drives for 140 volt dc servo motors

Can anyone recommend suitable drives for sem 140volt brushless servo motors 3nm torque with tacho.
Or would I be better to repair my anilam servo drives.
They were working fine, but the z axis drive leaks voltage to the motor ( enough to make a noise in the motor, I think it was 13 volts)
The x axis drive has stopped working, the power led is off on the card but there is 140volts dc in, and +24v , -24v, are correct, all the fuses are ok.
The current control is anilam GXM but has been giving a few problems and I think the time is right to change to linuxcnc.

Any advice appreciated.

edscrane1 wrote:

Can anyone recommend suitable drives for sem 140volt brushless servo motors 3nm torque with tacho.
Or would I be better to repair my anilam servo drives.
They were working fine, but the z axis drive leaks voltage to the motor ( enough to make a noise in the motor, I think it was 13 volts)
The x axis drive has stopped working, the power led is off on the card but there is 140volts dc in, and +24v , -24v, are correct, all the fuses are ok.
The current control is anilam GXM but has been giving a few problems and I think the time is right to change to linuxcnc.

Any advice appreciated.

You may be able to get suitable velocity servo amps from Copley or AMC on eBay
for ~$50 - 75 each. They are really good amps (seem to all be made by the
same outfit under different labels) and Copley at least has all the old manuals
back to their beginnings online.

Pico Systems and Mesa have analog-output interfaces for velocity servo
systems.

You may not need the full 140 V supply to get reasonable feedrates with these motors.
You can calculate the supply voltage needed for any speed.

I could also suggest the Pico Systems PWM servo amps and PWM controller.
This would be especially good if the tachs are worn out. Without tach
feedback, it may improve smoothness if encoders with higher resolution
are installed, but check the resolution of the encoders to see what they
are. (If it has resolvers, we have adapters for that.)

Jon

Thank you for the information, I will do more internet searches for the drives you recommended.

I was trying to keep the drive input voltage to 140v dc because of the transformer already in the machine.

Still got a lot to learn, but getting there.

you may find repairing the drive is an option , the biggest problem with all the older drives mostly is dry'd out capacitors and the settings creap over time
so you may find that the inputs just need a tweak , or the odd cap needs changing , if your electronics capable that is

edscrane1 wrote:

Thank you for the information, I will do more internet searches for the drives you recommended.

I was trying to keep the drive input voltage to 140v dc because of the transformer already in the machine.

OK, my PWM servo amps have been tested to 122 V and were designed to
go up to 160 V. I could test the amps at 140 V if you are interested.

Jon

andypugh wrote:

edscrane1 wrote:

Can anyone recommend suitable drives for sem 140volt brushless servo motors 3nm torque with tacho.

Just a tacho, or Hall sensors too?
I don't see how you can run a brushless motor with only a tacho.

Wait a minute. Brushless servo motors and Anilam drives?
That doesn't make sense. Are you sure these motors are
brushless?

Jon

I always thought they were brushless, will try to find out. The x and y use linear scales as measurement and the z has a rotary encoder.

my mistake, BRUSHED DC motors. Obvious when you look for the brush caps.

Thanks for pointing this out.