backlash was Re: Comments from expert PID programmers?

Ron,

Bob W didn't write that, I did.

And it has now been taken so far out of context that it no longer has
the meaning I wrote...

Dennis was proposing a compensation scheme that did not take into
account the reality that the cutter has the ability to Effect/CAUSE
axis slide movement simply by its interaction with the workpiece. I
said as much and then added this part you've re-posted.

FWIW, in every shop, and in every school-based training program I am
aware of--also in most every machinist text I've ever seen--there is
an INITIAL (read "first" below) warning NOT to climb cut because
backlash CAN cause the cutter to grab.

That climb cutting CAN be done, and IS done, is NOT the point. the
point is that it involves extra dangers and considerations that a
newbie may not realise. (And in case anyone's forgotten this group is
EXPRESSLY oriented AT newbies)

Ballendo

P.S. Anybody care to see what machinery's handbook over the years has
said about climb cutting?

>In CCED, Ron Kline <ronkline@...> wrote:
>
>>>BobWarfield wrote:

(No, Ballendo wrote; but this is now completely out of context!)

> > > Part of the reason the FIRST things a manual machinist is taught
> > > is NOT to climb cut on machines with ANY backlash...

>This is by no means correct , on full size equipment we do this all
>the time . If you know what you are doing and know your machine it
>is a very standard practice . Climb cutting gives a much better
>finish. I had never run a machine without backlash until 2 years ago
>and I started in 1971.
>
> Ron Kline