CAD Models for Idea - Engineering/mechanical 3D models.

With this project I am trying to have a 3D design of a concept for a part of a larger device designed with high quality and I also want this part to be 3D printed for weight and cost so these designs are beneficial. I am trying to create an oval shaped half enclosed track (approx. 9inchL 6.5inchH 3/4inchB, all sizes are open for discussion as trying to make it as frictionless as possible) that has rollers or ball bearings on the sides and center of the track to allow a 3d printed chain move around this track with very limited friction. pushing around a series of connected hollow chain links(Also need to be designed) that have about a cubic inch of open space inside them. I have some designed pieces which I will attach please note I am no artist and took a stab at what I wanted to show some sort of concept so most of this would be done via conversation and basic sketches. Let me know if you are interested.