KevinL: that’s not why. Jamincan: The train would sag, and wouldn’t form a straight line on straight track. The system, kinematically, would be underconstrained. In other words, if you were a giant, you could reach down and twist and tip the train and it would stay in the pose you placed it in. That’s bad.
I have been trying on and off for a couple of years to make an animation for you guys (knowing this would come up and someone would ask eventually!) about why the trains are articulated the way they are. There is a bug in SolidWorks that prevents me from completing it (I have an SPR in...). I may just make a little model out of LEGO and a video for you instead. It’s immediately obvious why it’s configured the way it is if you can feel it with a model.
I have been trying on and off for a couple of years to make an animation for you guys (knowing this would come up and someone would ask eventually!) about why the trains are articulated the way they are. There is a bug in SolidWorks that prevents me from completing it (I have an SPR in...). I may just make a little model out of LEGO and a video for you instead. It’s immediately obvious why it’s configured the way it is if you can feel it with a model.