On 2010-08-20, Jon Elson wrote:
Ignoramus11290 wrote:
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.

I have artificially limited the speed of my machine to 72 IPM (60 IPM
plus a little leeway) to avoid expensive oopses! The machine and servo
drives will do 120 IPM, but I had a few accidents in the early days with
it, and thought it might be best to "slow down and save lives" so to speak.
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?
Probably not. All you'd do is reduce non-cutting time by a few seconds.
Unless you are making long traverses across the machine's working cube,
it just won't buy much. Increasing acceleration makes it possible to
make sharper corners, that is an actual advantage. But, you are highly
unlikely to ever cut anything above 60 IPM, so it could only make much
difference in production runs.

Jon, I think the same about it. A lot of safety is in my ability to
stop the mill quickly enough.

i