how to move with constant speed using wind then take over with stop animation

for an animation i’m working on, i need quite a view objects to move with a constant speed.
Over a system of conveyer bands, in the past i did that width the game engine.
in short i had 2 methods for this.

  • I used collision detect to do a scripted move of coliding object
  • I used physics and a moving plane breader, object fell on moving planes and it worked.

Now though the situation is a bit different that i need to do by stop motion " i ", on certain key frames.
As i have to do some movements that would not fit in my past methods.

But i have to move a group of objects where the group grows in number of objects with a constant speed.
Now i was thinking maybe there are other ways to do this… using wind force, till a certain direction and then take over with hand stop animation ( loc-rot insert frame), …

but when i animate the “animated” option on the object that is moved by wind, jumps back to starting position…