Re: [CAD_CAM_EDM_DRO] Re: Re: Re: Hexapod question

alex wrote:

>Why not to make legs of hexapod of hydraulic cylinders with feedback
>encoders?
>Position can be locked in place with the valve.
>
>

No, not really. If you have a valve that locks the cylinder, then there
is a delay
and a jerk when the lock is released. The standard system is to use
Moog-type
proportional hydraulic servo valves, which are VERY expensive. These valves
need to have dither added to the command signals to keep the spools from
sticking. You need 12 flexible hydraulic lines, 6 $5000 servo valves, 6
high-resolution linear encoders, and a huge hydraulic pump, in the 5 to 10
Hp range. Yes, you can do this, and it will work, but it is "old school",
fantastically expensive, high maintenance, VERY noisy, dangerous to
work on (a ruptured hydraulic line, or even a pinhole leak can be fatal!)
and gobbles up a huge amount of electrical power, even when sitting
still.

Jon