Roller end caps from pvc or nylon Help!

[m_c]

Looks fairly easy to do, however an idea of tolerances are needed.

Is the part to be a pressfit into the roller, or a slight clearance fit to allow it to be glued/bonded in?
Is the recess in the rollers consistent?
i.e. are they a consistent size, and true.
If they're not, then it may be better to machine the shoulder, press/bond them in, then machine the through hole/bearing recess/belt groove to ensure things run true.
I'm guessing the bearing will be a pressfit?

Also, how many?

It's not a hard part to make, however there's lot of potential for things to not be quite right without the above information.