Fanuc 0-2000M motor ??

[jevs]

Does anyone know any specs on these motors like what the voltage/amperage requirements are? I am trying to see what drivers I could use if I decide to do away with the fanuc drivers. The motor plate says the following:
Fujitsu Fanuc LTD
Fanuc DC Motor
Type 0-2000M
No. D-771719
Date 77 10 (this is october 1977)
Permanent Magnet DC Servo Motor

[Al_The_Man]

Most of the earlier Fanuc DC motors resembled Gettys motors, they may have even been Gettys or knock off's. These were rated around 200vdc. if you post a Picture of one I may be able to identify it. They will for sure have a tach, but also you should confirm the feedback device, encoder or resolver, if you remove the rear cover, the resolver is usually driven from something like a 10:1 gear ratio due to the fact they were low resolution, an encoder would be mounted on the end of the motor shaft direct.
Al

[jevs]

Here is a couple pictures. One is of the encoder with the can cover off the end of the motor and the other is a small picture of the motor. From everything I researched the number on the plate comes back as a 2000 pulse encoder. It is also 1:1 direct driven. What drivers out there would be the least expensive for these motors? I am still debating on Mach2 or Camsoft I don't know enough to make the decision. Mach2 would be much cheeper though. I just don't know if it can do my tool changer, and I guess mach 2 is an open loop system. I wonder how well this would work verses closed loop with the camsoft/galil stuff.

[Al_The_Man]

I would guess these are around 20 ~ 25 ft/lb stall torque, There is a series of test that can be done to determine most of the characteristics of an unknown motor.
For example, this motor would be around 3000rpm tops at probabally 200vdc.
If you could drive the motor by another means at say 2500rpm and measure the generated voltage, this would approximate the maximum operating voltage.
The way I have used to obtain the Kt = Torque/Amp, is to obtain a nut larger enough to just slip along the motor shaft and pin the nut by means of a set screw into the keyway, I then use a torque wrench on the nut set the torque wrench to stall the shaft when a low DC voltage ( say from a auto. battery) is fed to the motor, you may have to insert a low ohm, high wattage resistor in series to limit the current, measure the current and voltage at the armature with the rotor locked this and this way you can arrive at the Torque/Amp (Kt).
There are other features that can be calculated, such as rotor inertia derived from the mass of the rotor, but in your case the motors are already sized, so some statistics are not necessary to calculate. The encoders can be used on any system that accepts that kind of resolution and will input the counts at the frequency you will be running at.
The Mach2 software is obviously the cheaper way to go, but the Camsoft, Acroloop and Delta-Tau motion systems equate to the commercial systems, many of which have gone over to the PC based systems. All of the three I mentioned have extensive built PLC control for functions such as Tool changers etc.
Other things to consider, if you also want analogue (speed) control of the existing spindle motor controller, plus hand-wheel option, an extra axis is required, (on a 3 axis mill the 4th axis output would control the spindle and the encoder input would be applied to the hand-wheel), unless you want to use the rigid tapping or constant surface feed options that the above mentioned cards can implement, then you would have to use the encoder input for spindle speed or spec. in 5 axis card.
Al

[HillBilly]

I believe the Fanuc system you have the motors do not have a tachometer. The controller had a F to V converter that produced a tachometer signal from the encoder that was send to the velocity drives along with the +/-10V command. So to use the original drives with +/-10V command you must add a tachometer or F to V converter. Just something else to consider.

Darek

[Al_The_Man]

I gather Jevs was going to do away with the current drives because of the 3 phase issue? With modern drives that will operate in the torque mode, (most do) you can do away with the tachometer now on DC motors.
Al

[jevs]

I talked to a place that repairs servo motors. They say that these motors are 63 Volt. They said Fanuc didn't use any motors in the 200V range.