[DonRotolo]

Our single roller was a shaft, drilled crosswise every inch or so, with loops of latex tubing extending about 2". It was one long piece of tubing, threaded through all the holes, eliminating any problems with holding it in place.

We found that at times the tubing would collapse against the shaft, turning it into just a shaft with a grippy covering (which did not work as well). So, we added 4" long pieces of 1/8" pneumatic tubing through the same holes, these provide the 'keep-it-away" factor enough so that balls couldn't get too close to the shaft.

We use a FP motor and 2/3 of the gearbox, about 600RPM, via a belt that slips (so the FP doesn't stall). Works pretty well, but drive or turn fast enough and it's possible to lose the ball. It is very effective against the wall though.