[CMK1]

Hello
I have a problem on a fanuc 6mb with the work offsets G54-G59
They wont work.
If i set any work offset to any position
and in mdi give it G0 G90 G54 X0.0 Y0.0
it will just sit there
we have bought this machine at auction
so it possible someone has been playing with the paramaters
i have tried everything i can think of so any help
will be gratefully appreciated

[mactec54]

Hi CMK1

Try putting the G90G54G0X.0Y.0
another way also
G54
G90G0X.0Y.0
If this does not work there my be something wrong in the control Parameters Etc

[CMK1]

Thanks but i have already tried it like that
and it still does not work
what paramaters should i check?

[ckirchen]

What happens if you enter G0 G90 G54 X1.0 Y1.0?

[CMK1]

I think it will move +1.0mm from its current position
I will double check in the morning

[ckirchen]

If it does that, it means that MDI is in incremental mode. MDI is overriding your G90.

In MDI, do you see an ABS or an INC at the bottom right of the screen? If you see an INC, press the ABS/INC button (top left) until you see ABS and try entering your line again.

I would have thought that if you specify G90 in an MDI block it would designate absolute and override the ABS/INC selection, but I guess not.

The reason G0 G90 G54 X0.0 Y0.0 didn't cause any montion is because, in incremental terms, you told the controller not to move.

Chris Kirchen

[stevo1]

I have never seen the MDI mode be incremental no matter what you program. But I have not had much experience on the 6 series control. Just to clear the stupid question up…when you set your G54 say as your current machine position you then move the tool off that position before programming G54X0Y0 correct?

Does this machine do everything else correctly? You have the machine referenced home?

I would try running it in a program instead of MDI to clear up any problem of incremental in MDI mode that Chris was referring to.

So you say if you program G0G90G54X1Y1 it will move X1 & Y1 So what happens if you program:
G0G90G54X1Y1;
X0Y0;
Will the machine only do the first line then not execute returning back to 0,0? You say you have tried everything so I assume you tried using G55-G59 as well?

I don’t have a 6 series manual but skimming through some of my parameter manuals I found parameter 2402 bit 1 that refers to manual intervention for absolute and incremental and if set to 1 it has a note about the Fanuc 6 series. It might be worth checking out.

Stevo

[mactec54]

Hi CMK1

Have you tryed as ckirchen has done the Gcode with a space

G0 G90 G54 X 1.0 Y 1.0 some of the funuc controls like to see a space in the code

& also a G10 can be used for offset value setting in some controls

[CMK1]

Have found another few problems maybe there all related

1 when using a G84 tapping cycle it will go to the bottom of the
hole reverse the spindle but it will not retract the z out of the hole
it just sits revolving the spindle in reverse at the bottom of the hole

2 when using G28 to move to tool change position in Z it is 5mm out of position
from looking at programs already in the machine and speaking to the programer that had operated it this had been working ok
(Maybe only a parameter adjustment)

3 I can origin out the absolute positions on all 3 axis at any stage even in auto
I dont think this should happen.

4 If i power up the machine then refernce the axis
put in a work offset of X-500 Y-150
in mdi give it G0 G90 G54 X0.0 Y0.0
it will move to that position ok
but then if i move the axis manualy out of position say 100mm on each axis
then go back to mdi and key in G0 G90 G54 X0.0 Y0.0
it will not move
if i go back to the position page the absolute is now zero on both axis
at this stage myself and the machine is now very confused

[mactec54]

Hi CMK1

Have you just tryed a tool change T1 M06 you may need the M06 on the next line I would not use a G28 the next thing I guess is to give Fanuc a call I know this is a pain but sometimes you have to do it

What about in auto mode to run a small program will it do it

[CMK1]

Hi CMK1

Have you just tryed a tool change T1 M06 you may need the M06 on the next line I would not use a G28 the next thing I guess is to give Fanuc a call I know this is a pain but sometimes you have to do it

What about in auto mode to run a small program will it do it

Have tried that
It needs to be in position before you give it a M6
i can manualy take it to position (Get atc ready led lit)give it a M6 it works fine.
it just wont work with G28 like it had done.

[stevo1]

The G28 to move to tool change position is fine. Being off 5mm is going to just be a parameter adjustment. Many machines that I have set up or seen set up use the G28Z0 to get to tool change position.

Being 5mm off can mean a few things. Your home position probably had to be changed for whatever reason. Typically most machines the home position is the tool change position. In the case that it is not then a G30 for 2nd, 3rd, or 4th reference position is used. Does your machine run a macro for the tool change?

You stated that the programmer said that this operated fine before so my guess would be to look at your parameter manual and find the parameter for 1st reference position and verify that it is set properly. If you are running a macro look to see if the macro has a hard coded number in there that might shift the Z for the tool change. Or see if the program uses a G30 and if so then you will have to adjust the reference position being used.

Did you try anything that I posted above in post#7? How does the machine run a program vs. MDI?

Stevo

[venomgrrrl]

re: Work offset, Im not shure if this will help you at all, but my m/c (is an ancient shizoka) and wasnt actually programed to use G52 work offsets (they where a feature that was actually sold!!). When in this position i suggest using a G92. The Workshift coordinate system. Balsicly i home m/c, zero everything, touch off my datum, and the position read there is what i put into my G92.

G00 G17 G20 G40 G80 G90
G91 G28 Z0.
G28 X0. Y0.
G92 X8.793 Y2.6235 Z0.

The X8.793 Y2.6235 are the coords read at my datum (for that particular piece)

Also when i home my m/c after touch off my abs, will zero itself, so it is important to write down position prior to homing.
then I manually touch off z axis for each tool.

Dont know if this helps at all, but i never would have figured it out without cnc zone.

[gbowne1]

G codes, G codes, G codes.. well I have a 6M-B and what venom posted is what I use in MDI. I use MasterCAM.. owned it since an early 9.0 version. Though my 6M-B was kind of home brew since it was pulled from a scrapped machine.

It would be lovely to have a G code reference for FANUC's on this section. I have one from a old textbook.. but it does not have many that are machine specific. Anyone care to toss one up here as a PDF or something?

Greg

[rapid]

sounds like may be a manual/absolute switch inside control panel that is off.
usually if handle loses position this is the case but depends on machine.

[CMK1]

Thanks Rapid
We got that problem sorted you were right there was a manual absolute switch that was causing the problem.