Object child of two parents Imagine this scenario. Crane 1 picks up a boulder and puts it into a cart, the cart moves, stops and then the boulder gets picked up by Crane 2. 

Armature wise everything works. I'm having difficulty transferring the object

My issue is:

Boulder is child of a bone in crane 1 using constraints. it gets moved by the animation but I can't get the crane to "release" the boulder. Setting the influence to 0 leaves the object where it was before it was picked up. 

I can get round this with 3 scenes, but I want to just use 1 in a continuous flowing animation

Whats the proper way to do this?

Thank you in advance for any help
Sean
For this...



...you can animate the Visibility of three Copy Transform Constraints (Multiple Child Of constraints will not work) on your Boulder, one for each crane and cart:



The only trick is, at the end, you must keyframe the transforms by performing a Copy All To Selected on the Boulder.  This will keep it at it's final resting spot.  Then simply remove visibility of all constraints: