"Mike" wrote in message
om...
I'm looking for opinions and options. for expanding mandrels.
I've seen some cheap sets on ebay that have set screw in one end to expand
the mandrel. I've also seen the sliding taper version which could be
mounted between centers if needed.


Make one, or two in your case!
Machine a slightly larger diameter shaft than the hole size of the part. In
your case, 1" & 1-1/2" shaft would do it for each part. Machine the shaft to
a tight slip fit into the bore of the part, no deeper than the thickness of
the part. Drill and tap the end for a tapered pipe plug. Remove your new
"mandrel" and saw cut two radial slits about 1" from the end. Insert back
into the lath, add the pipe plug, insert part over the mandrel and tighten
the pipe plug securely.
Easy, cheap, and disposable. We machined many parts using this setup when I
worked at a shop years ago.
Greg