My original Nerf Spinner Target is fine for Nerf Darts, but weak on Nerf Balls. Putting 3 layers of paper CD Labels per side on them helps a lot, but... the weak spot is where the CD is glued to the Spinner.
In the picture, the original (3 inch) design is on the right and this remixed (2 inch) design is on the left. Note how much further the CD fits into the spinner.
I remixed it so that the CD with 6 layers of paper CD Labels (3 layers per side) fit into the now deepened, and wider, slot for the CD. The CD no longer breaks (so easily). Checking out the pic, you can see that I Hot Melt Glue the CD into place on the Spinner. I also add a good hunk of Hot Melt Glue to the end of ONE CD per spinner. This way, when the CD is through spinning (and it can spin several times with a good hit), it always comes back up vertical ready for another shot!