Hello Arch,

I think of multi-center turning and eccentric turning as one and the same;
however, in the manual that comes with the new Escoulen Reversed ball and socket
chuck, which I received as a Christmas Present from my wife, they define the
action of the chuck as being able to do three types of work:

1. Turn off center with the axis parallel to the spindle
2. Eccentric turning, in changing the angle of the axis
3. and combining both of the previous possibilities.

The chuck is currently mounted on my Nova DVR Lathe and ready to try out, as
soon as I can decide what I want to try with it.

In essence, Number 1 above is the same as placing a piece of wood between
centers and then offsetting it from center the same amount on each end.
Number 2 above is the same as placing a piece of wood between centers and then
offsetting the tailstock end off center, which is what happens with the ball and
socket chuck. I don't know of a way to accomplish the third, which is a
combination of both forms of offset.

Jean-Fancois Escoulen considers the work done by his ball and socket chuck to be
eccentric. Robert Sorby considers the work done by their eccentric chuck to be
eccentric although it basically performs the actions described in 1 above. It is
all multi-center turning.

Fred Holder
http://www.fholder.com


In article , Arch says...

Even with no abbreviations, acronyms or insider jargon the terms used in
eccentric turning can be confusing, at least for me. I think of
eccentric turning as limited to either "multi axis between centers" or
"single or multi axis on a single center not concentric with the spindle
axis". To me, inside-out, pumping, oval chucks, rose engines,
ornamental turning and voodoo are all separate entities distinct from
eccentric turning. This may not be accurate nor a good way to consider
eccentric turning.

I hope Fred, Ken, Charlie and others will post an outline and/or suggest
terms that we can all use to describe turning that's not on a single
axis that's coaxial. Unless, of course, I'm the only one who gets
confused and fits another definition of eccentric.


Turn to Safety, Arch
Fortiter



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