as B moves to over A, ( A is a fixed point ) C slides up its guide slot and is stopped by a non compressible object and no amount of force can shift it further up. measurements in units. At this point >> how do I know how much pressure C excerts upwards. psi? Mpa? I hope I'm making myself sufficiently clear. I wouldn't be surprised if there are simpler ways to look at this. I've no doubt I'm using wrong words. (how to frame Q correctly?) Is this a fairly standard configuration? if so what's it called?