On Fri, 27 May 2016 08:55:50 -0700 (PDT), rangerssuck
wrote:

On Friday, May 27, 2016 at 9:51:29 AM UTC-4, wrote:
On Thursday, May 26, 2016 at 10:43:36 PM UTC-4, rangerssuck wrote:


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

Not solutions, but maaybe a kind thought.

I would post this over in SED. Much more up that alley than RCM.

And I realize that you are just starting to think about the problem, but do you have any idea of what are the requirements? How repeatable does it need to be. And how accurate? Obviously it has been used as is, but what is desired.

If you want it really precise, then you will need a way to close the loop and have feedback from the position. But just getting close may be all that is needed.

My own thought would be to add a valve and line. The valve would open when the pump is commanded to stop moving and would connect the pressure side to the return side. So even if the motor kept running , there would be no pressure to the hydraulic pump. May be a lousy idea as it would not lock the position.

Dan

I'm feeling like taking your approach one step further and connecting the two lines from the motor to each other should get the thing to stop on a dime. But see my response to Tim for more detail.

There was a hydraulic system used on aircraft, and probably in other
places, that used a so called "open center" system that worked as you
describe. See: http://tinyurl.com/gw652cq
--
cheers,

John B.