We used a similar approach on our robot with 6 rollers (3/4" PVC tube with 2.5" pool noodles).
We use the pvc as a shaft and attach plastic #25 sprockets between each endcap on the pvc. We have tested this collector mechanism for 1 week without any significant failures in the rollers.
For most teams without polycord, this is a simple workable solution.
Check out our
video or gallery. We should be putting up a video of our robot collecting 20 balls and then dumping them in 20 seconds !