Another option might be to fabricate some better/new jaws for your existing
"basic" 4-jaw chuck that comes with 9x20 lathes, or to modify the present
jaws.

Pie jaw descriptions (and the pot collets) that have been discussed have
essentially been nearly full circle support for the workpiece.

You may be able to fabricate some jaws that have more support/grip surface
area (or modify the existing jaws) so that the perimeter workpiece contact
area is significantly much greater, but not an entire full circle.

I'm not sure about the jaw treatment on the "basic" chucks, but I would
expect them to be fairly soft mild steel, but possibly case hardened,
although not likely to be anywhere near as hard as typical/conventional
precision chuck jaws.

If the jaws are soft enough to easily drill and tap, fabricating a bolt-on
solution could result in a fully customizable workholding fixture.

As for penetrating a case hardening, if it exists, several methods should
allow you to anneal a couple of spots for fasteners.. spot annealing heat
generated with a dowel in a drillpress, torch heat, colbalt/HSS or carbide
drill etc.

I believe that keeping the workpieces near the spindle nose bearing will
minimize chatter problems.

--
WB
..........


wrote in message
...
On Fri, 17 Dec 2010 06:47:53 -0800 (PST), Jim Wilkins
wrote:

[...]

This chuck is fully 6" from the end of the mounting plate to the jaw
tips, which eats up a lot of work space and could be too much overhang
for a lathe with a thinner spindle.

That is has been my concern all along. I shall check with other 9x20
owners.

[...]

Michael Koblic,
Campbell River, BC