track to and rotations

Hi all:

I want to model an engine which is supposed to work as a real one. And it is being quite a pain because things rotate in ways the shouldnt when I use “track to”. Then I try to avoid this rotations by using constraints on rotation, and then the track to stops working.

Know what is happening?

Post a little blend file with an example of both situations


Well, I finally managed to do a stable system of parents and “tracks to” to get my engine. The trick (I imagine) is to align every element properly, seems to be quite sensitive to that!!!

But now I’ve got a bigger problem!!!

I want to rotate a cylinder with its axis out of its body. I modify the position of the rotation axis by moving the whole object in edit mode. And what I get is that I dont have a “soft” rotation. When I rotate the object all the values in the Transform Properties window change in a way I dont understand.

Some help on this???

Thanks in advance