Contouring and CVV

Fred,

An interesting approach... So the cam system would insert "helper"
f/r change blocks (or just add "F"-words to given blocks) in order to
optomise the already present constant contouring algorithm? Sounds
like a winner...

And the point about centerline vs. "tool" velocity is well taken. I
think most experienced programmers are aware of this and DO
make/insert F/R changes when programming c/l, but it sure would be
easier if it was a CAM "menu" item/option :-) (Or in the control, but
That's not your "bread"<g>)

Thank you for this post! I'll be watching for a Vector update...

Ballendo

P.S. What form of contouring do you consider the "best"? I hope my
post was clear that when I use the term "CVV", I mean the control
will attempt to maintain as "constant" a velocity as possible,
toolpath/machine physics considered. So the actual f/r may be slower
than is programmed at certain "tight curve" areas in the toolpath,
but it will ONLY be slower for as long as physics dictates.

--- In CAD_CAM_EDM_DRO@y..., "imserv1" <imserv@v...> wrote:
>If one were to combine the level of continuous contouring, either
>that found in EMC or the ones found in say Master5 or Flashcut with
>an automated Cam system that could also react to distance to and
>from a specified angular change and an automatic feedrate change,
>would it not be possible to fine tune the system response,
>particularly say to a certain devilish corner in a family of parts
>(say corners on a door) such that the performance of the hobby class
>system approached that of the $20,000 hardwired box?
>
> There are some distinctions that I have seen between various
> implementations of continuous contouring. Constant velocity being
> only one permutation, and not necessarily the "best". One problem
> still to be adequately addressed is the one of the "crack the whip"
> effect found when cutting a tight centerline radius with a larger
> cutter. The effective feedrate is multiplied many fold and unless
> the controller is using cutter comp there is no data to control the
> actual feedrate around a hairpin turn. This makes cutter comp a
> minimum requirement for 2D continuous contouring.
<snipped example>
> Best Regards, Fred Smith- IMService
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