Y-axis lock Kitamura Mycenter 1B Fanuc0M 1986

Dear sirs,
is anyone familiar with possible reasons for interlock (think it´s the right word) in Y-axis only? The error is intermittent, Y axis comes and goes from time to time and it can be seen in parameter 128 where it sets the Y-axis bit to 0 and sometimes back to 1 after some time, minutes to hours. No alarm, just puts it on hold if running a program and sometimes it continues after a while when it regains the signal or whatever it is. I do not have a ladder documentation and the ladder can´t be seen on the controller.

The above are things I just learned, through forums and friends, I had not previously checked any diagnosis parameters and I have not had to check a ladder diagram. I have had the machine since 2003 and only made base service work like new bearings and some axis microswitches.

I´m hoping it can be a "hard" component somewhere I didn´t think of and hopefully not for example motherboard or something else above my head. I have looked around the machine within the limits of my knowledge as well as had some better qualified help with no result so far.

I have been a spectator on cnczone forums for years and I think this is the time to bother you cleverer people with another problem!

My wife and I run a tiny family-workshop on the countryside in southern Sweden.

Regards,
Tobias

Perhaps consider motor cables and maybe servo drives. If your Y axis is using the same drive as is used with another axis, you can swap the two drives around to try to isolate the problem. If you have another identical machine, you can also borrow a drive from it. Is Y axis vertical or horizontal? In most scenarios, the vertical axis has a larger servo drive than the other two in a CNC mill. If that’s your Y axis, then you might be facing a set of drives who’s Y axis is bigger and swapping wouldn’t be possible unless you do have an identical drive in another machine.

On the other hand, If the Y axis IS the vertical axis, I would focus on motor cables as these cables would flex with the movement of Y, in that case, AND this machine is likely quite old given the control vintage.


Kind Regards,
John.

Hi John,
thank you for the idea. I might try this after all. The x-, and y-axis servos looks the same, both horizontal. The reason I haven't yet is that I got information from a specialist that there are no signals going from the servos that will make the controller lock the axis. Perhaps you guys out there know differently?

It's an old 1986 machine and I have started to look around for a replacement. This Kitamura is perfect as my backup machine except that it hasn't rigid tapping (That and that it's not working now....).

Regards,
Tobias