Hi Mark, If the new Larken drives we just got back for my Hurco TM-5 bed mill end up working well, we might be going with 3 more for this mill. The Excello died when the company I bought it from had a power outage. May be an easy fix to get it going in that case I won't retrofit it. I will just clean, paint and flip it. I'm going to take off the 4th axis and use it on my Hurco. I have not gone though the Excello electrical drawings yet. I may be able to use the stock drives. There was a company called Skyko
www.skyko.com that Produced a board called a pixie but from what I can see they have been discontinued. This is a step and direction input, analog voltage output controller board intended to connect to a brush or brushless motor amplifier accepting analog control voltages (+/-10v or +/-5v range). This board accepts encoder inputs from the motor and commands a motor amplifier to move the motor shaft to the desired position as indicated by the incoming step and direction signals. As of yet I don't know if there are any other companies producing such a product. If anybody knows of one please let me know. I will be posting more as things progress.
Dan