Help - How can I simulate a belt/chain going around the path?

I am trying to simulate a modular belt going around its pathso I can figure to what diameter roller I need. I am having troublegetting this to work. Ive tried creating a sketch, converting it toa path, then mating the belt module sketch block and dragging itaround the path. this works fine for (1) module, but when I addmultiple modules everything goes downhill.

What would be the best way to do this?

Attached is an image.

SolidworksMotion Studies