Servo Drive and Motor Compatabilty

I have bought some used rotary tables to be used as the 4th and 5th axis on a Mori Seiki MVJR CNC with Yaskawa Servo Drives.

The main difference I see so far is that (If I understand correctly) the drives output -200 to +200 volts DC (I am not sure about this) and the servo motor is rated for 110 volts (140 max) DC.

I am wondering if the pots on the servo drive can be adjusted to make the voltage compatible or if I need to buy compatible servo motors.
Is there anything else that determines compatabilty?

The machine has these Yaskawa servo drives:

SV4 (4th axis) CPCR-MR0808KAW (DC dual 800watt drive)
SV5 (5th axis) CPCR-MR055K2 (DC 500watt drive for "Hi Cup" UGHMED-**GG servos)

www.yaskawa.com/site/dmservo.nsf/link2/T...ile/TSE-C717-13E.pdf
www.yaskawa.com/site/dmservo.nsf/link2/T...ile/TSE-C717-12G.pdf

The servo motor that is on the rotary table is a Servo Dynamics

Type: MTS30R4-42
No: W04085
The plate on the motor says:

Voltage 135
A 52

The spec sheet on the Servo Dynamics web page says the following:
www.servodynamics.com/MTSMOTORSPECS2013.pdf

Ke V/Krpm 42
Kt in/lb/A = 3.5
Max. Voltage = Volts 140
Con.Stall Current = Amps 9.4
Peak Current Amps = 45.9
Max. Speed rpm 300 = 0
Tachometer V/Kr mp = 7
Resistance Ohms = 1.15
Inductance mH = 2.4
Rated Speed rpm = 2500
Rated Volts Volts = 110
Rated Current Amps = 5.6

Looks like the MR0808 drive would work except for the maximum voltage may be a strain on the motors (and you would have to be careful about limiting the maximum motor RPM since the drive would cheerfully run the motor at 5000 RPM! ) An output inductor could be used to keep the peak motor voltage at a reasonable level (say 5 mH 30A)

The smaller MR055 drive has a max 85V output so should work directly but will not get to the full 2500 RPM and has a somewhat smaller peak current rating (20 A vs 24A for the MR808)

Neither drive can deliver the 45A peak current that the motor can support

PCW wrote:

An output inductor could be used to keep the peak motor voltage at a reasonable level (say 5 mH 30A)

That is fantastic news!
Can you direct me towards a suitable "output inductor" I had never heard of one before now., I have been searching Google to get asn understanding but have not made any useable progress so far.

PCW wrote:

Neither drive can deliver the 45A peak current that the motor can support

Does that seem like a problem or are you just saying it will not perform to the potential of the motor?
This is for a lightweight cutting application (cylinderhead porting) but moving the fixture (about 300 lbs)

The X Y and Z drives are the same as the 800w drive.

Thanks so much for your help. I was ready to buy new servos.

Looking at the motor specs (2.4 mH) and the cost of big inductors, the external inductor can be chosen to have the same the same inductance as the motor to reduce the PWM voltage the motor sees by 1/2, so 2.5 mH will do. Motor inductors were often used for DC drives in the past to protect the motor from excessive ripple current and to protect the drive in the event of armature shorts.

Here is a 30A one:
www.newark.com/hammond/195e30/inductor-c...2-5mh-smd/dp/94B9905

And a 20A version:
www.newark.com/hammond/195e20/dc-reactor...mh-20a-15/dp/52F9520

Which may be OK, There are undoubtedly cheaper sources.

Not having 45A peak output current mean the peak current will be limited to the drives 24A which works out to 84 inch lbs (1008 in oz) at the motor shaft.

Thanks for the help!

I opened the 2nd rotary table and found that it has a different type of servo motor.
It is a Minertia Motor UGJMED-60M A25F.

I am confused by the docs and can't figure out if it is compatible or not.

I double checked the servo drives to make sure the wiring diagram matches the parts and found a difference.

The wiring diagram for the 5th says the servo drive is CPCR-MR055 K2
But the label on the frame holding the board says CPCR-MR055K (the number 2 after the K is not there)

The data in the wiring diagram for the 4th seems to match the labels on the frame for the drive

There are some other #s on the boards, but I can't figure out the mean anything.



I can't see how the servo ID match this from the Yaskawa docs in regards to K and KAW, I was expecting to see some number there.

Here is the Yaskawa doc.
I am wondering if these motors are what I should use or if I should try to find the matching Yaskawa motors (assuming I can figure out what those are.)

I found both the recommended motor and the motor I have in the same table.
The rotary table I have has a UGJMED-60M Minertia motor..
The Yaskawa docs seem to call for a UGHMED-06GG Hi cup motor.

Looking at the tables the biggest difference to my naive electronics eye is the mH.
I looked it up and the unit is inductance (I am working on understanding what that is unit means)

My gut is telling me to just find the correct servo motors on eBay, I think I can find them for about $900 each.
That seems like the safest and most productive course to take unless someone that understands the situation better tells me that is a mistake.

Andypugh,

I am not understanding what you mean by: "That sounds like a way to potentially waste $900 to me..... "

Are you saying that one of the pairs of drives and motors are (or could be made compatible) or both?

It would be great if it would be possible to use either or both of the servo motors.

If I were to try to use what I have, I suppose that the following combinations would be the best:

4th Axis
Servo Drive:
CPCR-MR0808KAW (DC 800watt drive for "Hi Cup" UGHMED-**GG servos)

Servo Motor:
UGJMED-60M Minertia motor

This combination is new, posted after PCW explained about the output inductor.
Maybe that output inductor idea could be used to make this pair compatible.
I was looking at the pdfs that PCW linked, it lists many models and I have not made enough progress in my understanding of mH to know how to choose the correct one yet. Any guidance on that would be appreciated.
I don't understand how PCW figured out the servo drive voltage, I don't find that in the Yaskawa docs.
Does the output inductor work something like a resistor and reduce voltage?
(So far I only have a basic understanding of electricity AC/DC, Volts, Amps, Ohms, after that I need to learn)

5th Axis
Servo Drive:
CPCR-MR055K (DC 500watt drive for "Hi Cup" UGHMED-**GG servos)

Servo Motor:
Servo Dynamics
Type: MTS30R4-42
No: W04085

If I understand correctly, this pair could work OK but I don't understand how close to optimal the combination is.