"Ignoramus11290" wrote in message
...
With the original Bosch drives, my 145v motors, etc, the mill was
capable of 200 IPM rapids. Right now I have a 70v power supply with
30A8 drives and the top speed is 60-70 IPM.

My question is how much am I losing, in reality, but having faster top
speed. My feeling is not much, but I want to know.

This is not an entirely idle question, as I could install drives that
match motor voltage (30A20AC or 25A20AC or some such). They would use
120 VAC as power source.

So, would I see any improvement in anything valuable with higher top
speed or no?

It probably depends a lot on the type of job at hand, but for the stuff I do
the difference is pretty insignificant. I ran a tyical job through the
simulator on SprutCAM (my CAM program) which estimates run time and tried
rapid speeds of 65 ipm (my mill) and 400 ipm. The difference in run time
was less than 10%, AIR. If you have a sample design, I can run that through
the simulator and give you ballpark data.