What with all this talk about having to replace bits of fuel line etc etc I was wondering why it can't be done with Flexi copper ...........?
This is probably over thinking it but I thought it could be not a straight line link but with a hump/bump like a caterpillar mid "stride"
That work for vertical movement say but what about horizontal movement? Plus the reaction you'd get with dissimilar metals
On the other haaaaand .... how about three in-line "omega" curves set at 60 degrees to eachother? Bit of spring in three Axes ought to do it no?