Random NC File Changes

[Jim at Gentex]

Here's one for the record books.

Weekend programmer wrote a program to run a prototype part on our 5-axis Haas.
He submits it for first article testing and, the part looks great and is 100% in tolerance.

Monday morning, Engineering asks the day shift operator to run 5 more of the same part.
He runs the first one, and a hole that is profile milled is now oval instead of round.

I check the NC program in the control against the backup copy on a flash drive and find a random Y value right in the middle of that hole profiling op that was off by more than 0.1"

Programmer insists he did ZERO editing of the file, and it should match the file on the flash drive.

So the bottom line is that he ran a good part on Saturday, and the day shift operator ran a scrap part on Monday running the SAME NC program. 

Is it possible, or has anyone ever heard of random values changing in a program stored in memory in the control?

I don't know what to make of this...

[JParis]

Did the program get sent out and back into the control?

I've interference in RS-232 cabling do some odd stuff like that before.

[gcode]

day shift operator edited the file

[Flycut]

How do you transfer files?
I've seen strange things happen when a USB is removed at times.
I make sure my machines are stopped and in handle mode before removing the USB.

[CNCAppsJames]

Day Shift screwed the pooch.

I've never seen a program randomly change unless acted upon by a file transfer... even on a FADAL.

[Jim at Gentex]

Thanks for the replies.

We only transfer files to that machine via jump drive through the USB port.

I keep coming back to the fact that weekend guy loaded that program into the control and made a good part with no errors.  The error occurred after the first part was made, and afaik the program only loaded into the control once, and was not transferred again. I guess the only other possibility is that he changed it after the fact, but that doesn't make any sense either.

Day shift guy and I have worked together for around six years, and he has NEVER done anything like that.
He is a good machinist, and a solid CNC operator.

Weekend guy has only been here a little over a year, and truth be told, he and day shift guy don't really get along all that well.

Since it is obvious that ONE of them changed it, I'm beginning to think maybe this is just a pissing contest between the two of them.

Either way I don't like it because somebody DELIBERATELY scrapped a part, but I doubt I will ever know what really happened. 

[JParis]

Weekend guy has only been here a little over a year, and truth be told, he and day shift guy don't really get along all that well.

When you remove all other possibilites, the one that remains is almost certainly the reason...

[Jim at Gentex]

When you remove all other possibilites, th eone that remains is almost certainly the reason...

Yep.
As long as I can rule out the possibility that the error wasn't caused by something like a faulty memory chip in the control, I will rest much easier when I load a program into that machine.

Now that I am reasonably sure it was caused by human intervention, I will have a private chat with our department manager about the whole situation and let him deal with it. 

[Jeff]

Check the NC files in File Explorer and the date they were last edited, does it coincide with when the parts were ran initially?
This will only rule out changing it at the computer and not at the machine though.
Does the Haas save the last edit date by chance?

[Jim at Gentex]

Check the NC files in File Explorer and the date they were last edited, does it coincide with when the parts were ran initially?
This will only rule out changing it at the computer and not at the machine though.
Does the Haas save the last edit date by chance?

Thanks, Jeff.
I don't see any way to determine when it was edited in the control.
Besides, we already changed it back to the original value in the control, so that would be the last edit.
Unless there is an actual editing log somewhere in the control, that is a dead end.
If there is such a log, I would need a Haas guru to show me where it is.

The original date/time block from the post is there, and it is the same in the control copy as well as the flash drive copy, and the copy backed up to the network.
But that only gives me the original date/time the NC file was generated.

I had a chat with my manager and he said he plans to speak to both individuals about this, so we'll see what happens.

[kccadcam]

Is it the Next Gen Control?
You can backup every keystroke.

https://www.haascnc.com/service/service-content/guide-procedures/ngc---backup-machine.html

System Data makes copies of these data files:
settings
offsets
macro variables
advanced tool management (ATM)
alarm history
key history <------------------------
linear screw compensation (LSC)
network configurations

You can do this thru the network also, does not have to be USB.

[Jim at Gentex]

Is it the Next Gen Control?
You can backup every keystroke.

https://www.haascnc.com/service/service-content/guide-procedures/ngc---backup-machine.html

System Data makes copies of these data files:
settings
offsets
macro variables
advanced tool management (ATM)
alarm history
key history <------------------------
linear screw compensation (LSC)
network configurations

You can do this thru the network also, does not have to be USB.

Thanks.
Unfortunately we do NOT have the next gen control.
I think the machine was purchased around 2014, so whatever the standard control was back then is what it has.

[kccadcam]

On the Haas Classic control, It's a little more involved, but it looks like you can do this.....

https://www.haascnc.com/service/troubleshooting-and-how-to/how-to/keystroke-and-alarm-history-analyzer.html

[Jim at Gentex]

10bucks says he's cock-blocking!
Got his 1st off okay, then his nemesis produces the scrap....

Yeah that's what I'm thinking may be the case, but no way of proving it thus far.

Thanks for the info kccadcam.

It looks to me like that keystroke logger app could possibly sort it out.
Wouldn't that app have had to already be installed prior to the day in question though?

Also, it looks like it logs all function key strokes, but not every single individual key stroke.
I would be looking for an edit function, but I would also need to show that the Y value in question was actually changed from Y0.aaa to Y0.bbb) during that edit. 

Not sure I can get that level of detail from this app.

[Matthew Hajicek]

I haven't seen a program get changed like that, but I have had the control lock up when removing the USB drive a few times.  Have to reboot to clear it.

I wouldn't rule out maleficence, but I wouldn't rule out a rare technical error either.  Jumping the gun and blaming one of the operators could come back to bite you if you're wrong.

If this were part of a pattern of behavior, that could be a different story.