backlash was Re: Comments from expert PID programmers?

>In CCED, "Dennis Schmitz" <denschmitz@...> wrote:
>So if the controller knows the thrust reversal is coming, it can ramp
>the speed down (even a very steep ramp should work), proceed across
>the dead zone at a pre-determined safe speed, and hit the other side
>gently, watching the current draw to know when it was there.

Uhhh, No.

There is no "pre-determined SAFE speed"

You're forgetting that the cutter is ENGAGED with the material. Very
often the forces involved are enough to SLAM! the work from one side of
the "dead zone" to the other!

Tools break, metal flies, folks get hurt.

Part of the reason the FIRST things a manual machinist is taught is NOT
to climb cut on machines with ANY backlash...

Ballendo