[Frank Lee]

I think you need to get the edge of the disc seated into the lip on the edge of the rim otherwise the disc will get a lil off-center then centrifugal force takes over and strains everything.

Also I have a suspicion that the zip ties are being forced to bend sharply (more than 90 degrees, and with very small radius) around sharp holes in the rims. You might want to come up with a new strategy, or put a backing of some sort on there to make those bends gentle.