Makino A55 and A55e BTS (broken tool sensor) -problems

Hi all,

We have several Makino A55 and A55e machines in our factory. All with Fanuc Pro3 controll. We've been having a lot of trouble lately with those broken tool sensors. All the BTS`s, what we have, are ATC-side models manufactured by NSK. They have a motor directly at the end of the ball screw and a separate, large circuit board inside the electrical cabinet of the machine.

All programming and adjustment procedures are done with a separate hand remote control, which is connected to the cable of the BTS. Fortunately, we have this remote control.

We also have several different instructions with quite a lot of differences between them. I'm not sure which of them I can trust anymore.

The main problem is that the BTS loses the measurement in some areas. Currently between 200-240mm. We have tried to adjust the BTS according to the instructions. It may work for a few hours, but then it may stop measuring and stop. There is no alarm.
We have replaced another used BTS unit and also the circuit board. Still same problems. Could the fault be in the programming of our measurement points, in the reference point of the BTS or possibly in a faulty circuit board?