I just wanted to post a reply.
I increased the input voltage to the controllers to 65v. At this voltage, I can rapid at 350 ipm. I can only stall the motors if I step on the machine and push hard against the motion. At 300 ipm, I have to stand on the machine and push even harder. At 250 ipm, I stand on the machine and push against the motion, and unless I am realy leaning into it, the machine pushes me off of the table.
So, it is fair that I am very impressed with these controllers, and this was an excelent "upgrade" to my previous configuration.
Thank you very much Keling. Awesome controllers.