically offset by the radius value that has been entered into the offset registry.
All surfaces will be affected with this mode
Tool tip programming
• With tool tip programming, only tapers and radii will be affected.
• Straight diameters and perpendicular faces will remain unchanged.
Error in profile
G71Multiple Turning CC
• A G71 causes the profile to be roughed out by turning.
• You need two blocks to specify all the values.• Example G71 U2.0 R1.5• G71 P10 Q20 U0.1 W0.1 F45
(i) U0.5 R1
U- Depth of cut in each pass along X-axis in mm
R- Retraction or retardation amount in mm
(i) G71 P_ Q_ U_ W_ F_
• Example G71 U2.0 R1.5• G71 P10 Q20 U0.1 W0.1 F45
(i) U0.5 R1 U- Depth of cut in mm R- Retraction or retardation amount in mm
(ii) G71 P_ Q_ U_ W_ F_
P- Starting block number
Q- End block number
U- Finishing allowance along X-axis in mm
W- Finishing allowance along Z-axis in mm
F- Feed rate
G70Finish Turning CC
• A G70 causes a range of blocks to be executed.
• This is used after compilation of G71.
• It has only one block.
• G70 P10 Q20
P- First block of cycle
Q- Last block of cycle
G72Multiple Facing CC
• A G72 causes the profile to be roughed out by facing.
• You need two blocks to specify all the values.• Example G72 W2.0 R1.5• G72 P10 Q20 U1.0 W1.0 F45(i) W2.0 R1.5
W- Depth of cut in each pass along Z-axis in mm R- Retraction or retardation amount in mm
(i) G72 P_ Q_ U_ W_ F_
• Example G72 W2.0 R1.5• G72 P10 Q20 U1.0 W1.0 F45(i) W2.0 R1.5 W- Depth of
cut in each pass along Z-axis in mm R- Retraction or retardation amount in mm
(ii) G72 P_ Q_ U_ W_ F_P- Starting block numberQ- End block numberU- Finishing allowance along X-axis in mmW- Finishing allowance along Z-axis in mmF- Feed rate
G76Threading Cycle
• G76 is a multi-pass threading cycle.
• Here also two blocks are required.
• G76 P031560 Q150 R0.5• G76 X17.96 Z-50 P1020 Q250 F1.5
• G76 P031560 Q150 R0.5• G76 X17.96 Z-50 P1020 Q250 F1.5
Code Meaning
P03 No of finishing passes
15 Pull out angle
60 Angle of thread
Q150 1000XMin depth of cut in mm (Here 0.150)
R0.5 Finishing allowance in mm
X17.96 Core diameter of thread
Z-50 Length of thread
P1020 1000XHeight of thread in mm (Here it is 1.020)
Q250 1000XDepth of first cut in mm (Here it is 0.25)
F1.5 Pitch or Lead of thread
Data table
O/DIA CORE PITCH DEPTH
1.6 1.1706 0.35 0.2147
For a metric thread
H=0.866Xp
EXAMPLE-1
20
10 5 10 10 10 5
102030
[BILLET X30 Z50]
N010 G21 G40 G98
N020 G28 U0 W0
N030 T0404
N040 M03 S1200
N050 G00 X30 Z5
N060 G00 Z1
N070 G71 U0.5 R1
N080 G71 P90 Q150 U0.1 W0.1
Note that I have not used nose radius compensation. It has to be used here.
EXAMPLE-1
20
10 5 10 10 10 5
102030
N090 G01 X0
N100 Z0
N110 G03 X10 Z-5 R5
N120 G01 Z-15
N130 X20 Z-25
N140 G01 Z-35
N150 G02 X30 Z-40 R5
(# Finishing Cycle)
N160 G70 P90 Q150
N170 G28 U0 W0
N180 M05
N190 M30