[senna95]

Hi All,
Have an ancient Nakamura twin spindle TW-30 with a Fanuc OT control.
Left side of machine has not worked in years.
We have been using the right side all along.
Today the control would not execute anything in AUTO mode. Operator was running machine and noticed problem upon trying to cycle his next part.
The control will not execute any MDI commands either.
Powered off machine completely and can zero machine out, index turret and turn spindle on manually. But no auto operation.
The machine is in a ready state. There aren't any error codes on screen nor do any of the boards have any idiot lights on.
The fact I don't have the manufacturer manual, I cant really look at the ladder to determine what the heck is going on.

Any suggestions?

[guhl]

if system 0TB you can't look at ladder, but there is a way to decompile eeproms and check what's on
is system 0TC or TD you are able to display the ladder by setting to 1 parameter 60 bit 2
also check diagnostic parameter 120 bit 1 (start lock signal), 1 in this parameter is abnormal condition

[senna95]

I can see the ladder.
Diagnostic number 120 bit 1 is zero

[guhl]

what is your CNC?

[senna95]

Its a Nakamura TW-30 with a Fanuc OTc

[guhl]

you have to check ladder lines with:
G121.5 (feed hold)
G122.0 (MDI)
G120.2 (cycle start lamp)
G121.7 (external reset)
may be this is not enough
the best way is to see ladder

[senna95]

Will do.
Thanks

[zavateandu]

I know what is your problem
it happens to me a lot on nakamura machines
please check the sensor for spindle clamp that will not give you any alarm is the sensor is not on after clamp the part.

[firecat69]

I agree with zavateandu, there are proximity sensors at the left end of machine (spindle tube) that tell the machine whether or not the spindle is in clamp or unclamp position. Replaced one last year on our Nakamura.