mechanically improved Marble Machine #3

My friends and I have had a few troubles with printing and operating this model.

The tallest legs which are directly opposite Tulio's name kept getting shifted or breaking before they joined together on the track above them. I thickened one and added a rib to it, and built a bridge to an adjacent track on the other.

Also the second fastest track has this leg protruding into the path of the marbles. Often marbles get caught there so I moved it out of the way.

This worked great on my pr