Select servo drive for mysterious servo motor

Hi all,

Why do I get these jobs! We have a customer who has imported a new multi axis stacking machine. The machine is minus wiring and controls but has servo motors fitted. There is limited to no information about these servos on the name plates.

This is my first servo job too by the way.

Is it possible to match up a third party servo drive, from say Omron to the limited details available? I have only had a quick look at it but we have rpm, torque, voltage, Hz & current. I imagine there is lots more detail the servo drive will require to get this to run smoothly. Can this be done? Or am I walking up a path to no where? If it's to hard I can try and push for the replacement of the motors, but that's a long shot and I would risk losing this job to a competitor.

Thanks, NP

HJTRBO said:

Hi all,

Why do I get these jobs! We have a customer who has imported a new multi axis stacking machine. The machine is minus wiring and controls but has servo motors fitted. There is limited to no information about these servos on the name plates.

This is my first servo job too by the way.

Is it possible to match up a third party servo drive, from say Omron to the limited details available? I have only had a quick look at it but we have rpm, torque, voltage, Hz & current. I imagine there is lots more detail the servo drive will require to get this to run smoothly. Can this be done? Or am I walking up a path to no where? If it's to hard I can try and push for the replacement of the motors, but that's a long shot and I would risk losing this job to a competitor.

Thanks, NP

Click to expand...

It's certainly possible, but you will need much more info regarding the servo motors; things like rotor inertia, winding inductance, encoder counts, connection diagrams, etc... That info should be available from the motor manufacturer, provided you have that info. You might also call your drive vendor of choice and see if they have info that might help; many drive manufacturers have info on competitors' motors for just this situation. Good luck, and good hunting.


SceneryDriver

You might want to let this one go... your competitor will face the same problems.

Virtually all servo vendors match their motors very closely with their drives. The drive needs to know quite a bit about the motor, especially the feedback device, in order to work correctly.

Were the vendor nameplates removed from the servomotors ? Are there part numbers anywhere at all ?

Without something to tell you what's inside the feedback devices you can't even really get started. You could guess at the voltage and guess at the wiring diagrams but if you have eight or ten wires you'll be at it for a while.

How on earth do you import a "new" machine with no controls ? It sounds like the owner may have very unrealistic ideas about how complicated machine control programming is, even for the people who designed the machine and understand its intended operation.

Thanks for the replies guys.

Yes I do need a lot more information. I had a quick look at some Lenze software I had lying around and there is a quite few boxes to fill out to create a custom motor profile! I'm confident I know what servo data I need now from the servo manufacturer. I will try to gather this information without spending to much time on it. (A quick email to the machine importer requesting this information should do it). If I can't get this information then my path is already written, they buy new servos from me or someone else can do it!

Ken, I beleive this guy brings odd machines in from time to time at an absoloute steal, and then locally sources the wiring and controls. It must work out more profitable for him I'm guessing??? He drives a much nicer car than I do!

What response time is he after?
Reason for the Question is that you could use PF750 or control techniques drive that will control the motor with the attached feedback device. This will give better than closed loop vector control of a squirrel cage but slightly less performance than a matched servo motor drive pair.

It all depends on the what performance you require from the servo motor.

I don't believe the positioning will require a close tolerance. Plus or minus 2mm over 1500mm travel distance will be fine. Speed I'm not sure on just yet. Probably 750mm/s at a guess. I have time to research if needed. It's still a few weeks away.

I didn't know you could use a smart AC drive on a Servo???

A year ago, I used an ACS800 as a servo drive from abb together with a controllogix&1756-M02AE board to handle the drive (+/- 10 vdc), motor has no name plate but 1000 rpm, 347 vac, 84 amps according to original drawings. My application was a flying cutoff i had no problems at all, ACS800 also has a firmware option for motion control. I also considered COMPAX3 from parker, parker has a good software to match drive to motor, it's worth a reading, www.compax3.com.

I used 3rd party motors on most projects. The important part is having the right cables and feedback option on the drive. You can easily get the required parameters from the motor data sheet you download from the maker's website. Unless, of course, that maker is no more, like indramat.

CapinWinky: Indramat is now part of Rexroth and their website is:
http://www.indramat-us.com/

Which is part of Bosch, I know. Try and get a data sheet for a 10 year old indramat motor. You'll have better luck asking random Germans in the industry if the used to work for indramat than that website.

I dunno - their site says all you have to do is ask:
http://rexroth-us.com/blog/find-indramat-manuals/
But, no, they don't have them available for download, you have to call...

I have setup many ABB ACSM1 drives with 3rd party servo motors. Feedback matching is important, as is good motor data.