Hi, like i said i have worked on the open center valves and now i have done the prototype and started to test it.
The system working pressure is 22 Atm, relief pressure is 2-3 Atm with a current drain of 1,5-1,8 Amps and the pump at 20% of "gas". The valve has a dead-zone of 4° per side and in the center position the cylinder is well locked.
The proportionality is very good and the effort needed to rotate the valve is not much, but i have to measure it. In the video below i test 3 different rates, normal, high speed and something like an "inching mode" and it seems to work well in all the ones, so i am quite satisfied.
https://www.youtube.com/watch?v=6rOSZWjEAQI
My greets,
Enrico