Weird Fanuc 31i Work Offset Issue

[Andrew.Bird]

We have several Fanuc Robodrills using 31i controllers that have an issue with the work offset measure function. The machines all run in inches, but when you measure something, it inputs the number into the work offset as metric. But what is even more weird is if you convert the number to inches, it isn't correct, it's obviously off several inches.

The only way we have found to get it to work is to go to the settings page where you turn on/off PWE and change the parameter for Input Unit to mm, then measure, then switch the parameter back to inches, which switches the work offsets to inches as well.

Not my picture, but this screen:

Adding to the weirdness, The Absolute and Relative position readouts are in inches, but the Machine readouts are in mm.

Anyone have any idea what is going on?

 

[MaxPrairie]

Did someone mess something up when calibrating the probes?

 

[Andrew.Bird]

We don't use a probe, we use a dial indicator to indicate a hole in our fixturing. There are no programs or macros running in the background, just the built-in measure feature in the Fanuc controller.

 

[MaxPrairie]

Sounds like I would be calling Fanuc and asking a tech. Did you just get these machines? Or have you had these machines for a while and the issue started? Did you buy the machines used and someone is messing with you?

 

[sakis]

Your looking for a parameter titled MCN. I believe it's around there 3000's.

 

[Vancbiker]

To get the machine position readout to be in inches, set parameter 3104 bit 0 to 1. Not sure if that will fix your offset setting issue though.

 

[Andrew.Bird]

To get the machine position readout to be in inches, set parameter 3104 bit 0 to 1. Not sure if that will fix your offset setting issue though.

That did it! Thanks!

 

[Vancbiker]

That did it! Thanks!

Fix the offset setting trouble too?

 

[sinha]

This has been my general observation that a machine should be used either in mm mode or in inch mode, exclusively, for both programming as well as offset setting. There are so many parameters involved that mixing the two may create problems. Even for the same control series, its different models (e.g., C and D) may behave differently in some cases.