[Azalin]

I really don't know much about servos so sorry in advance if you find my questions stupid.

Say I have this servo. What are the drive options? Will it work only with its matched driver (LXM32.D18M2) or can I get it working with another brand servo drive (same phase, voltage etc.)?

[Al_The_Man]

Just a quick look at the PDF's which are skimpy on details but it appears they are very specialized motors, encoders are sin/cos and the voltage is 300v synchronous AC Servo (not BLDC).
The drives are made for these motor characteristics, and definitely would be hard to sub any other drive, as it appears.
Al.

[Azalin]

That's bad. I've found this servo for only USD56. A nice steal. It is fast enough to use as spindle motor. Haven't purchased it yet but seriously considered. The matched driver costs $1k

Thanks Al.

[Goemon]

That's bad. I've found this servo for only USD56. A nice steal. It is fast enough to use as spindle motor. Haven't purchased it yet but seriously considered. The matched driver costs $1k

Thanks Al.

I wasted a lot of energy on finding the drives and cables to use some AC servo motors I aquired. I suggest buying the servos and drives as a package.

If budget is an issue,I would skip servos altogether. Just the cables can cost north of $200 (used) for some models. Seemingly cheap deals on used gear ends up costing a lot by the time you have bought all the drives, cables and PC interface boards.

[Azalin]

Unfortunately yes, budget is the issue.

Ok I'm skipping servos.

I have talked to a local spindle manufacturer. They make all kind of spindles. Mostly router spindles but he gave me some ideas. A 2.2kw and 200hz (12000 RPM) motor sounds ideal to me. My max head speed on the BT30 spindle is 6000 rpm so I can use 1:2 ratio pulleys to lower 12k to 6k.

Mill is an Optimum BF20L but I put BT30 to it. The largest tool I will use is 40mm facing tool.

Given that do you think I can use the motor I mentioned above?

Thanks.

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[mike_Kilroy]

That is Kollmorgen akm motor private labeled. It has a multiturn absolute 1v sine encoder. Motor sells for abt $ 1500.00

Our akd-p-00606 drive will run it fine and cost well under $ 1000.00

PM me if u wish

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[Azalin]

Ok simple question. What happens when you drive a 400v servo with a 230v drive? Will it work but make the half power because the volts is the half?

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[mike_Kilroy]

VOLTS give SPEED, AMPS gives TORQUE. It is exactly a linear relation for amps, and for your purposes, it can also be considered directly linear for speed too.

so in your example, if you have the amps the motor is rated, you will get the rated torque, regardless if volts are 120, 230, 400, or 480.

so in your example, if you have 230vac & the motor is rated 400, you will get 230/400 * the rated speed max, regardless of amp rating of the drive

[Azalin]

Good explanation. Thanks Mike.

So a servo that spins 6000RPM at 460v will spin about 3000RPM at 230v.

[mike_Kilroy]

Good explanation. Thanks Mike.

So a servo that spins 6000RPM at 460v will spin about 3000RPM at 230v.

yes.

[Azalin]

I wasted a lot of energy on finding the drives and cables to use some AC servo motors I aquired. I suggest buying the servos and drives as a package.

You are absolutely right. It's a pain searching a driver to get a servo working. Especially if one like me who has very limited knowledge about servos.

[Al_The_Man]

Can I get it working with another brand servo drive (same phase, voltage etc.)?

One advantage of using a system where the loop is closed to the controller, such as Kmotion/Kanalog, Galil etc, you can mix and match several BLDC motors and drives that are available fairly cheap out there.
I have picked up nice quality motors and used the simple Advanced Motion drives etc.
Al.

[mike_Kilroy]

You are absolutely right. It's a pain searching a driver to get a servo working. Especially if one like me who has very limited knowledge about servos.

Very true! Most drives only accept a single type of feedback and are limited to certain speeds, number of motor poles, and more. So a long search is required to find the right one.

Your alternative is to buy a state of the art latest technology drive that "does it all." Then you do not have all that search time. Make note of such drives for future use! That way you can utilize those $1500 ebay motor finds for $ 50.

One such is the Kollmorgen digital AKD drive that accepts resolvers, encoders, sine encoders, absolute encoders of many flavors (tamagwaw, renishaw, heidenhain, endat 2.1, endat 2.2, hyperface, DSL, BISS, encoders, halls, etc) and can run any servo motor from 2 thru 64 poles. And has analog input, step/dir input, and just about any digital input out there (ethernet/IP, sercos 3, ethercat, canopen, telnet, modbus, profibus, etc). And one that does autotune and more importantly auto phasing of motor to feedback. And is priced like the 'cheap' AC servo drives (not as low as the low cost BLDC ones). And can run a DC motor with encoder feedback or an AC induction motor (these are more unique applications). And has a nice easy to use windows GUI.

In all cases, double check with the manufacturer that your motor, feedback, and input requirements match their drive.

[Azalin]

Kollmorgen makes nice drivers but way too expensive.

People mention about VFD's that have the ability to drive AC servos with vector control, or something like this. However I could not find any specific brand and model that has that feature.

I'll be using the servo as spindle motor by the way. Max spindle speed will be 6000 RPM.

[skrubol]

If you're willing to get creative you can probably just take the encoder/resolver off the back and replace it with a standard quadrature/hall encoder and run it with a BLDC driver if you're not using it for positioning.

[Azalin]

Now I have a 6000RPM Schneider (BMH0703T32F2A) 1kw servo and an ABB (FMH2A09TR-EN43Z) drive. I guess these two cant be mated. So I was wondering a similar solution to yours. Remove the resolver, brake, encoder from the servo. Add a simple encoder and just take the hall sensor line and connect it to the ABB drive. I mean I'll be having only a motor+drive with index signal. Does this sound doable?

I use this to drive a BT30 spindle so positioning isn't needed. Just indexing.

[Azalin]

OR, without removing the encoder, just take the hall sensor output from the motor and connect it to the drive. I don't know if this is doable, too.

[skrubol]

Not sure about that driver, most AC servo drives tend to be very picky. BLDC drives often just want a hall signal, but work basically like a brushed drive beyond that. Just an analog or PWM signal for torque or duty cycle (I've got one drive that the PWM you feed it is the actual PWM that goes to its switching transistors.)

[Azalin]

What exactly is a BLDC drive? Can you post a link please?

[skrubol]

Brushless DC motor. AC servos are Brushless AC. The motors themselves are nearly identical, slightly different windings (though I have seen the motors used interchangeably by manufacturers.)
I've got one something like this one: https://www.ebay.com/itm/Advaned-Mot...ty!01983!US!-1
That one is a low-voltage (60VDC) version, I'm guessing your servo is a 208-240ish VAC servo?
I guess that's one issue with BLDC drives. They tend to be lower voltage than AC servos.