[Leo M]

OK, I took another shot at it. I may well be working under restrictions that are excessive or unnecessary, but Hey - that's part of the fun. My last sketch would not work for the reasons pointed out by Mr. Green, and also because my line-up had a shunt between the two ports on the cylinder, so it wouldn't be locked in place. Here's another attempt - it adds a 60 psig regulator ahead of each solenoid valve. Now, the shunt line is eliminated, but the system is still protected from overpressure. This design does add a component, but regulators are reliable and (usually) trouble-free. It does give you the option of setting the pressure to the extend and retract ports separately, so any force imbalance due to area can be corrected by changing the pressure. At this point in the build, it is academic, but brains need exercise as much as muscles, especially as we get older (you'll find out). Besides, this is a good thread, and I hate to see it end.....