"rangerssuck" wrote in message
...

snip

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.

As always, all thoughts (especially kind ones) are welcome.

Since they need to stop accurately, they probably had in mind switching
valves to stop the index instead of coasting to a stop. On the input side
of the motor you could have a 3-way valve that sends the pump back to the
tank and blocks the motor port at the same time. A valve to block the motor
OUT port should lock it up. For the hammer of sudden blockage, you could
use a relief valve or even have it switch to a restriction to ramp down to
position.

It's possible this already has the valves in the system and one isn't
working properly or sticking. We had a machine that used linear positioning
with a hydraulic cylinder, it had cartridge check valves and wouldn't
position correctly when the check valve was bad. Our larger machines have
hydraulic positioning but you proportional valves to ramp to position.

RogerN