Fanuc AC Spindle and DC servos with geckos

I am rebuilding a DAH LIH MC3 it has a 5hp AC motor and DC servos with resolvers for the xyz axis. I will upgrade the servos to newer servos with encoders and drive them with geckos. This part is easy and I can make that work with linuxcnc. I am struggling to find information on how to interface a fanuc AC spindle with linuxcnc and their drives. Are they step and direction like a gecko? Im thinking not. Or perhaps some serial communication? Is this a simple setup having DC xyz and Fanuc AC spindle or am I getting into a mess? Im sure the answer is simple but Im struggling to find the information I need. Help is much appreciated. Thank you.

I'm no expert but AFAIR fanuc spindle motors are really just big servos.

They can use one of a number of feedback methods.

John E of Pico systems fame:
jelinux.pico-systems.com/motion.html

Probably knows the most about using fanuc motors, I'm sure he will pipe up soon.

A pic of the motor and some name plate numbers probably would help.

Chris M

sgsracing wrote:

I am rebuilding a DAH LIH MC3 it has a 5hp AC motor and DC servos with resolvers for the xyz axis. I will upgrade the servos to newer servos with encoders and drive them with geckos.

Newer servos != better servos. I recommend to use the existing servos as they are already engineered to your machine and only place a new encoder on them. This will save you a large amount of money and will provide a better machine (and less work).

I actually do not have an AC Servo picked out yet. I Just couldnt find any control or feed back info on any Fanuc products which seemed odd. Im obviously looking in the wrong spots. I just could not tell if they had step and direction type drives or something different. and could I get linuxcnc to control this while still using step and direction servos for XYZ.. (im sure it can, just having difficulty finding that bit of info written down!) Im open to suggestions. What I am ultimately looking to do is use the DC servos for linear control and I want an AC spindle servo so I can thread with my spindle. Anymore help is greatly appreciated.

Maybe I can give you some help. Can you post the servos information? Ratings?

emcPT,

I dont have ANY servos bought or decided upon yet. I know that I will be using NEMA 42 Brushed DC servos run form a gecko for my XYZ and this is no problem. I can get that to work easy-breezy. It's the AC Servo Spindle that I cant find any technical information on. I want to use a Fanuc AC servo of some description (5HP) I am having a difficult time finding out how to control a Fanuc AC Spindle with linuxcnc.

AFAIK Fanuc does not use step/dir in any of their servo or spindle drives
Older spindle drives are analog, then they went to fiber Optic

My comment was in respect to the servos for the linear movement. You can maybe reuse them (still my opinion rather than buying new). Please post the ratings of the servos.
Regarding the spindle, also without information, it is hard to help. Check the plate on the motor, check the drive where the spindle is currently connected, provide all the info that you can.

" AFAIK Fanuc does not use step/dir in any of their servo or spindle drives
Older spindle drives are analog, then they went to fiber Optic "


This is the info Im looking for. How did it communicate from the PC to the Drive, and how or where,do you configure it in Linuxcnc. Anything I have worked on in the past was Spindle on/off. I cant find anything on the web and I need to spec a spindle. Keep in mind I have not picked a spindle yet and my options are open. Thank you!

Analog 0-10V + CW or CCW is easy.
All commercial VFDs will accept this.