Spindle Drive problem - need help ;)

[Dancy]

I have a Fanuc spindle drive on my Hitachi Seiki VK-45 VMC. The orientation board on the front of it is labeled A20B-0008-0030/08C and the main board is a A20B-1001-0120. I think that would make it an A06B-6055-H112. Not sure. There is a single magnetic sensor on the spindle with one magnet.

The problems I am having I believe are related to the orientation board (guess!). My machine is having problems with the M19 command. If the spindle is running in high range, it will slow to a stop and then creep at about 1 rpm forever. If the spindle is in low range it will orient correctly but may begin to creep or oscillate after a bit. I also can not perform a peck drill cycle G83. The Z axis moves to position, spindle to rpm and then just sits there and the program will not advance and the drilling does not start.

I am hoping this is just an adjustment but at this point I have no documentation on the drive at all so it is just a funny looking PCB with buttons and knobs I don’t dare touch. I have been in the service industry field for years I am comfortable working on something like this if possible and have all the tools such as scopes, meters and the like. Can anyone help me tune this or repair it if needed?

Dan
Way out in Summerville

[Eurisko]

Dan,

I may be way off base, but could these symptoms be caused by a faulty tool clamp switch? I have a nagging feeling that this might be the case.

[thebodger@roger]

maybe just an adjustment. i have looked at many of these over the years. first off, there is a bunch of potentiometers on the orientation card. mark the present settings with a sharp point marker, so that you can return to the present settings if needed. half the settings are for low gear, the other for high gear. what each potentiometer does is labeled on the PCB next to the pot. i must tell you that adjusting one pot will affect the others a bit. you don't need to play with the position adjustment. just tweak the pots for sensitivity and in position.

[Dancy]

That helps! I will give it a try.

Dan

TY!