Problem with FBX import

I want to animate a character like in attached picture. So I created in 3ds max a sphere and two cylinders (just a test model). Then i attached them to three different bones. Then i animated all this stuff - cylinders are fly out of sphere and then go backward. I tried to import all this stuff to UE4 but here is a problem. All parts of robot imported separately. How can I fix this? Is it necessary that all bones be joined together before export?

227804-безымянныи.jpg

alt text

alt text

Yes, you should have a root bone for it to import as one skeleton. The hierarchy should be one root bone, and then one child bone per object.