[glovebox20-2]

Hello.

I was hoping some could tell me the best way to cancel G43 with no spindle movement on a Fanuc 18im 5-face bridge mill. Right now, I came up with is 'G49 G91 X#5081 Y#5082 Z#5083'. The #508* variables are the tool length offset value for each axis.

I've tried using G49 by it self, but then the spindle may want to move the value of the tool length offset for each axis, witch may cause the mill to crash when using the 5-face head/right angle attachment. And without canceling the G43, I can't use G68 to rotate my coordinate system without generating an alarm or properly positioning the head to the new work plane. I also dont want to use 'G49 G90 Z10.0000' because by not knowing the exact offset value, that may cause the spindle to crash in the part.

Thanks

Sent from my XT1080 using Tapatalk

[STLMachinist]

Try changing PRM 5006#6=1. This should only change the numbers on the screen, not move the axes.

Attachment 330980

[glovebox20-2]

Try changing PRM 5006#6=1. This should only change the numbers on the screen, not move the axes.

I can give it a shot. The problem I am having is when I'm using 3d-coordinate system rotation with the 5-face head, the head is moving unexpectedly. So I started screwing around, and wrote the variables #5081-#5083 to #101-#103 at different spots in the program so I could see what was happening to the tool length offset Value....

%
O10 (H-HEAD TEST)

G0 G28 G91 Z0
T1 M6 (DRILL HOLES WITH V-SPINDLE)
G0 G90 G57 X0 Y0 S1200 M3
G43 Z3.5 H1 (#5083, TOOL LENGHT COMP IN Z = TOOL LENGTH VALUE)

X0 Y-1.5
Z1.5
G81 Z-.15 R.05 F15.
Y-2.5
X2.5
Y-1.5
G80 Z3.5

G0 G28 G91 Z0 M5 (#5083=0)
G49

M61 (INSERT H-HEAD)
T1 M6 (3/8 SPOT)
M60C0. (ROTATE HEAD TO 0*)
G0 G54 G90

(TRANSULATE WORK PLANE)
G68 X0 Y0 Z0 R#3
G68 X0 Y-8.245 Z0 I0 J1 K0 R90

G43 X0 Z3.5 H1 S1200 M3 (#5083= TOOL LENGHT VALUE)
Y-1.5

X0 Y-1.5
Z1.5
G81 Z-.15 R.05 F15.
Y-2.5
X2.5
Y-1.5
G80 Z3.5

69 (#5081, TOOL LENGTH COMP IN THE X AXIS = TOOL LENGTH VALUE, #5083 = 0)
G0 G28 G91 Z0 M5

G49 {HEAD MOVES UNEXPECTEDLY IN X)

M60C90. (INDEX HEAD TO 90*)

G0 G55 G90

(TRANSULATE WORK PLANE)
G68 X0 Y0 Z0 R#3
G68 X0 Y-8.245 Z0 I0 J1 K0 R90

G43 X0 Z3.5 H1 S1200 M3 (#5083, TOOL LENGTH COMP IN THE Z AXIS = TOOL LENGTH VALUE)
Y-1.5

X0 Y-1.5
Z1.5
G81 Z-.15 R.05 F15.
Y-2.5
X2.5
Y-1.5
G80 Z3.5

G69 (#5082, TOOL LENGTH COMP IN THE Y AXIS = TOOL LENGTH VALUE, #5083 = 0)
G0 G28 G91 Z0 M5

M60C90. (INDEX HEAD TO 180*)

G0 G56 G90

(TRANSULATE WORK PLANE)
G68 X0 Y0 Z0 R#3
G68 X0 Y-8.245 Z0 I0 J1 K0 R90

G43 X0 Z3.5 H1 S1200 M3 (HEAD NOT POSITION CORRECTLY IN Y)
Y-1.5

X0 Y-1.5
Z1.5
G81 Z-.15 R.05 F15.
Y-2.5
X2.5
Y-1.5
G80 Z3.5

G0 G28 G91 Z0 M5
G69 (#5081-#5083 ARE ALL 0)
G49 (NO SPINDLE MOVEMENT)
M30
%

One easy solution I see is canceling the 3D coordinate system ration after the G0 G28 G91 Z0 line. However, If I restart the program after an interruption, bad things can happen as the tool length comp has not been properly canceled. And if I don't know what axis has the comp value applied to it, It's just a guessing game. So the easiest, sure fire way to cancel it with no spindle movement is 'G49 G91 X#5081 Y#5082 Z#5083' after canceling G68 and before any Coordinate system change (G43, G54, G68, ect)

I just bothers me because in the machine tool builder manual (Kao-Ming) shows G69 being used before G0 G28 G91 Z0, witch is causing me problems. Not sure how they were able to make the sample part in the book with crashing. I've loaded it in the machine and did a dry run and......Crash!!!! How is one supposed to make a good post for Cam software base on this information? Trail and error i guess......

[glovebox20-2]

Try changing PRM 5006#6=1. This should only change the numbers on the screen, not move the axes.

Thanks for the Tip, that did the trick :rainfro:

However, 'G49 G91 X#5081 Y#5082 Z#5083' will cause spindle movement with this setting turned on. 'G49' by itself will not.


The nice thing about changing this parameter is now can go t MDI and execute 'G43 H1' and my Absolute Position will now display the distance from the tool to the part, with no spindle movement.