RE: Rambling hydraulic post that was: Multiple syncronized spindle question.

["Eric Keller" <eek105-at-psu.edu>]

Ray Henry says:

If using hydraulic rams is an experiment, go for it and report back.  I 
do know there is a fellow that has some plans to build a hexapod test 
machine using hydraulic rams.  My short answer for a production machine 
is I wouldn't.  Read on if you're interested in the details of why I say 
this.
...
Much snippage

It appears that the world is going to electric motors for Stewart Platforms.
Hydraulics are obviously a good choice for such machines.  MTS now sells
a very quiet hydraulic power supply unit for large numbers of American $.
Otherwise, I can't stand to listen to another pump.  

I wrote a digital controller for a hydraulic load frame.  It works very well,
except that it does have significantly lower errors once the fluid is up to 
temp.  I am porting the software from dos to RTlinux to see if I can clear
things up using a floating point controller, because I am having numerics issues.

I'm sure you could put servovalves on tracermills and get good performance.
I don't think I would do it unless my aversion to soaking my hands in hydraulic
oil magically goes away.

Eric