[CNCturtle]

I have a 1987 Okuma mill with Fanuc 10M-A control. A friend jogged to the hard limit and tripped an alarm. It won't let me jog or use the handles to back off of the limit switch, the reset button doesn't seem to do anything, and I can't find anything useful in the manuals. I'm guessing the answer is simple but I just can't find it!

Any help would be much appreciated.

[fordav11]

normally there is a button that is pressed and held, then power off/on and move the machine with the handle in manual mode. if no OT-release button then you have to move the leadscrew by hand with power off.

if the end of the leadscrew is easily accessible and has a hex on it you can use that to wind it back (with power off)
or if not accessible you could remove the covers exposing the lead screw and wind it back by hand (again with power off).

or set the limit parameters so that the machine thinks it is still inside the limits. power off/on and there should be no alarm.
move machine with handle then set parameters back as they were.

[beege]

Sometimes if you put it in handwheel mode, hold down the "power on" button, and turn the handwheel, it will move off the offending switch. Try that, and if it doesn't work, try a different button the same way (reset?).

[Harmeet]

or if you have electrical manual
1)Just make the control on relay ON forcibly by giving supply to its coil by using a wire.
2) Or u can bypass the hardware over travel limit switch by using a wire...
then move the axis back in working limit and remove the wire..
as simple as that...

[Anders6612]

Maybe pressing "can" and "P" button att restart works?

[Al_The_Man]

CAN/P is for soft overtravel, There should be an override switch as mentioned, the other way is to remove a wire from the N.C. O.T. SW or drop the switch off if the axis cannot be moved with the Ball screw.
Al.

[CNCturtle]

Thank you for the suggestions. I held the "machine ready" button in and switched the machine on and it let me back right off the switch. Hooray! It seems that no soft limit was ever reached before hitting the hard limit and when I jog the other direction I hit the soft limit maybe 1-2" short of the switch. So it appears that my soft limits are biased. Can I change that bias by switching the machine off and rotating the ballscrew?
I have been a little worried about doing so because I don't want to change some factory calibration or something. I'm still pretty new to the parameters and this control in general. I haven't dared change anything yet :-)

Thanks again for the kind help!

[fordav11]

the soft limits are set with parameters. to change them you need to change X/Z stroke limit parameters. I dont have the 10-series parameter manual but if you have one you should be able to find them easily.