Jim Wilkins wrote:



The pump motor is 3-phase, so I suppose I could install a VFD (they
probably have extras on site) and use a second prox sensor to cause
the speed to ramp down, but it would be better if I could just stop
the motor. And, there really isn't a good place to mount a magnetic
brake.
VFDs can deliver both dynamic and DC injection braking to the motor.
If you wanted to avoid any change to the hydraulics, you could set up a
little PLC or even some relay logic. Add a sensor for "near", and have the
VFD slow the pump motor to, say, 10 % when the near sensor trips, then
command stop when the index sensor trips. This should get much more precise
indexing without touching the hydraulics. A bit of tweaking with the
positions of the sensors and the VFD programming should get you at LEAST a
10 X improvement.

Jon