Re: [CAD_CAM_EDM_DRO] Re: Cam track help!

It is VERY simple, and only sounds complicated. Calculate the change in
angle for the given move and with the diameter you can convert to a linear
movement along this path, also calculate the length of the linear axis move.
Use the Pythagorean theorem to calculate the length of the actual combined
axis movement. Figure out how long this actual move will take for a give
feedrate that you want. This time value is then used with just the linear
axis movement length to calculate the feedrate that should be supplied by
the controller. This, of course, assumes that the feedrate supplied by the
controller will be applied only to the linear axis and the rotary axis will
spin at whatever speed is required to keep up. If your controller works
differently then you need a different formula.

I have received so many requests for this information (and I even wrote it
up a couple of weeks ago on this list) that I have decided to make my
spreadsheet available to everyone in the files section. I will try to place
it there in a few minutes.

Daniel J. Statman, Statman Designs
www.statmandesigns.com

----- Original Message -----
From: "eferg2001" <eferg@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Thursday, August 22, 2002 11:46 AM
Subject: [CAD_CAM_EDM_DRO] Re: Cam track help!


> Dan,
>
> I would like a copy of your spreadsheet also. Not that I want to
> mill sine waves, but I'm interested in what your algorithm is for
> specifying feedrates on rotary axis projects using small moves.
>
> Regards,
> Ed Ferguson
> eferg@...
>
>
> --- In CAD_CAM_EDM_DRO@y..., "Dan Statman" <dan.statman@r...> wrote:
> > Depends on how much resolution for the curve you want, but at the
> sacrifice
> > of many more starts and stops if you do not have constant velocity
> > contouring. The reason it behaves oddly at the peaks is because
> you are
> > doing a tiny linear move coupled with a 1 degree angular move and
> the
> > feedrate does not know what to do. For the code I supplied Mark
> William's,
> > I calculate a specific feedrate for each step increment so that it
> cuts
> > smoothly.
> >
> > Would you like a copy of my spreadsheet?
> >
> > Daniel J. Statman, Statman Designs
> > www.statmandesigns.com
> >
> >
> > ----- Original Message -----
> > From: "John Guenther" <j.guenther@v...>
> > To: <CAD_CAM_EDM_DRO@y...>
> > Sent: Wednesday, August 21, 2002 6:32 PM
> > Subject: RE: [CAD_CAM_EDM_DRO] RE: Cam track help!
> >
> >
> > > Dan,
> > >
> > > Ok, thanks that helps. Would there be anything gained by
> recalculating it
> > > at 0.5 degree or smaller increments instead of the 1 degree
> increments? I
> > > suppose I could do that and run it on the mill just to see how it
> acts.
> > > When I ran the original gcode I produced it acted a little
> strange at the
> > > peaks but seemed fine other wise.
> > >
> > > john
> > >
>
>
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