We bought a second hand GeFong GNP1712-D ( 1995) . Fanuc OT .
Everything was fine until I had to index the spindle for milling .
The machine have a 15 Deg index system .
On the back of the spindle I have one sensor who read 2 wheels . 1 got many teeth , the other have 1 slot only .
When I first used the M81 code ( Spindle Index) , I was using a program which worked fine previously .
The previous owner said that he never had issue with this .
Then I tried in MDI .
After M3 S1000 , I enter M81 . The spindle first slow down , stop and then make one more lap slower to find its Zero position . I can see C Axis values change at this moment , until the spindle stops and the monitor shows C 0.00 .
The spindle always stop when the sensor face the slot . then it stucks for 7 minutes until an alarm 1024 SP. INDEX appears .
I checked the sensors on the indexing pin piston
I checked the relays .
I checked the solenoid coil ( 1 thing is weird , when I activate manually the valve while machine is stucked , there is an alarm 08 on the spindle amplifier , if I release : no more ...)
I aligned the slotted wheel for the spindle to stop at a position that the indexing pin is perfectly centered
I adjusted the sensor to be 0.1 mm from the knurled ring (as required by MURATA datasheet) .
I tried to change slightly the parameters 6577 , 6531 : the spindle always stop at the same position …
When I look at the ladder , it seems that the “ ORARA” signal is missing . I guess that my C axis is not tuned with the position of the slotted ring … Correct ?
Can someone explain how this M code works and how to adjust this .
Thanks Everyone for you help ...
It was the timers values in the Diagnostic , who was wrong ...
Thanks again ...