This is I think a simplification of what I ultimately want, but it’s where I would start… Say that in 2D I have a box, a beam(except ultimately not of straight section) that I want to push and pull from one end while somewhere else along it is a fixed “pin” (I show a cylinder section but it can be a single point) on which it rests and will slide. Can this be done? Imagining paths and constraints it sounds like it’s just a rearranging of things I’ve done before…

I can’t find a way to do this. Certainly, the second constraint is going to be impossible.

This is the kind of problem that is best solved by physical simulation - there are no mechanical joints here.

A piece of cake actually. The answer lies in simple geometry: “If a line is tangent to a circle, then a radius drawn to the point of contact is perpendicular to the tangent at that precise point”. Bongo has the tools.

James.3dm (91.6 KB)

A curved beam however indeed seems a bridge to far.