Various arbors used to hold cutting tools in an index for
machining or sharpening.  Solid arbor with spacer, washer
and bolt.  Shop made expanders with taper head bolt.  Held 
in collet, screwing in bolt causes expansion.  Commercial
5c expansion collet.  Taper head bolt is only screwed in 
enough to take up initial slack.  Collet closer on machine
pulling on loose spring loaded threaded end of collet 
causes expansion; allowing convenient use of the machine
lever close without stopping lathe in many cases.