New member here from Richmond VA, I run a small job shop with a few antiquated cnc machines, Bridgeport Romi w/ Fanuc Oi-T controls, Milltronics VMC 30 w/ centurion 6, Acer 2-axis retrofit with Acurite Millpwr, and the recent addition of a 5 x 10 plasma table that I built this past summer.  

The Millpwr unit has effectively lost it's mind and Acu-rite wants a little better than $10,000 to update the controls since they don't sell constituent parts only entire kits...  The analog servos are in great shape and the machine scales on it that are less than a year old, and after getting my feet wet with the stepper system I built for the plasma table I'd really like to switch the acer over to some mach3-friendly controls.

I've been reading about the dspmc from Vital Systems and from what I've gathered so far I think it's going to be my best option for controlling analog servos with separate linear encoders.  What I am unsure of is the general hardware profile that I will have to construct for interfacing the pc to the dspmc to the servos, ie. which drivers would be best suited for these motors (140v), suitable bob?

Hello rvain:

I retrofit an older 80's vintage CNC mill, with analog amps, and DC motors, with the dspmc controller. It is an EXCELLENT controller, and certainly worth the effort to get working. No big surprises; just tracing wires, making wire diagrams, removing the old stuff you don't need (which was LOTS!!), new AMT-102 quadrature encoders (excellent little encoders from CNC4PC, 45.00 ea.), making a new control panel with a 17" LCD screen, put a little Foxconn mini-computer in the original console behind the LCD screen, new 8-Relay bank 24v, and your done. Runs better now than the original machine when new! Same motors and amps; same limit switch wiring; same encoder wiring; same home switch wiring; They have two types of I/O boards, one direct to the DB25 for TTL signals, and one with full optical isolation 24v. I/O. You will use both types. More I/O available than you could ever use! Vital Systems motor tuning graphical interface is like having a 17" color oscilloscope, with every motor control function tuneable in real time, showing the accel/decel curves as you make adjustments. If you used a touchsreen and one of the VistaCNC pendants, you could forego the labor of making a control panel with pushbuttons, except for an E-stop button, and maybe a feed rate override pot.
JM

Upon re-reading your post, a little clarification regarding existing Amps and "scales" would help; apparently Mill is not a 3 axis machine. There are many kinds of Servo's and Amplifier/Drivers available. Also, there have been vast improvements in CNC control hardware and software since the 80's, as you must realize; the differences are like night and day!

Getting away from the costly$$ proprietary CNC controls is always a good move.