[PaulEleven]

Originally Posted by Joe G.

Try to avoid putting significant side loads on any pistons, no matter the size. They aren't really designed to take it, and it takes surprisingly little deformation to hurt a cylinder's performance pretty significantly. Typically, in designs like this, you'll see some other kind of structure which takes the brunt of the downwards load.

I would consider placing your inner jaw on some kind of linear guide (the IGUS components in the kit are a good choice, as is the REV extrusion, the Vexpro elevator bearing gussets, and numerous other off the shelf options), or switch it to a pivoting design. A small four bar linkage may be a good choice here, giving you the strength and ease of fabrication of a pivoting joint, while maintaining your desired linear motion profile.

Thanks for putting the four bar idea in my head, I'll never get it out now..... another sleepless night......