Hi Jim,
Thanks for the detailed post. That’s exactly the kind of precise data I was looking for.
I did read the last sentence of your paragraph, but I misunderstood it. I thought you had no inner velocity loop. That can be done, but it’s tricky and depends on very good mechanics and servo control.
If you don’t mind, I have one more question. Can you describe the control of the Z-axis on the BP clone mill in a little more detail. Is it correct to assume that the analog input to the stepper drive is a velocity command? If so, then your velocity loop is around the load, correct? That is particularly interesting given the compliance of the air spring in the transmission. What are the specs on that? Does it provide a lot of force relative to the Z-axis mass? How was this axis to tune?
Ok, I guess that’s five questions. Or, one question with five parts
I appreciate your time on this. It’s always interesting to hear what other knowledgeable people are doing with their systems.
Best regards,
Warren