On my crane topic a large moc from Spain was given as a possible guide, the part that was odd was the mechanism for looking the telescopic sections together (when at max extension) then releasing them if the section was moved past its max (allowing it to be fully retracted). I built a copy of this to test and I just cant see how its meant to work (carbon copy except from elastic band placement  but it can only have one function at least I think) the original creator of the moc says it works but I cant find any pictures of the jib extended (pictures of it extended would also show how its meant to lock). Here's the link if you want to see a super impressive crane or decode the mechanism better than I have: https://itlug.org/forum/topic/7536-gru-telescopica/page/1/ IMG_0414 by michael waterfield, on Flickr Any thoughts on a such a ratchet or the reasoning behind the strange build of this one?