using older servos with new controller

[Telemaque]

My group has a three-axis stage controlled by an old Galil DMC-230 motion control board, Galil ESA-10-75 amplifilers and three dc servo motors (from Galil too, I think).  The board is mounted in an ancient computer running DOS.  To make matters worse, the hard drive seems about to give out.  We would like to leave the stage and motors alone but replace the controller and amplifiers.  We are considering using an NI PCI-7344 controller with an NI MID-7604 Motor Drive.
My questions are:
What are the main things to consider when matching a servo motor to a controller?
Has anyone done anything similar (using older servos, but replacing controller and drive)?
Should I just give up and beg the boss to buy new motors as well?

Thanks for any advice!

Telemaque

[AnalogKid2DigitalMan]

Been there and almost done that. We have a legacy DOS Galil based (DMC-630 controllers with SSA-12/40 drives) system with brushed servos that is on it's last legs.

Matching servo to drive amps- look at max currents, voltages, and inductances on the motors to see if drive can accomodate. Are they brushed or brushless motors. Also check if encoders and hall signals from existing motors and limits from stages compatible with new controller.

Personally, I would suggest new motors since you may not know their history of (ab)use and depending on their ratings, may be a minor percentage of total retrofit cost. You may also want to have the stages sent out for refurbishment if time permits. They have probably seen a lot of use with little or no cleaning and lubrication. Mechanical wear also takes it's toll. On the system I mentioned above, we were experiencing loss of accuracy and repeatability- the lead screws and nuts were trashed.

Just a couple ideas to start with.

Good Luck

AK2DM

[Telemaque]

Thanks AK2DM,
    I suppose that you are right; if I'm already buying a controller and drive, why not buy newer, more dependable motors.  The only reason I hesitate is the way the old motors are mounted to the stage...the holders would not adjust for another size motor.  Anyway, I could spend a few hours in the machine shop and come up with something.  Thanks for the advice and warning.

Telemaque