SWI Sport B3 with ProtoTRAK M3, Looking To Convert

Hello Everyone,

So I have an SWI Sport B3 mill with a ProtoTRAK M3 control system currently on it. I understand that it uses AC powered encoded servos for all 3 axis.

I would like to convert away from the ProtoTRAK because I have had to repair it once... and that was a very expensive nightmare. In my spare time I am a Linux Server Admin, so I figured I'd try switching to LinuxCNC since It has a great community and would provide me with a much more advanced control than what I currently have.

EDIT:

Ok so I was asking about how to drive the motors but I think I have found the current thread about these Proto Trak M3 systems here:
forum.linuxcnc.org/forum/38-general-linu...with-mesa-7i92-7i85s

Hopefully I can get to where they are and start asking questions from there. We will see how this all goes.

You could also do this with the Pico Systems PWM servo system, assuming the encoders or motors provide commutation information ("Hall signals") for the motors.

We have a PWM controller and brushless PWM servo amplifiers.

Jon

It was determined in this thread that the servos are ran by differential PWM in locked antiphase mode (50% = 0 drive). I'll let you be the judge if your drivers are able to drive such a servo.

I'm not sure about testing a different driver since another user has successfully been able to get a mesa driver to work, and replication is far easier than attempting to set something up from scratch.

KroniK wrote:

It was determined in this thread that the servos are ran by differential PWM in locked antiphase mode (50% = 0 drive). I'll let you be the judge if your drivers are able to drive such a servo.

I'm not sure about testing a different driver since another user has successfully been able to get a mesa driver to work, and replication is far easier than attempting to set something up from scratch.

OK, so you are planning to keep the existing drives? That's great if they are in good condition.
Yes, it is possible to use our controller to control such drives, you just add a 50% offset to the PWM command, and don't use the direction output.

The downside to synchronous antiphase is the motors and drives tend to run hot. That's why I set up my drives to
run in sign-magnitude mode, so that at rest there is no current output to the motor.

Jon