Need Help!- Fanuc 6 M Alarm 401 and 420 Y Axis

[CBMach]

Hello
I have Kitamura my center 2 with fanuc 6 m
when strat up. it alarm 401 and 420 Y axis
( Sometime can start up for few miniute ) then go alarm as I said.
I have clean Brush, Check Drive By Swap X and Y.
Bolt drive is seem OK
Where to Check other?
Someone can help will be appreciated.

Thanks

CB

[GPena]

Alarm 401 can be caused by alarm 420, alarm 420 is a position deviation exsessive alarm in the Y axis. If all connections are OK and you already swap the dives and checked the motor, swap the motors with encoder if possible and test.

Good luck.

GP.

[CBMach]

Hi
Yes I aslo swap the motor + Endcoder between X and Y axis
The Error come to X axis.
I have not check all cable yet. But I have open the plug case. Look OK.
( Not measure Ohm yet , for case wire is broken in side )
I think cable may be OK.( becuase sometime can start up for few minute. )
Any other Suggestion?

Thank you in advance

CB

[GPena]

If you swapped the motors and encoders and the problem goes with the motor, then the problem in in the motor or encoder.

I suggest that you swap only the encoders now, if the problem goes with the encoder then the encoder is bad, if the probem stays in the motor then the motor is bad.

Good luck.

GP.

[CBMach]

It take long time for me to test that
But I found too many wire to remove to test .
I found new symptom.
When turn on the machine normally. It quite offen alarm 420
Or if it can get ready. May only few minute then Alarm 420.
Today I Turn on by Press " P' and " CAN ' botton.
It seem machine always get ready like normal
and can Run Whole day.
I belived tomorow If I turn on machine normally.
It will Alarm 420.
So For this sympton.
May someone can help me to solve real problem.

Thank you in advance

CBmach

[cnc-it]

Hi,
If you have not checked already make sure the velocity command from the CAV cable on the mother board is wired the same on each axis.
Also if you have an intermitent fault in another area of the machine ie. spindle drive it can sometimes cause the servos to jump on switch on causing your alarms 401 and 420 but actually the fault may not be sevo related at all.

John.

[hrh]

Try to fit a round "spacer" (made from thin gasket material) between the encoder and motor flange. This will reduce the pressure on the encoder shaft and disk. Do this for the "faulty" motor Y-axis.

You might have a problem with the master PCB as well. Swop the master PCB with a similar machine but take proper note of the short-pin settings.