I am creating a dynamic block of a crane, in Plan.
We received it in and I need to add dynamic features, because it's being used lots on a particular job and it is taking the caddy ages to mod it.

The problem I am having is visually simulating the boom of the crane raising and lowering.
If you look at the block, what I need is for all of the various line end points to concertina closer together in X, while remaining the same width in Y.

I've made various attempts trying, but each has lead to a mangled mess.

Any advice or ideas?