In article ,
charlieb wrote:

Once again, late to a thread.

Things to look into when considering a chuck

1. Mechanism for tightening and loosening the jaws
SNIP
A jacobs chuck key (either a short one like used
on a drill press or on the end of a long T-handle)
permits one hand tightening and loosening of the
jaws - without the need for a spindle lock. BUT -
and there always seems to be a "but" - this type
of key only works when the long axis of the key
goes in square to the long axis of the chuck - on
a jacobs chuck or a lathe chuck. There are
times - on some forms - where that isn't possible.
THAT is a limiting factor for chuck keys.

A normal straight T-handled allen wrench mechanism
has the same problem as the T-handled chuck key.
However, a "ball end" allen wrench lets you tighten
the jaws with the wrench angled back some towards
the back of the chuck. This capability may not
ever be used, but having it and not needing it is
better than needing it and not having it.

Having a form cover the chuck key area is a real pain when it happens.
In addition to the ball end Allen wrench, there are "universal joint"
type wrenches to reach into a covered area. I believe they come in both
Jacobs as well as Allen configured.

SNIP
4. Jaw Sets - how easy are they to change?

When a chuck maker can figure out a secure quick-change design... Well,
Doggies! That'll be somethin'. Having scrolled my backing jaws out and
setting themback in, turning jaws attached to auxiliary sets of backing
jaws is no solution in my view.

SNIP
9. Are the interior moving parts protected
from dust, dirt, oils, waxes, blood, insects,
pitch, sap, . . . A chuck that works
smooth and flawless when right out of the
box - but binds and chunks in use is nice
to look at but a PITA to use over time.

I own 2 Vicmarc chucks with enclosed backs. Having said that, Oneway has
been making their chucks with open backs since the beginning. Their
chucks are top-of-the-line and they design everything so well, I'm
thinking this is really a non-issue. At least when comparing Oneway
chucks to others.

--
Owen Lowe

Northwest Woodturners
Pacific Northwest Woodturning Guild