FANUC 18M -problem with stopping x, y and z axes.

[nitroot]

Hi all,

I bought a machine QUASER MK60IIH with system FANUC 18-MC.
I have a problem with stopping x, y and z axes.
When I running one of the three axis in JOG, HANDLE or MEM mode happens delay stopping of all three axes. When release the button in JOG mode, or stop handwheel in HANDLE axis slowly stopped after a few millimeters. The same happens when run the program.
I noticed that the position on the screen immediately stop after the release button or a handwheel axis continues to slow down a few more millimeters.
At the C axis, this problem does not happen, that works without errors
All three axes have fanuc encoder, and Linear encoders for position control.
Does someone can help me where to start with solving this problem.
I tried with certain parameters for the acceleration / deceleration, but nothing has changed.
I added the parameters that are currently in the machine, if someone can conclude something from them.
and here is the original parameters that I received on a floppy disk with the machine.
Some of the parameters in the machine that are different from the original parameters I tried to change but nothing has changed.

[MMMMM]

This does sound like something with the Accel/Decel parameters.

My first question is - when did this start to happen? What has changed recently to make the machine behave incorrect? Did you purchase it this way? Are you getting any alarms?

Make sure that you power off the machine for any of these parameters to take effect. They need to load their values on boot-up (start-up).

I would restore the parameters back to original, cycle power and test before investigating other root causes.

[nitroot]

Hi M,

The machine is behaving like this since I bought it.
Nothing is changed in the meantime.
I found a about ten parameters that are different from the original, all related to motor and encoder.
I tried to put the parameters that are on disk, but then shakes the whole machine, probably the motors. I assume that servo settings do not match.
When I typed the old parameters, machine is behave normally, except that error when stopped all three axes.
The problem is that none of the pieces does not have the same dimensions.
The radius of the pieces is too bad.
I also suspect that something is wrong with the Accel / Decel parameters.
I do not believe that a mechanical problem, because it manifests exactly the same on all three axes.
The machine does not report any alarms.

[MMMMM]

If you bought this new, I'd be all over QUASER to fix it - CORRECTLY.
Otherwise, you're probably looking at having Fanuc come in to tune your drives. Or, someone with proper knowledge / tools.

[nitroot]

The machine is not new, produced in 1998.
Fanuc service does not exist in Serbia.
The machine was bought at auction in Sweden, so I have no information about how she worked before.

[KCRefugee]

I would guess that the problem is either a decel parameter needs to be adjusted, unit is faulting and coasting to a stop, limits are too loose that define position or mechanical wear at the coupling... hope this helps.