I have started an animation workbench some month ago.romartin wrote: but am not sure what you mean by a Plugger.
the documentation is on my website http://freecadbuch.de/doku.php?id=Animation%20Wokbench
there is a list of clips for the features.
the plugger connects a part to a vertex inside of an animated sketch.
there is a demo clip that shows the plugger functionality on a star motor http://youtu.be/v6oFOr8EW4U
I'm doing here the same like you. A sketch animates the rotation and the movements of the pistons.
the real parts are connected to the vertexes inside the sketch by pluggers.
I'm interested in a framework that allows me to animate without extra python coding necessary for the enduser.
So meanwhile a list of objects are created.
I'm now on the way to implement more complex patterns - a gearing system, a kardan wheel and currently the geneva wheel.
jmg works on a sheet metal tool and a unfold process. he has published this weekend his assembly animation workbench. it works similiar. With this tool you can interactive create an animation without extra code. See this
http://freecadbuch.de/doku.php?id=blog: ... verfeinert