I know there is a lot of posts regarding this application but all of them are closed and there is a solution I want to run by you. I got the same situation with 2 cylinders lifting a bottom frame about 4” both of them are acting in synchronous motion. I can’t put anything in the middle-thus 2 cylinders, see pic. I have read all of your cautions words and agree with them all but budget and geometry puts me in a corner on this one (I'd rather use ball screw cylinder but they are pricey).

I was thinking of modifying cylinder attachment point to make it more accommodating for different cylinder motion travel. I was thinking of putting 2 springs rated at 22lbs. The fixture being lifted is 30lbs, so I was thinking until both cylinders are lifting 15 lbs., the spring will take in displacement vs. twisting the frame being lifted. Not sure if this will work in up and down motion. See picture, give me your thoughts.

Thank You

Pictures Link:
https://drive.google.com/folderview?id=0BwyxiYqYHf...