Avid and MACH4 G54 stuff

I have a lot of questions on running my Mach4, I run my programs using G54, when I home my machine and zero XYZ, it wipes out my G54, is that normal?. Also, I ran a part changing my Z depth to one inch higher than the actual setting to prove my program out, and when I changed my offset back to the actual Z depth and homed everything, it still ran an inch higher than the part was. I still can’t get it to cut. Should I use G55 or something maybe to run my programs?. Thank you and any help would be great.

Homing the machine is the same as zeroing the machine. The Zero X/Y/Z buttons are for zeroing G54 (or whichever offset is selected). Only use the Zero X/Y/Z buttons to set the work offsets according to the current machine location.

Unexpected vertical offsets are usually because of inconsistent Z zero locations between software and CNC. For example, you’re using the touchplate at the top of the part when your CAD/CAM setup has the zero located at the bottom of the part. (See also Avid’s troubleshooting page.)

Thank you very much for the help.

That is very odd. I can leave my work offset defined for weeks on end if I am running the same project for that period. Every day I start the machine from a cold boot and home before beginning.

As big as my machine is and as many tools are on my carousel I can set many, many work offsets. Generally this gives me the ability to run projects in parallel from the same stock. And I do this for multiple days on end once the setup is defined. My ERP system will spit out these production g-code files by combining the g-code from separate files and organize them by tool. So all 1/4" compression bit cuts are done for each file based in a different work offset for example.

Maybe I am not understanding :grimacing: I am a bit think sometimes :roll_eyes:

PS. I and my operators also re-home before every execution as well.

This is killing me, the z zero is set off the locating surface, it is the same G54 Z-6.0880 and has ran the same jobs for 5 years. For some reason the Y changed by around .040 thou and so I added .040 to my Y value in G54 and set my Z to -5.0880 to run the cutter an inch above the part so I could watch the cutter and make sure my Y shift was the correct direction and even after I set my Z back to -6.0880 it runs all programs an inch above the part. This is so crazy. My touch plate is accurate, I even manually set the tool and it matched the touch plate Z. I even put the Y offset back in case that confused the controller ha ha. I would hate to lie to the machine and set it at -7.0880, that could leave a mark at some point in time.

@poolrod This is the way it’s supposed to work. If you set a G54, G55, G56 offset when you power off or re home those offsets should stick.

This would mean that you could power off your machine, power it on, home and run the same job and maintain offsets for X Y and Z (provided you didn’t change your bit)

Can you walk me through your exact homing procedure when you power up your machine?

Any chance the homing sensor setup was bumped?

So the tool is the same, it has the same stick-out, the Z was homed, the part location is the same, the offset is the same, the programs are the same, and it’s now an inch above where it used to be? That is a puzzle.

Are there any non-zero values in the tool table?
Are there any other new symptoms?
Did anything on the Z axis change position? Homing sensor, spindle? Does the Z axis look normal during homing?
When you jog the Z position as high as it can go, does the machine Z position read zero? When you jog it back down to -6.0880, is it at the Z zero for the part? If you mark both positions and measure with a ruler, is the difference consistent with 6.088"?

You could try restoring the Mach 4 profile, which sometimes helps with “generally inexplicable changes to Mach4 settings”.

Hi Eric, I turn on the machine , turn on the computer, run Warp 9 software, home xyz all at the same time, load my program, any program that ran fine. My cutter is already preset at 1.7 stickout and has ran several perfect parts. I wanted to check my touchplate out for errors but it was on the money. In MDI I punched in G00 Z2.0 F500 and it went 2 inches up from where it was. I have no Z value in the tool offset, just G54 and it runs 1inch higher than it should with any (working) program. My number is 425-287-3884 Rod Weflen

How are you homing XYZ? Specifically which buttons are you using?

HOME XYZ AXES under machine position

I just ran the backup and same result, Z is high.

And you’re not pressing Zero X Y or Z? If you are than that’s the culprit.

What I have noticed Mach does do is switch BACK to G54 after freshly powering it up. Maybe that’s what’s throwing you off? Perhaps you have set an offset on G55, 56 etc and it’s swapping you back to G54 and you’re not realizing it?

Ok, so I reprogrammed one of the operations and used the touchplate on the top of the block and front left corner. It gave my new values in XYZ as it should. It ran fine but when it ended, it replaced my XYZ offsets with the original. Is that normal or is something corrupt?. That could cause serious damage to a workpiece if it wasn’t caught.

So from one Y shift in G54, the Z changed from -6.088 to -7.5472 to cut the parts correctly.

The touch plate utility’s purpose is to help you set XY and Z offsets so if you ran that utility it would overwrite whatever your current work offset is.

I used the touch plate and then added -1.226 in Z to get it to cut the part. The program Z was -1.226 from the locating surface in Mastercam so I added that to the negative value. All the programs for months ran perfect with the touch plate original number. This is confusing to me.

Do you have any tool lengths set? You can look up the tool table in Mach by going to Tool Change tab.

All tool numbers should be zero. If they’re non zero that is likely your Z height problem.

There is no values in the tool offset, it would make sense if there was a value of -1.226 there but no such luck. Anyway I got it working so thank you for the help.

You’re welcome, glad you got things going.

Thank you, you people are all great help.