Problems with G72 canned cycle
Posted: Thu 10 Dec , 2009 12:32 pm
Hi,
I wonder if anyone could help me with a quick query.
I'm currently learning to use G code programming on my Novaturn but am struggling a little with the G71 and G72 canned cycle commands.
The program below carries out a G71 command to profile the outer surface of a round bar and seems to work ok.
I'm then changing tool to Tool 4 which is an end profiling tool which I am describing as boring bar with a left tip orientation.
The last seven lines of the program call the G72 command. What I'm trying to do is initially machine a straight sided pocket in the end but then to leave a pip of material standing up in the centre.
When I run this on a 2D simulation the pip is clearly visible until the last cycle of the program when it is removed. Can anyone explain why this is happening? Has it got anything to do with type I and II cycles?
I know that the pocket won't be straight sided as the shape of the tool tip will machine out extra material, but if I can get this working I make be able to modify the shape of the pocket later to offset this.
Please excuse my program if it is not very well written as I have a lot to learn!
G21
[BILLET X25.4 Z60
G28 U0 Z80
G98 G97 S3500
M06 T0101
G00 X25 Z2 M03
G71 U0.1 R-0.2
G71 P1 Q2 U0.01 W0.1 F50
N1 G00 X10
G01 Z0 F500
G03 X25 W-35 R80
N2 X25 Z-20
G28 U0 W0
M06 T0401
G00 X10 Z0.5
G72 W0.2 R0.3
G72 P3 Q6 U0.1 W0.1 F50
N3 G01 Z-5
N4 G01 X2.5
N5 G01 X0 Z-2.5
N6 G01 Z0.5
I wonder if anyone could help me with a quick query.
I'm currently learning to use G code programming on my Novaturn but am struggling a little with the G71 and G72 canned cycle commands.
The program below carries out a G71 command to profile the outer surface of a round bar and seems to work ok.
I'm then changing tool to Tool 4 which is an end profiling tool which I am describing as boring bar with a left tip orientation.
The last seven lines of the program call the G72 command. What I'm trying to do is initially machine a straight sided pocket in the end but then to leave a pip of material standing up in the centre.
When I run this on a 2D simulation the pip is clearly visible until the last cycle of the program when it is removed. Can anyone explain why this is happening? Has it got anything to do with type I and II cycles?
I know that the pocket won't be straight sided as the shape of the tool tip will machine out extra material, but if I can get this working I make be able to modify the shape of the pocket later to offset this.
Please excuse my program if it is not very well written as I have a lot to learn!
G21
[BILLET X25.4 Z60
G28 U0 Z80
G98 G97 S3500
M06 T0101
G00 X25 Z2 M03
G71 U0.1 R-0.2
G71 P1 Q2 U0.01 W0.1 F50
N1 G00 X10
G01 Z0 F500
G03 X25 W-35 R80
N2 X25 Z-20
G28 U0 W0
M06 T0401
G00 X10 Z0.5
G72 W0.2 R0.3
G72 P3 Q6 U0.1 W0.1 F50
N3 G01 Z-5
N4 G01 X2.5
N5 G01 X0 Z-2.5
N6 G01 Z0.5