Spindle motor problem, Mori SL-4

[jhoanrojas]

Hello everybody.

Last weeks the spindle motor of a Mori seikir SL4 has been failing. When It rotates manually, and then I push stop button, It starts to rotate clockwise inmediatly. During this fail I can make rotate in any direction, but I can't stop it. When I run any program this movement happens too after "M5" , so, no program can't continue while the motor still rotating.

I must wait a lot of minutes after the machine continues working normally.

I read the manuals and I can't find a solution. I really don't know if it could be a problem with the mainboard or the spindle velocity control unit.

I hope you can help me.

Thanks

[underthetire]

Since they built sl4s from late 70s to mid 80s, really helps to know what control, what spindle drive etc..

My guess it's a fuji drive and motor.

[jhoanrojas]

Oops! Its a fanuc 6T controller (a20b-0007-0010) and Fuji electric Drive (FSD-22DN)

[jhoanrojas]

Good day everybody.

This days my cnc lathe goes crazy. The operator told me that the machine run a program and when turret arrived to the zero position to change the tool to other position the program stopped, and the spindle continued rotating clockwise. Then I tryed to stop it turning off the control panel, but this still rotating.

After one hour the machine continued working normally.

I checked gain voltages. Teh where ok. So i will try to check spindle drive.

If someone has any idea, please tell me!

Many thanks

[underthetire]

Check the tach signal off the motor. Bad tach can cause a runaway. It might actually be a toothed sensor, but either way feedback signal needs to be checked.