G68 Coordinate Rotation issue...

[TheDane]

Hi there,

I'm having some trouble getting the G68 rotating function working properly.

I want to mill this slot, turn 120 degrees, mill it again, and turn it another 120 degrees and mill it the last time.

But how come I get a CRC alert no. 41 when I'm milling the 3. (240degree) slot?

Here's my program:

:0070(WELDINGFIXTURE)
(S)(HMT)(JENS)
G1902 B188. D157.5 H20. I94. J78.75 K0.

T22 (6MM.SGS.END-MILL)
M6
G0 G90 G54.1 P20 X0 Y0 S8000 M3
G43 Z3 H22 D22 M8
M98 P0071
G68 X0 Y0 R120
M98 P0071
G68 X0 Y0 R240
M98 P0071
G69
G0 G90 Z250 M9
G0 G91 G28 Z0 Y0 M5
M30

:0071 (SUBPROGRAM FOR SLOT)
G0 X0 Y-4
G0 Z-6
G1 Y-16.775 F400
G1 Y-10
G1 G41 X1.51 Y-13.51
G3 X5.01 Y-10 R3.5
G1 Y0 ,R3
G1 X-5.01 ,R3
G1 Y-16.775
G3 X5.01 Y-16.775 R5.01
G1 Y-10
G3 X1.51 Y-6.5 R3.5
G1 G40 X0 Y-10
G0 Z3
G0 X0 Y0
M99

Shouldn't it just work like a charm? Controller is a Fanuc MXP-200i

Thanks

Soren

[ggborgen]

Try canceling the rotation after the 120 slot.
G69
G68X0Y0R240

[sinha_nsit]

post the drawing.

It is difficult to believe that the second slot is correctly made, but not the third one, since the codes are same.

[Andre' B]

It worked in my back plotter after I added decimal points.

:0070(WELDINGFIXTURE)
(S)(HMT)(JENS)
G1902 B188. D157.5 H20. I94. J78.75 K0.

T22 (6MM.SGS.END-MILL)
M6
G0 G90 G54.1 P20 X0 Y0 S8000 M3
G43 Z3 H22 D22 M8
M98 P0071
G68 X0 Y0 R120.         (Added DP)
M98 P0071
G68 X0 Y0 R240.         (Added DP)
M98 P0071
G69
G0 G90 Z250 M9
G0 G91 G28 Z0 Y0 M5
M30

:0071 (SUBPROGRAM FOR SLOT)
G0 X0 Y-4.         (Added DP)
G0 Z-6.         (Added DP)
G1 Y-16.775 F400
G1 Y-10.         (Added DP)
G1 G41 X1.51 Y-13.51
G3 X5.01 Y-10. R3.5         (Added DP)
G1 Y0 ,R3
G1 X-5.01 ,R3
G1 Y-16.775
G3 X5.01 Y-16.775 R5.01
G1 Y-10.         (Added DP)
G3 X1.51 Y-6.5 R3.5
G1 G40 X0 Y-10.         (Added DP)
G0 Z3
G0 X0 Y0
M99

[Andre' B]

Screen shot.

[sinha_nsit]

Without decimal points, even the second slot should have problems.
Howcome he has problem only with the third slot?

[Andre' B]

Without decimal points, even the second slot should have problems.
Howcome he has problem only with the third slot?

I have no idea.
But to be overly critical he does not say that he tried it at 0 and 120, we are just assuming that from the program.