Need suggestions on boring some plastic wheels to a larger bore in quantity

[desbromilow]

Thanks Frank! Pipe chunks that large aren't readily available where I am. I wonder if I could make that outer band portion out of plywood, and slit it multiple times around the perimeter so it's like a collet, and then use a hose clamp to cinch it around the wheel?

hell yes - you're approaching the same problem the wood turners face with large hollow bowls. They make up a chuck with wooden sides, and then simply have a face" washer" which has bolts through to the backing plate - imagine a drum or banjo with the work piece inside, and a hole in the top so you reach in and access the work piece.