Re:OT Live Center-WAS lapping-was-Digest Nu mber 4217

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Andy Wander <awander@v...>
wrote:

> What's incorrect about the term "live center" for a ball-bearing

center in a

> tailstock? I understand Live Center to mean one that revolves with

the

> work.
>
> Andy Wander
> Verrex Corporation

The correct term is that any center in the headstock is a live center
and any center in the tailstock is a dead center.

The introduction of the term live as pertains to function can be
traced back to WWII where untrained civilians were pressed into the
production floor and classical training went out the window.

I have not found any texts that refer to a ball bearing center as a
live center before 1945 even though the ball beairng was invented
in , I think 1903?? but after 1945 many texts refer to it both ways
and from the 1950's the prolific use of a ball bearing center as the
only deffinaton of a live center. Many texts state to put a dead
center into the spindle when using a faceplate.

I would not argue that your definaton is technically correct, but I
would put forth that many people do not use it in that manner.

I do think we are getting off topic here so I will not comment on
list on this thread any further.

And I would ask that unless someone has a technical reference with
history, that others do not post opinions on list.

I'll be happy to discuss off list however.

Dave