[Kevin Sevcik]

I don't do a lot of linear mechanisms like it, but I'm mildly concerned about your 4 piston extend-o thing binding up the linear rods. The ratio of bearing distance to top-to-bottom distance seems dicey with the off-center placement, but looks like it should be inside the standard 2:1 ratio. The bearing distance to side-to-side distance definitely isn't 2:1, so you could have a problem there, though it'll help if the green bit is a little flexible.

With 4 pistons pushing like that, I think it'll move eventually once pressures equalize, but if one pressurizes sooner, it could bind things up until the others catch up sufficiently. Best make sure all the lines are the same length.