About 26 years ago, I worked briefly on Miprom 21s and Allen Bradley 6010 drives. I can't claim to know much about them, but I did find an SCR that wouldn't turn on once, which made a huge vibration...
Anyway, What exactly is the downside to importing an industry standard DC drive? No S-curve being generated by the Miprom 21? There are some S-curve generators around. Kind of like MCEs' now-obsolete VVC-1 pattern generators. Feedback concerns? Stick a tach on the drive sheave. Run command from the Miprom goes to an analog pattern generator, then feeds the drive cabinet, along with the usual plethora of safety interlocks.
But of course, any modification must be UL listed, and we must avoid exposing ourselves to liability.
