Need help: Fanuc 0M motors, 2000 ct encoders, & AMC drives.

[jimjovan]

Hello,

I am working on retrofitting an old Shizuoka AN-S mill with 6MB Fanuc controls. The mill has three Fanuc 0M servo motors (A06B-0613-B031 Fanuc 0M - 12A peak, 56V, 2000 rpm, 2000 count encoder). The peak torque at stall is 2.7 N/M with 12 amps.

I found the following from someone's previous post:

Fanuc DC Motor 0 (z axis)
Type: 0-2000M
Part Number A06B-0613-B031
Output Power: 0.4 KW (0.5 HP)
Rated Torque: 28 Kg-Cm
Max. Torque: 240 Kg-Cm
Max. Speed: 2000 Rpm
Rotor Inertia: 0.029 Kg-Cm-S 3
Back EMF Constant: 25 V/K RPM
Torque Constant: 2.44 Kg-Cm/Amp
Mechanical Time Constant: 25 mSec
Thermal Time Constant: 50 Min
Weight: 12 Kg

I am looking at driving these motors with Advanced Motion Controls amplifiers. Would amplifiers that supply 20 amps max. with 80 VDC max. work good or should I be looking at 25 amp units?

Will a 1.5 KVa power supply with around 65 VDC work OK with my machine or should I be looking at something in the 2.0 KVa range?

I am also hoping to reuse the Fanuc encoders. I found previous posts by Al_the_man that gave the wiring for these encoders, but I do not understand what the z/-z output lines are. Do these encoders have an index signal on the z lines? Am I correct in thinking these encoders are 500 line units with 2000 quad counts? The motors are direct drive to the 0.200 pitch lead screws. With 2000 counts, the resolution should be 0.0001. Is that correct?

I've attached a photo of the encoders. I think the two blue wires coming from the motors are the temperature sensors lines (OH1 & OH2).

The plan is to drive the AMC amps with a Galil DMC-1750 ISA card & Mach3. I found a new Pentium IV motherboard off ebay with a couple of ISA slots (not many computers have them anymore). Hopefully that piece of the puzzle will work OK.

All help is appreciated.

Jim

[Al_The_Man]

I would be inclined to use the AMC 30A20's minimum.
Also you can use their Brushless DC drives just as well for DC brushed, this is usefull if you ever lose a motor and wish to change to a DCBL.
1.5Kva should just about be OK considering the anticipated duty cycle, 2kva may be worth the extra.
The encoders are 2000 quadrature counts /rev so this gives a resolution of 8000/rev when used in quadrature x4, which Galil does, (quadrature refers to the basic pulse/rev).
0.000025" resolution.
Galil uses the Z 1/rev marker pulse for homing the machine, normally the Galil routine looks for the home L.S. first and then seeks the marker at creep speed to set reference.
Al.