I'm looking at adapting a small, maybe 3"or 4" chuck to my 5C spin indexer to make it more useful for larger diameter but axially short parts that don't have to extend into the spindle. I have other means of doing this but it occurred to me this might be handy for common rotation angles. I've seen some chucks with integrated 5C arbors, or machinable 5C backplates which could adapt to a plain back chuck - maybe even correct a not-so-accurate cheapo chuck. My 5C Spindex is a Bison which is a better QC than some of the knockoffs. But I'm almost to the point of just dropping the 5C headache & making a dedicated housing block more to my liking. But that would require replicating the typical dividing plate. Hence the question. I will have to think about this some more. Project number 784.