I'm thinking about adding a rotating lathe chuck as a fourth axis to my router but I haven't decided how to mount it yet so I'm researching for a solution. I found this chuck on Ebay that has a 5C shank, which I assume is the shaft with the key slot and threaded end(?). Is the 5C shank a straight or tapered shank? What is the diameter of the shank? It's hard to find standard dimensions like that on the internet, I have tried googling. http://cgi.ebay.com/4-3-JAW-5C-SELF-CENTERING-LATHE-SCROLL-CHUCK-SHANK-NEW_W0QQitemZ260216596717QQihZ016QQcategoryZ25292QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

I found something. In this thread neilw20 posted a document that lists dimensions of different collets: http://cnczone.com/forums/showthread.php?t=51930