MCG Server Controller for 4th axis

I have a small rotary table I'm trying to get working. It has an old MCG servo (Model
MCG 2234-M4903) attached to rotate the table. MCG has been out of business for a while, and there's not a ton of info out there about these motors.

According to the servo's label (see picture), it's 50 oz-in, 2 amps, and 3000 rpm. I think it probably takes 60V.My main goal is finding a suitable servo driver with good LinuxCNC compatibility.

I assume LinuxCNC works with servo drivers in a similar way to stepper drivers. I'm using a Mesa 7i96s for my interface board.The servo motor itself has an old DB-style connector with 15 pins (two missing) and a 4-pin DIN-style connector. I'll have to figure that part out later.If anyone has any info or tips, I'd appreciate it.Thanks. 

The dc servo motor you have is fine and can be used to operate with Linuxcnc. You need either an analog (+-10vdc) or digital (pul/dir) brushed dc servo drive. I use Copley Junus (analog drive) for digital drive Leadshine DC810 is a popular digital servo drive (I have no experience with these drives) both the Copley and the Leadshine require a dc servo power supply. I have seen on EBAY Advance Motion Control drives with built in dc power supply. Since your servo motor is low current and standard voltage you should be able to find what you need on EBAY.
In nut shell you need to match your current Mesa hardware with either analog or digital servo drive. Then start looking for the drive that match your servo motor.
Good luck Ben

Thanks for they reply. I bought this controller on ebay(picture). it was cheap, not totally sure it will work, but it was $25. I think right now the biggest problem is going to be figuring out the wiring on the motor, because it's not labeled or anything. I'll look into those controllers as well.

Also do you think 60v sounds right ? that seem high to me. 

This is a relabeled AMC analog servo amplifier. Probably quite similar to their BX25A20 model. If you look that up, you will see the OBVIOUS similarity. A number of companies sold AMC amps under their own label. This amp takes in analog -10 V to +10 V velocity command signals, and apparently generates a synthetic tach signal from the encoder A and B signals. You need a controller that provides an analog velocity command output. Pico Systems has their PPMC, and Mesa has suitable options, too. This is nothing like a step-direction drive system. An analog velocity command voltage is sent from the control, the servo amp delivers voltage to the proper motor windings to make the motor's speed match in proportion to the command, and the encoder provides position feedback to the control PC.
Jon

Like jmelson suggested. Look also at docs for BE25A20 or similar from AMC.
I'm guessing your motor is brushed with encoder? This drive should run brushed or brushless. Set the 60 deg phasing switch for brushed and use phase1 and 2 for the motor. (check doc 1st)
You need to confirm the voltage class of the drive and set the current limit dip switches and pot to match your motor. Continuous current and peak. 
Some things to look out for is the drive may not be isolated. AMC makes isolated and non isolated versions and I had trouble with noise on my machine. May or may not be an issue for your setup.
Also you will have to tune the drive 1st before hooking it up to linuxcnc. Ideally you'll need a function generator and scope to get it correct. If your motor is a good match, you may get lucky and can tune it close with the dip switches/gain pot and without the need of scope.
Linuxcnc's built in scope will reveal if your drive is not tuned correctly once hooked up to the machine.

Just so I'm following correctly with the servo amplifier I would still need a controller such as a DCS810?

The Leadshine DCS810 is a brush-motor servo drive, essentially similar to the MCG servo amp you already have. It ALSO needs a controller, which it is NOT.
What I THINK you are trying to do is create a standalone positioning control for the rotary table. Is that right? Or, do you want to integrate the rotary table into some other CNC system?
If you have some system that produces step/direction pulses, then you need a step to servo drive. Assuming the motor is indeed a brush motor, then the Gecko 320X is likely the best way to go.
Jon

The idea is to use it as a 4th Axis in a CNC mill. The machine already has closed loop stepper drives for x, y and z controlled via a Mesa 7i96s.

The servo motor is most likely brushed based on similar motors I've seen for sale.

So if I understand this correctly, wiring the MCG servo amp directly to the 7i96s control the motor wont work (I'm using the analog pins for the spindle currently). I need to have an intermediary device such as the Gecko 320X to convert the signals? or would it be easier to just get a DCS810 and use it directly with step/dir wiring to the 7i96 ? Or is it likely that this motor doesn't do step/ dir, only analog ?

Sorry I don;t have a ton of experience with servos.

spacestate1 wrote:

The idea is to use it as a 4th Axis in a CNC mill. The machine already has closed loop stepper drives for x, y and z controlled via a Mesa 7i96s.

So if I understand this correctly, wiring the MCG servo amp directly to the 7i96s control the motor wont work (I'm using the analog pins for the spindle currently).

I need to have an intermediary device such as the Gecko 320X to convert the signals? or would it be easier to just get a DCS810 and use it directly with step/dir wiring to the 7i96 ? Or is it likely that this motor doesn't do step/ dir, only analog ?
 

Yes, I am pretty sure you are right, the Mesa board probably will send step/direction to a motor drive, and the MCG drive wants analog.  But, a Gecko 320X will do what you want.  steps in -- brush motor out.
Jon